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1
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Okekpa SI, Mydin RBSMN, Ganeson S, Gopalan S, Musa MY. The Association between Tea Consumption and Nasopharyngeal
Cancer: A Systematic Review and Meta-Analysis. Asian Pac J Cancer Prev 2020; 21:2183-2187. [PMID: 32856842 PMCID: PMC7771920 DOI: 10.31557/apjcp.2020.21.8.2183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 07/22/2020] [Indexed: 11/25/2022] Open
Abstract
Heated debates have been on-going about tea consumption and the incidence of cancer, especially in head and neck cancer types. This study aimed to review the association between tea consumption habits and nasopharyngeal cancer (NPC). Methods: This review was carried out in accordance with the PRISMA-P protocol. Literature search for journal articles that published studies on the relationship between tea consumption and NPC was performed via databases, such as Elsevier, PubMed, Science Direct, Springer Link, Google, and Google Scholar, for 10 years from 2008 to 2018. Relevant studies were obtained by applying the pre-determined keywords, such as nasopharyngeal cancer, tea consumption and NPC, risk factors of NPC and benefits of tea consumption. Results: A total of 126 articles was retrieved. These articles were subjected to eligibility assessment. Six articles remained after applying the inclusion criteria. Results suggest that habitual tea consumption reduces NPC. Tea consumption significantly reduces NPC with all the studies having a p-value ≤0.05. Meta-analysis showed statistical association between tea consumption and NPC risk with OR=0.865 at 95% CI (0.806-0.929). Conclusion: This study suggests that habitual tea consumption could be associated with prevention of NPC development. Additional studies are needed to further understand the molecular role of bioactive compound and potential health benefit of tea consumption in NPC prevention.
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Affiliation(s)
- Simon I Okekpa
- Oncological and Radiological Sciences Cluster, Advanced Medical and Dental Institute, Universiti Sains Malaysia, 13200 Bertam, Kepala Batas, Pulau Pinang Malaysia.
- Department of Medical Laboratory Science, Faculty of Health Sciences, Ebonyi State University, Abakaliki, 840001 Ebonyi state, Nigeria.
| | - Rabiatul Basria S. M. N. Mydin
- Oncological and Radiological Sciences Cluster, Advanced Medical and Dental Institute, Universiti Sains Malaysia, 13200 Bertam, Kepala Batas, Pulau Pinang Malaysia.
- School of Distance Education, Universiti Sains Malaysia, Penang, Malaysia.
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, 117543 Singapore.
| | - Sivaraj Ganeson
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, 117543 Singapore.
| | - Saravanackumar Gopalan
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, 117543 Singapore.
| | - Muhamad Yusri Musa
- Oncological and Radiological Sciences Cluster, Advanced Medical and Dental Institute, Universiti Sains Malaysia, 13200 Bertam, Kepala Batas, Pulau Pinang Malaysia.
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2
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Genetic polymorphism of catechol-O-methyltransferase modulates the association of green tea consumption and lung cancer. Eur J Cancer Prev 2020; 28:316-322. [PMID: 30157136 DOI: 10.1097/cej.0000000000000464] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Tea polyphenols are strong antioxidants, which can be rapidly O-methylated by catechol-O-methyltransferase (COMT). Thus, it is possible that the genetic polymorphism of COMT can modulate the association of green tea consumption and lung cancer. Here, we designed a case-control study to evaluate the combined effect of green tea consumption and COMT genotypes on the risk of lung cancer. A total of 237 lung cancer patients and 474 healthy controls were recruited. Questionnaires were administered to obtain demographic data, smoking status, green tea consumption, fruits and vegetables intake, exposure to cooking fumes, and family history of lung cancer. Genotypes for COMT were identified by PCR. Smoking, green tea consumption, exposure to cooking fumes, and family history of lung cancer were associated with the development of lung cancer. When green tea drinkers carrying COMT HL/LL genotypes were selected as the reference group, drinkers carrying the COMT HH genotype had a higher risk for the development of lung cancer (odds ratio: 1.97, 95% confidence interval: 0.99-3.91). Among the current and ever smokers, the elevated risk for lung cancer was more apparent in green tea drinkers carrying the COMT HH genotype compared with green tea drinkers carrying COMT HL/LL genotypes (odds ratio: 5.84, 95% confidence interval: 1.75-19.45). Green tea drinkers with greater activity of the COMT genotype, whereby polyphenols are effectively excluded, will gain fewer protective benefits against lung cancer development.
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3
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Zhu MZ, Lu DM, Ouyang J, Zhou F, Huang PF, Gu BZ, Tang JW, Shen F, Li JF, Li YL, Lin HY, Li J, Zeng X, Wu JL, Cai SX, Wang KB, Huang JA, Liu ZH. Tea consumption and colorectal cancer risk: a meta-analysis of prospective cohort studies. Eur J Nutr 2020; 59:3603-3615. [PMID: 32078065 DOI: 10.1007/s00394-020-02195-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Accepted: 01/28/2020] [Indexed: 12/22/2022]
Abstract
PURPOSE Data from in vitro and animal studies support the preventive effect of tea (Camellia sinensis) against colorectal cancer. Further, many epidemiologic studies evaluated the association between tea consumption and colorectal cancer risk, but the results were inconsistent. We conducted a meta-analysis of prospective cohort studies to systematically assess the association between tea consumption and colorectal cancer risk. METHODS A comprehensive literature review was conducted to identify the related articles by searching PubMed and Embase up to June, 2019. Summary relative risks (RRs) and 95% confidence intervals (CIs) were calculated using a fixed effect model. RESULTS Twenty cohort articles were included in the present meta-analysis involving 2,068,137 participants and 21,437 cases. The combined RR of colorectal cancer for the highest vs. lowest tea consumption was determined to 0.97 (95% CI 0.94-1.01) with marginal heterogeneity (I2 = 24.0%, P = 0.093) among all studies. This indicated that tea consumption had no significant association with colorectal cancer risk. Stratified analysis showed that no significant differences were found in all subgroups. We further conducted the gender-specific meta-analysis for deriving a more precise estimation. No significant association was observed between tea consumption and colorectal cancer risk in male (combined RR = 0.97; 95% CI 0.90-1.04). However, tea consumption had a marginal significant inverse impact on colorectal cancer risk in female (combined RR = 0.93; 95% CI 0.86-1.00). Further, we found a stronger inverse association between tea consumption and risk of colorectal cancer among the female studies with no adjustment of coffee intake (RR: 0.90; 95% CI 0.82-1.00, P < 0.05) compared to the female studies that adjusted for coffee intake (RR = 0.97; 95% CI 0.87-1.09, P > 0.05). CONCLUSIONS Our finding indicates that tea consumption has no significant impact on the colorectal cancer risk in both genders combined, but gender-specific meta-analysis shows that tea consumption has a marginal significant inverse impact on colorectal cancer risk in female.
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Affiliation(s)
- Ming-Zhi Zhu
- Key Laboratory of Tea Science of Ministry of Education, National Research Center of Engineering Technology for Utilization of Functional Ingredients from Botanicals, College of Horticulture, Hunan Agricultural University, Changsha, 410128, China.,Hunan Provincial Key Laboratory for Germplasm Innovation and Utilization of Crop, Hunan Agricultural University, Changsha, 410128, China
| | - Dan-Min Lu
- Key Laboratory of Tea Science of Ministry of Education, National Research Center of Engineering Technology for Utilization of Functional Ingredients from Botanicals, College of Horticulture, Hunan Agricultural University, Changsha, 410128, China
| | - Jian Ouyang
- Key Laboratory of Tea Science of Ministry of Education, National Research Center of Engineering Technology for Utilization of Functional Ingredients from Botanicals, College of Horticulture, Hunan Agricultural University, Changsha, 410128, China
| | - Fang Zhou
- Key Laboratory of Tea Science of Ministry of Education, National Research Center of Engineering Technology for Utilization of Functional Ingredients from Botanicals, College of Horticulture, Hunan Agricultural University, Changsha, 410128, China
| | - Pei-Fang Huang
- Key Laboratory of Tea Science of Ministry of Education, National Research Center of Engineering Technology for Utilization of Functional Ingredients from Botanicals, College of Horticulture, Hunan Agricultural University, Changsha, 410128, China
| | - Bao-Zheng Gu
- Key Laboratory of Tea Science of Ministry of Education, National Research Center of Engineering Technology for Utilization of Functional Ingredients from Botanicals, College of Horticulture, Hunan Agricultural University, Changsha, 410128, China
| | - Jun-Wei Tang
- Key Laboratory of Tea Science of Ministry of Education, National Research Center of Engineering Technology for Utilization of Functional Ingredients from Botanicals, College of Horticulture, Hunan Agricultural University, Changsha, 410128, China
| | - Fan Shen
- Key Laboratory of Tea Science of Ministry of Education, National Research Center of Engineering Technology for Utilization of Functional Ingredients from Botanicals, College of Horticulture, Hunan Agricultural University, Changsha, 410128, China
| | - Jia-Feng Li
- Key Laboratory of Tea Science of Ministry of Education, National Research Center of Engineering Technology for Utilization of Functional Ingredients from Botanicals, College of Horticulture, Hunan Agricultural University, Changsha, 410128, China
| | - Yi-Long Li
- Key Laboratory of Tea Science of Ministry of Education, National Research Center of Engineering Technology for Utilization of Functional Ingredients from Botanicals, College of Horticulture, Hunan Agricultural University, Changsha, 410128, China
| | - Hai-Yan Lin
- Key Laboratory of Tea Science of Ministry of Education, National Research Center of Engineering Technology for Utilization of Functional Ingredients from Botanicals, College of Horticulture, Hunan Agricultural University, Changsha, 410128, China
| | - Juan Li
- Key Laboratory of Tea Science of Ministry of Education, National Research Center of Engineering Technology for Utilization of Functional Ingredients from Botanicals, College of Horticulture, Hunan Agricultural University, Changsha, 410128, China
| | - Xin Zeng
- College of Life Sciences, Huaibei Normal University, Huaibei, 235000, China.
| | - Jian-Lin Wu
- State Key Laboratory for Quality Research of Chinese Medicines, Macau University of Science and Technology, Avenida Wai Long, Taipa, Macao, 999078, China
| | - Shu-Xian Cai
- Key Laboratory of Tea Science of Ministry of Education, National Research Center of Engineering Technology for Utilization of Functional Ingredients from Botanicals, College of Horticulture, Hunan Agricultural University, Changsha, 410128, China
| | - Kun-Bo Wang
- Key Laboratory of Tea Science of Ministry of Education, National Research Center of Engineering Technology for Utilization of Functional Ingredients from Botanicals, College of Horticulture, Hunan Agricultural University, Changsha, 410128, China
| | - Jian-An Huang
- Key Laboratory of Tea Science of Ministry of Education, National Research Center of Engineering Technology for Utilization of Functional Ingredients from Botanicals, College of Horticulture, Hunan Agricultural University, Changsha, 410128, China
| | - Zhong-Hua Liu
- Key Laboratory of Tea Science of Ministry of Education, National Research Center of Engineering Technology for Utilization of Functional Ingredients from Botanicals, College of Horticulture, Hunan Agricultural University, Changsha, 410128, China.
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Abstract
Metastasis of cells from primary site to distant organs involves a series of sequential steps, and molecules responsible for all these events are understandably considered as potential targets for metastasis management. Tea polyphenols, the secondary metabolites of the tea leaf Camellia sinensis, are increasingly being studied for their antimetastatic properties. In this article, effects of green tea polyphenols (GTP) and black tea polyphenols (BTP) on the molecules and events involved in metastasis are discussed in detail. As tea is a very popular beverage, tea polyphenols are expected to be potential chemopreventive agents that can be taken with normal diet and can be nontoxic due to their natural origin. However, individual variations in metabolic pathways, bioavailability, dose, and toxicity are some important factors that can modify the effectiveness of tea polyphenols within the human system.
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Affiliation(s)
- Niladri Bag
- Department of Horticulture, Sikkim University, Gangtok, India
| | - Arundhati Bag
- Department of Medical Biotechnology, Sikkim Manipal Institute of Medical Sciences, Sikkim Manipal University, Gangtok, India
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5
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Chen Y, Wu Y, Du M, Chu H, Zhu L, Tong N, Zhang Z, Wang M, Gu D, Chen J. An inverse association between tea consumption and colorectal cancer risk. Oncotarget 2018; 8:37367-37376. [PMID: 28454102 PMCID: PMC5514915 DOI: 10.18632/oncotarget.16959] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 03/29/2017] [Indexed: 12/13/2022] Open
Abstract
It is well known that the tea extracts, mainly polyphenols as chemo-preventive elements, could act as cancer progression blockers. Although the association between tea consumption and colorectal cancer risk has been widely investigated, the results still remain inconsistent. We conducted a dose-response meta-analysis to evaluate their relationships by enrolling qualified 29 literatures. The summary odds ratio (OR) of colorectal cancer for the highest vs. lowest tea consumption was 0.93 with 0.87–1.00 of 95% confidence intervals (CIs) among all studies with modest heterogeneity (P = 0.001, I2 = 43.4%). Stratified analysis revealed that tea, especially green tea, had a protective effect among female and rectal cancer patients. Particularly, the dose-response analysis showed that there was a significant inverse association between an increment of 1 cup/day of tea consumption and colorectal cancer risk in the subgroup of the green tea drinking (OR = 0.98, 95% CI = 0.96–1.01, Pnonlinear = 0.003) and female (OR = 0.68, 95% CI = 0.56-0.81, Pnonlinear < 0.001). Our findings indicate that tea consumption has an inverse impact on colorectal cancer risk, which may have significant public health implications in the prevention of colorectal cancer and further similar researches.
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Affiliation(s)
- Yuetong Chen
- Department of Oncology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China.,Department of Environmental Genomics, Jiangsu Key Laboratory of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center for Cancer Personalized Medicine, Nanjing Medical University, Nanjing, China
| | - Yuan Wu
- Department of Medical Oncology, Jiangsu Cancer Hospital, Nanjing Medical University, Nanjing, China
| | - Mulong Du
- Department of Environmental Genomics, Jiangsu Key Laboratory of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center for Cancer Personalized Medicine, Nanjing Medical University, Nanjing, China.,Department of Genetic Toxicology, The Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing, China.,Department of Biostatistics, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Haiyan Chu
- Department of Environmental Genomics, Jiangsu Key Laboratory of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center for Cancer Personalized Medicine, Nanjing Medical University, Nanjing, China
| | - Lingjun Zhu
- Department of Oncology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Na Tong
- Department of Environmental Genomics, Jiangsu Key Laboratory of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center for Cancer Personalized Medicine, Nanjing Medical University, Nanjing, China
| | - Zhengdong Zhang
- Department of Environmental Genomics, Jiangsu Key Laboratory of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center for Cancer Personalized Medicine, Nanjing Medical University, Nanjing, China.,Department of Genetic Toxicology, The Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Meilin Wang
- Department of Environmental Genomics, Jiangsu Key Laboratory of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center for Cancer Personalized Medicine, Nanjing Medical University, Nanjing, China.,Department of Genetic Toxicology, The Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Dongying Gu
- Department of Oncology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
| | - Jinfei Chen
- Department of Oncology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China.,Department of Environmental Genomics, Jiangsu Key Laboratory of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center for Cancer Personalized Medicine, Nanjing Medical University, Nanjing, China
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6
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van den Brandt PA. Coffee or Tea? A prospective cohort study on the associations of coffee and tea intake with overall and cause-specific mortality in men versus women. Eur J Epidemiol 2018; 33:183-200. [PMID: 29380105 PMCID: PMC5871637 DOI: 10.1007/s10654-018-0359-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 01/16/2018] [Indexed: 12/25/2022]
Abstract
Coffee and tea intake have been associated with reduced mortality, but no studies have investigated possible substitution effects. The relationship of mortality with coffee, tea, and substituting coffee with tea was investigated in the Netherlands Cohort Study. In 1986, 120,852 men and women aged 55-69 years provided information on dietary and lifestyle habits. Mortality follow-up until 1996 consisted of linkage to Statistics Netherlands. Multivariate case-cohort analyses were based on 8665 deaths and 3166 subcohort members with complete data on coffee, tea and confounders. Higher coffee intake was significantly, nonlinearly related to lower overall and cause-specific mortality in women. In men, coffee was significantly positively related to cancer and cardiovascular mortality, and inversely to respiratory and other causes of death. Tea intake was significantly, nonlinearly related to lower overall, cancer and cardiovascular mortality in men, but showed no association with mortality in women. In substitution analyses, increasing the proportion tea (replacing coffee with tea) was significantly and nonlinearly related to lower overall, cancer and cardiovascular mortality in men, but in women higher tea proportions were positively associated with overall mortality (and most causes of death). This study suggests that for men, compared to exclusive coffee drinkers, those drinking 30-50% tea showed the lowest mortality; any tea drinking seemed better than only coffee. For women, those who drank exclusively coffee or drinking up to 40% tea had the lowest mortality, but those drinking higher percentages of tea were at increased mortality risk [HR = 1.41 (95% CI 1.01-1.99) for 80-100% tea compared to exclusive coffee drinkers].
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Affiliation(s)
- Piet A van den Brandt
- Department of Epidemiology, GROW-School for Oncology and Developmental Biology, Maastricht University Medical Centre, PO Box 616, 6200 MD, Maastricht, The Netherlands. .,Department of Epidemiology, CAPHRI-School for Public Health and Primary Care, Maastricht University Medical Centre, PO Box 616, 6200 MD, Maastricht, The Netherlands.
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7
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Abstract
Tea polyphenols are secondary metabolites of tea plants and are well known for beneficial health effects. They can protect from a variety of illnesses including cancers. Tea polyphenols can prevent cancer by modulating epigenetic aberrations taking place in DNA methylation, histone modifications, and micro-RNAs. By altering these epimutations, they regulate chromatin dynamics and expression of genes those induce or suppress cancer formation. However, majority of the studies in existing literature are carried out for green tea polyphenols rather than black tea polyphenols despite the fact that black tea is the most commonly consumed form of tea (78%) followed by green tea (20%) and other forms of tea. Research findings indicate that tea polyphenols may be potential source from which drugs with less side effects and affordable price can be developed.
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Affiliation(s)
- Arundhati Bag
- Department of Medical Biotechnology, Sikkim Manipal Institute of Medical Sciences, Sikkim Manipal University, Gangtok, Sikkim, India
| | - Niladri Bag
- Department of Horticulture, Sikkim University, Gangtok, Sikkim, India
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8
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Malongane F, McGaw LJ, Mudau FN. The synergistic potential of various teas, herbs and therapeutic drugs in health improvement: a review. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2017; 97:4679-4689. [PMID: 28585285 DOI: 10.1002/jsfa.8472] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 05/29/2017] [Accepted: 05/31/2017] [Indexed: 06/07/2023]
Abstract
Tea is one of the most widely consumed non-alcoholic beverages in the world next to water. It is classified as Camellia sinensis and non-Camellia sinensis (herbal teas). The common bioactive compounds found mainly in green teas are flavan-3-ols (catechins) (also called flavanols), proanthocyanidins (tannins) and flavonols. Black tea contains theaflavins and thearubigins and white tea contains l-theanine and gamma-aminobutyric acid (GABA), while herbal teas contain diverse polyphenols. Phytochemicals in tea exhibit antimicrobial, anti-diabetic and anti-cancer activities that are perceived to be helpful in managing chronic diseases linked to lifestyle. Many of these phytochemicals are reported to be biologically active when combined. Knowledge of the synergistic interactions of tea with other teas or herbs in terms of biological activities will be of benefit for therapeutic enhancement. There is evidence that various types of teas act synergistically in exhibiting health benefits to humans, improving consumer acceptance and economic value. Similar observations have been made when teas and herbs or medicinal drugs were combined. The aim of this review is to highlight potential beneficial synergies between combinations of different types of teas, tea and herbs, and tea and medicinal drugs. © 2017 Society of Chemical Industry.
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Affiliation(s)
- Florence Malongane
- Department Life and Consumer Sciences, College of Agriculture and Environmental Sciences, University of South Africa, Florida, South Africa
| | - Lyndy J McGaw
- Phytomedicine Programme, Department of Paraclinical Sciences, University of Pretoria, Pretoria, South Africa
| | - Fhatuwani N Mudau
- Department of Agriculture and Animal Health, College of Agriculture and Environmental Sciences, University of South Africa, Florida, South Africa
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9
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Pan H, Wang F, Rankin GO, Rojanasakul Y, Tu Y, Chen YC. Inhibitory effect of black tea pigments, theaflavin‑3/3'-gallate against cisplatin-resistant ovarian cancer cells by inducing apoptosis and G1 cell cycle arrest. Int J Oncol 2017; 51:1508-1520. [PMID: 29048667 PMCID: PMC5642389 DOI: 10.3892/ijo.2017.4145] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 09/26/2017] [Indexed: 12/26/2022] Open
Abstract
Adverse side effects and acquired resistance to conventional chemotherapy based on platinum drive the exploration of other selective anticancer drugs. Theaflavin-3-gallate (TF2a) and theaflavin-3′-gallate (TF2b), theaflavin monomers in black tea, exhibited a potent growth inhibitory effect on cisplatin-resistant ovarian cancer A2780/CP70 cells and were less cytotoxic to normal ovarian IOSE-364 cell line. Flow cytometry analysis and western blotting indicated that TF2a and TF2b induced apoptosis and G1 cell cycle arrest in ovarian cancer A2780/CP70 cells. Hoechst 33342 staining was used to confirm the apoptotic effect. Downregulation of CDK2 and CDK4 for TF2a and CDK2 and cyclin E1 for TF2b led to the accumulation of cells in G1 phase. TF2a and TF2b induced apoptosis and G1 through p53-dependent pathways. TF2a and TF2b induced DNA damage through ATM/Chk/p53 pathway. TF2a and TF2b also induced inhibition of A2780/CP70 cells through Akt and MAPK pathways. The results of this study implied that TF2a and TF2b might help prevent and treat platinum-resistant ovarian cancer.
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Affiliation(s)
- Haibo Pan
- Department of Tea Science, Zhejiang University, Hangzhou, Zhejiang, P.R. China
| | - Fang Wang
- Department of Tea Science, Wuyi University, Wuyishan, Fujian, P.R. China
| | - Gary O Rankin
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV, USA
| | - Yon Rojanasakul
- Department of Pharmaceutical Sciences, West Virginia University, Morgantown, WV, USA
| | - Youying Tu
- Department of Tea Science, Zhejiang University, Hangzhou, Zhejiang, P.R. China
| | - Yi Charlie Chen
- College of Science, Technology and Mathematics, Alderson Broaddus University, Philippi, WV, USA
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10
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Leung ACY, Cook LS, Swenerton K, Gilks B, Gallagher RP, Magliocco A, Steed H, Köbel M, Nation J, Brooks-Wilson A, Le ND. Tea, coffee, and caffeinated beverage consumption and risk of epithelial ovarian cancers. Cancer Epidemiol 2016; 45:119-125. [PMID: 27810483 DOI: 10.1016/j.canep.2016.10.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 10/13/2016] [Accepted: 10/16/2016] [Indexed: 12/25/2022]
Abstract
BACKGROUND The risk for epithelial ovarian cancer associated with the consumption of caffeinated beverages (tea, coffee, and soft drinks) and green tea is inconclusive. However, few studies have investigated the type of caffeinated beverage or the type of tea. OBJECTIVE We assessed consumption of tea (black/caffeinated tea and green tea separately), coffee, and caffeinated soft drinks, as well as level of consumption, and the risk for epithelial ovarian cancer and its histotypes. STUDY DESIGN This study was conducted within a population-based case-control study in Alberta and British Columbia, Canada from 2001 to 2012. After restricting to cases of epithelial invasive cancers and controls aged 40-79 years who completed an interview that included coffee, soft drink, and tea consumption (ascertained starting in 2005 in British Columbia and 2008 in Alberta), there were a total of 524 cases and 1587 controls. Those that did not meet the threshold for beverage consumption (at least once per month for 6 months or more) were classified as non-drinkers. Adult lifetime cumulative consumption (cup-years=cups/day*years) was calculated. Unconditional logistic regression was used to estimate adjusted odds ratios (aOR) and 95% confidence intervals (CI) to describe the association between the relevant drink consumption and risk. RESULTS No excess risk was seen for coffee or caffeinated soft drinks. Similarly, any tea consumption was not associated with risk, but when stratified by the type of tea, there was an increase in risk in black tea only drinkers (aOR=1.56; 95% CI:1.07-2.28 for >40 cup-years), but no excess risk for the exclusive green tea drinkers. Similar findings were observed for post-menopausal women. The association for black tea only consumption was mainly seen in the endometrioid histotype (aOR=3.19; 95% CI: 1.32-7.69). CONCLUSION Black tea consumption may be associated with an increased risk epithelial ovarian carcinoma. The excess risk is seen only in the endometrioid histotype but not in serous or clear cell. Further studies are required to confirm these findings and identify the constituents in black tea that may increase the risk.
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Affiliation(s)
- Andy C Y Leung
- Cancer Control Research, BC Cancer Research Centre, Vancouver, British Columbia, Canada
| | - Linda S Cook
- Department of Internal Medicine, University of New Mexico and UNM Comprehensive Cancer Center, Albuquerque, NM, USA; Department of Community Health Sciences, University of Calgary, Calgary, Alberta, Canada; Alberta Health Services, Calgary, Alberta, Canada
| | - Kenneth Swenerton
- Medical Oncology, BC Cancer Agency, Vancouver, British Columbia, Canada
| | - Blake Gilks
- Department of Pathology, Vancouver General Hospital and British Columba Cancer Agency, Vancouver, British Columbia, Canada
| | - Richard P Gallagher
- Cancer Control Research, BC Cancer Research Centre, Vancouver, British Columbia, Canada
| | - Anthony Magliocco
- Department of Anatomic Pathology, H Lee Moffitt Cancer Center, Tampa, FL, USA
| | - Helen Steed
- Department of Obstetrics and Gynecology, University of Alberta, Edmonton, Alberta, Canada
| | - Martin Köbel
- Department of Pathology & Laboratory Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Jill Nation
- Department of Oncology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Angela Brooks-Wilson
- Canada's Michael Smith Genome Sciences Centre, BC Cancer Agency, Vancouver, British Columbia, Canada; Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Nhu D Le
- Cancer Control Research, BC Cancer Research Centre, Vancouver, British Columbia, Canada.
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11
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Pasquet R, Karp I, Siemiatycki J, Koushik A. The consumption of coffee and black tea and the risk of lung cancer. Ann Epidemiol 2016; 26:757-763.e2. [PMID: 27743642 DOI: 10.1016/j.annepidem.2016.09.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Revised: 07/16/2016] [Accepted: 09/09/2016] [Indexed: 12/15/2022]
Abstract
PURPOSE Coffee and black tea are among the most consumed beverages worldwide. Although their potential role in lung cancer occurrence has been investigated in several studies, results have been inconclusive. We investigated the associations between intake of coffee and black tea with lung cancer in a population-based case-control study in Montreal, Canada. METHODS These analyses included 1130 cases and 1483 controls. Adjusted odds ratios (ORs) were estimated between four metrics of coffee and black tea consumption (frequency, average daily amount, duration, and cumulative amount) and lung cancer, using unconditional logistic regression. RESULTS The adjusted ORs (95% confidence intervals) for lung cancer comparing daily to never consumers were 0.73 (0.49-1.10) for coffee and 1.05 (0.85-1.31) for black tea. Analyses of other metrics did not reveal any clear patterns of increasing or decreasing risk with increasing amounts or duration of consumption. There was no strong evidence of OR modification by sex or smoking level. The OR estimates did not materially differ by histological subtype for either of the beverages. CONCLUSION Our results do not provide strong support for associations between consumption of coffee and black tea and lung cancer.
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Affiliation(s)
- Romain Pasquet
- Département de médecine sociale et préventive, Université de Montréal, Montréal, Canada; Risks, Prevention, and Health Promotion Research Axis, Université de Montréal Hospital Research Centre (CRCHUM), Montréal, Canada
| | - Igor Karp
- Risks, Prevention, and Health Promotion Research Axis, Université de Montréal Hospital Research Centre (CRCHUM), Montréal, Canada; Department of Epidemiology and Biostatistics, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Canada
| | - Jack Siemiatycki
- Département de médecine sociale et préventive, Université de Montréal, Montréal, Canada; Risks, Prevention, and Health Promotion Research Axis, Université de Montréal Hospital Research Centre (CRCHUM), Montréal, Canada
| | - Anita Koushik
- Département de médecine sociale et préventive, Université de Montréal, Montréal, Canada; Risks, Prevention, and Health Promotion Research Axis, Université de Montréal Hospital Research Centre (CRCHUM), Montréal, Canada.
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12
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Singh D, Upadhyay G, Srivastava RK, Shankar S. Recent advances in pancreatic cancer: biology, treatment, and prevention. Biochim Biophys Acta Rev Cancer 2015; 1856:13-27. [PMID: 25977074 DOI: 10.1016/j.bbcan.2015.04.003] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 04/28/2015] [Accepted: 04/30/2015] [Indexed: 02/07/2023]
Abstract
Pancreatic cancer (PC) is the fourth leading cause of cancer-related death in United States. Efforts have been made towards the development of the viable solution for its treatment with constrained accomplishment because of its complex biology. It is well established that pancreatic cancer stem cells (CSCs), albeit present in a little count, contribute incredibly to PC initiation, progression, and metastasis. Customary chemo and radiotherapeutic alternatives, however, expands general survival, the related side effects are the significant concern. Amid the most recent decade, our insight about molecular and cellular pathways involved in PC and role of CSCs in its progression has increased enormously. Presently the focus is to target CSCs. The herbal products have gained much consideration recently as they, usually, sensitize CSCs to chemotherapy and target molecular signaling involved in various tumors including PC. Some planned studies have indicated promising results proposing that examinations in this course have a lot to offer for the treatment of PC. Although preclinical studies uncovered the importance of herbal products in attenuating pancreatic carcinoma, limited studies have been conducted to evaluate their role in clinics. The present review provides a new insight to recent advances in pancreatic cancer biology, treatment and current status of herbal products in its anticipation.
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Affiliation(s)
- Divya Singh
- Department of Biology, City College of New York, 160 Convent Avenue, New York, NY 10031, USA.
| | - Ghanshyam Upadhyay
- Department of Biology, City College of New York, 160 Convent Avenue, New York, NY 10031, USA.
| | - Rakesh K Srivastava
- Kansas City VA Medical Center, 4801 Linwood Boulevard, Kansas City, MO 64128, USA.
| | - Sharmila Shankar
- Kansas City VA Medical Center, 4801 Linwood Boulevard, Kansas City, MO 64128, USA; Department of Pathology, School of Medicine, University of Missouri-Kansas City, Kansas City, MO 64108, USA.
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Oh JK, Sandin S, Ström P, Löf M, Adami HO, Weiderpass E. Prospective study of breast cancer in relation to coffee, tea and caffeine in Sweden. Int J Cancer 2015; 137:1979-89. [PMID: 25885188 DOI: 10.1002/ijc.29569] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 04/07/2015] [Indexed: 02/01/2023]
Abstract
Studies of coffee and tea consumption and caffeine intake as risk factors for breast cancer are inconclusive. We assessed coffee and tea consumption, caffeine intake, and possible confounding factors among 42,099 women from the Swedish Women's Lifestyle and Health study, the participants of which were aged 30-49 years at enrollment in 1991-1992. Complete follow-up for breast cancer incidence was performed through 2012 via linkage to national registries. Poisson regression models were used to estimate relative risks (RRs) and 95% confidence intervals (CIs) for breast cancer. During follow-up 1,395 breast cancers were diagnosed. The RR was 0.97 (95% CI 0.94-0.99) for a 1-unit increase in cups of coffee/day, 1.14 (95% CI 1.05-1.24) for a 1-unit increase in cups of tea/day, and 0.97 (95% CI 0.95-1.00) for a 100 mg/day increase in caffeine intake. Although the RR for no consumption (RR = 0.86, 95% CI 0.69-1.08), a group with a relatively small number of women, was not statistically significant, women with higher consumption had a decreased breast cancer risk (3-4 cups/day: RR = 0.87, 95% CI 0.76-1.00; ≥5 cups/day: RR = 0.81, 95% CI 0.70-0.94) compared to women consuming 1-2 cups of coffee/day. Compared to no consumption, women consuming >1 cups tea/day showed an increased breast cancer risk (RR = 1.19, 95% CI 1.00-1.42). Similar patterns of estimates were observed for breast cancer risk overall, during pre- and postmenopausal years, and for ER+ or PR+ breast cancer, but not for ER- and PR- breast cancer. Our findings suggest that coffee consumption and caffeine intake is negatively associated with the risk of overall and ER+/PR- breast cancer, and tea consumption is positively associated with the risk of overall and ER+/PR+ breast cancer.
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Affiliation(s)
- Jin-Kyoung Oh
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.,Department of Cancer Control Policy, Graduate School of Cancer Science and Policy, and National Cancer Control Institute, National Cancer Center, Goyang, Republic of Korea
| | - Sven Sandin
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Peter Ström
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Marie Löf
- Department of Biosciences and Nutrition, Karolinska Institutet, Stockholm, Sweden
| | - Hans-Olov Adami
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.,Department of Epidemiology, Harvard School of Public Health, Boston, MA, USA
| | - Elisabete Weiderpass
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.,Department of Research, The Cancer Registry of Norway, Oslo, Norway.,Department of Genetic Epidemiology, Folkhälsan Research Center, Helsinki, Finland.,Department of Community Medicine, Faculty of Health Sciences, University of Tromsø, The Arctic University of Norway, Tromsø, Norway
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Sanikini H, Dik VK, Siersema PD, Bhoo-Pathy N, Uiterwaal CSPM, Peeters PHM, González CA, Zamora-Ros R, Overvad K, Tjønneland A, Roswall N, Boutron-Ruault MC, Fagherazzi G, Racine A, Kühn T, Katzke V, Boeing H, Trichopoulou A, Trichopoulos D, Lagiou P, Palli D, Grioni S, Vineis P, Tumino R, Panico S, Weiderpass E, Skeie G, Braaten T, Huerta JM, Sánchez-Cantalejo E, Barricarte A, Sonestedt E, Wallstrom P, Nilsson LM, Johansson I, Bradbury KE, Khaw KT, Wareham N, Huybrechts I, Freisling H, Cross AJ, Riboli E, Bueno-de-Mesquita HB. Total, caffeinated and decaffeinated coffee and tea intake and gastric cancer risk: results from the EPIC cohort study. Int J Cancer 2015; 136:E720-30. [PMID: 25236393 DOI: 10.1002/ijc.29223] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Revised: 08/12/2014] [Accepted: 08/15/2014] [Indexed: 01/13/2023]
Abstract
Prospective studies examining the association between coffee and tea consumption and gastric cancer risk have shown inconsistent results. We investigated the association between coffee (total, caffeinated and decaffeinated) and tea consumption and the risk of gastric cancer by anatomical site and histological type in the European Prospective Investigation into Cancer and Nutrition study. Coffee and tea consumption were assessed by dietary questionnaires at baseline. Adjusted hazard ratios (HRs) were calculated using Cox regression models. During 11.6 years of follow up, 683 gastric adenocarcinoma cases were identified among 477,312 participants. We found no significant association between overall gastric cancer risk and consumption of total coffee (HR 1.09, 95%-confidence intervals [CI]: 0.84-1.43; quartile 4 vs. non/quartile 1), caffeinated coffee (HR 1.14, 95%-CI: 0.82-1.59; quartile 4 vs. non/quartile 1), decaffeinated coffee (HR 1.07, 95%-CI: 0.75-1.53; tertile 3 vs. non/tertile 1) and tea (HR 0.81, 95%-CI: 0.59-1.09; quartile 4 vs. non/quartile 1). When stratified by anatomical site, we observed a significant positive association between gastric cardia cancer risk and total coffee consumption per increment of 100 mL/day (HR 1.06, 95%-CI: 1.03-1.11). Similarly, a significant positive association was observed between gastric cardia cancer risk and caffeinated coffee consumption (HR 1.98, 95%-CI: 1.16-3.36, p-trend=0.06; quartile 3 vs. non/quartile 1) and per increment of 100 mL/day (HR 1.09, 95%-CI: 1.04-1.14). In conclusion, consumption of total, caffeinated and decaffeinated coffee and tea is not associated with overall gastric cancer risk. However, total and caffeinated coffee consumption may be associated with an increased risk of gastric cardia cancer. Further prospective studies are needed to rule out chance or confounding.
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Affiliation(s)
- Harinakshi Sanikini
- Department of Gastroenterology and Hepatology, University Medical Centre Utrecht, Utrecht, The Netherlands; Inserm, Centre for research in Epidemiology and Population Health (CESP), U1018, Environmental Epidemiology of Cancer Team, Villejuif, Paris, France; Univ Paris Sud, UMRS 1018, Villejuif, Paris, France
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15
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Nie XC, Dong DS, Bai Y, Xia P. Meta-Analysis of Black Tea Consumption and Breast Cancer Risk: Update 2013. Nutr Cancer 2014; 66:1009-14. [DOI: 10.1080/01635581.2014.936947] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Yang CS, Chen G, Wu Q. Recent scientific studies of a traditional chinese medicine, tea, on prevention of chronic diseases. J Tradit Complement Med 2014; 4:17-23. [PMID: 24872929 PMCID: PMC4032838 DOI: 10.4103/2225-4110.124326] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Green tea (綠茶 Lǜ Chá), made from the leaves of the plant Camellia sinensis, has traditionally been used as a medicine in China for thousands of years. According to the classical work of Li Shizhen (李時珍 Lǐ Shí Zhēn) of the Ming Dynasty, “tea is cold and lowers the fire.” Since fire (inflammation) causes many diseases, could tea be effective in the prevention of many diseases? The possible prevention of chronic diseases such as cancer, metabolic syndrome, obesity, diabetes, and cardiovascular diseases has been studied with contemporary scientific methods, and the results are promising. The molecular mechanisms underlining these observations will be discussed in this presentation. One of the reasons for the failure to demonstrate a disease-preventive effect of tea in some epidemiological studies is the lower quantities of tea consumption in humans. Can we increase the quantity of tea consumption to harness its health benefits without causing gastrointestinal irritation? This is a topic for further research.
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Affiliation(s)
- Chung S Yang
- Department of Chemical Biology, Center for Cancer Prevention Research, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, NJ, USA
| | - Gang Chen
- Department of Chemical Biology, Center for Cancer Prevention Research, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, NJ, USA
| | - Qing Wu
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, China
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Yu F, Jin Z, Jiang H, Xiang C, Tang J, Li T, He J. Tea consumption and the risk of five major cancers: a dose-response meta-analysis of prospective studies. BMC Cancer 2014; 14:197. [PMID: 24636229 PMCID: PMC4004325 DOI: 10.1186/1471-2407-14-197] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Accepted: 03/11/2014] [Indexed: 12/14/2022] Open
Abstract
Background We conducted a dose–response meta-analysis of prospective studies to summarize evidence of the association between tea consumption and the risk of breast, colorectal, liver, prostate, and stomach cancer. Methods We searched PubMed and two other databases. Prospective studies that reported risk ratios (RRs) with 95% confidence intervals (CIs) of cancer risk for ≥3 categories of tea consumption were included. We estimated an overall RR with 95% CI for an increase of three cups/day of tea consumption, and, usingrestricted cubic splines, we examined a nonlinear association between tea consumption and cancer risk. Results Forty-one prospective studies, with a total of 3,027,702 participants and 49,103 cancer cases, were included. From the pooled overall RRs, no inverse association between tea consumption and risk of five major cancers was observed. However, subgroup analysis showed that increase in consumption of three cups of black tea per day was a significant risk factor for breast cancer (RR, 1.18; 95% CI, 1.05-1.32). Conclusion Ourresults did not show a protective role of tea in five major cancers. Additional large prospective cohort studies are needed to make a convincing case for associations.
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Affiliation(s)
| | | | | | | | | | | | - Jia He
- Department of Health Statistics, Second Military Medical University, 800 Xiangyin Road, Shanghai 200433, China.
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Tea consumption and lung cancer risk: a meta-analysis of case-control and cohort studies. Nutrition 2014; 30:1122-7. [PMID: 25194612 DOI: 10.1016/j.nut.2014.02.023] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Revised: 02/20/2014] [Accepted: 02/25/2014] [Indexed: 12/30/2022]
Abstract
OBJECTIVE Recent epidemiologic studies, especially cohort and case-control studies, have yielded inconsistent findings regarding the association between tea consumption and risk for lung cancer. The aim of this study was to assess a potential relationship between tea consumption and the incidence of lung cancer worldwide. METHODS A systematic literature search of PubMed, Web of Science, the Cochrane Library, Google Scholar, the Chinese Biomedical Database, and Wanfang Database was conducted from 1966 to January 2014 by two investigators. All cohort studies and case-control studies that evaluated the association of tea and lung cancer were included. Summary relative risks (RR) and the corresponding 95% confidence intervals (CIs) were calculated using a random-effects model. Quality assessments were performed using the Newcastle-Ottawa Scale. Heterogeneity was assessed using the Q and I(2) tests, and the source of heterogeneity was detected by meta-regression analysis. Publication bias was evaluated with Egger's regression symmetry test. Subgroup analyses and sensitivity analysis were performed. RESULTS Thirty-eight lung cancer studies (26 case-control studies and 12 cohort studies) with 59,041 cases and 396,664 controls were included. Overall tea consumption was significantly associated with decreased risk for lung cancer (RR, 0.78; 95% CI, 0.70-0.87). Subgroup analyses showed that tea consumption was associated with reduced risk for lung cancer in women (RR, 0.76; 95% CI, 0.62-0.93), case-control studies (RR 0.72; 95% CI 0.63-0.83), Western studies (RR, 0.85; 95% CI, 0.75-0.97), and studies in China and Japan (RR, 0.74; 95% CI, 0.62-0.88). Both green tea (RR, 0.75; 95% CI, 0.62-0.91) and black tea (RR, 0.82; 95% CI, 0.71-0.94) were significantly associated with reduced lung cancer risk. No significant association was found in men or in cohort studies. CONCLUSION Tea consumption may offer some protection against lung cancer.
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Prospective study of the relationship between coffee and tea with colorectal cancer risk: the PLCO Cancer Screening Trial. Br J Cancer 2013; 109:1352-9. [PMID: 23907431 PMCID: PMC3778290 DOI: 10.1038/bjc.2013.434] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 07/01/2013] [Accepted: 07/04/2013] [Indexed: 12/18/2022] Open
Abstract
Background: Coffee and tea are commonly consumed and carry potential anticancer components that could reduce the risk of colorectal cancer; however, their relationships with colorectal cancer risk remain inconsistent. Methods: A prospective analysis was carried out to examine the relationships of coffee and tea intake with colorectal cancer risk in 57 398 men and women in the intervention arm of the National Cancer Institute-Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial, a national screening study that limits differential detection biases. Coffee and tea intakes were assessed by food frequency questionnaire. Results: Six hundred and eighty-one incident colorectal cancer cases were ascertained during a median follow-up of 11.4 years. Greater coffee intake was not associated with risk of colorectal cancer (relative risk (RR)=1.08, 95% confidence interval (CI)=0.79–1.48, Ptrend=0.23). Stratifying by cancer site (Pheterogeneity=0.48) or stage (Pheterogeneity=0.83) did not alter the relationship. Associations remained unchanged in subsets of participants for either caffeinated or decaffeinated coffee or when stratifying by several colorectal cancer risk factors. Similarly, greater tea intake was not associated with colorectal cancer risk overall (RR=0.77, 95% CI=0.55–1.09, Ptrend=0.17) or by cancer site (Pheterogeneity=0.14) or stage (Pheterogeneity=0.60). These associations were not modified by several colorectal cancer risk factors. Conclusion: The findings of this study do not provide evidence to suggest that drinking coffee or tea is beneficial in protecting against colorectal cancer.
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Abstract
SIGNIFICANCE Diet exerts a major influence on the risk for developing cancer and heart disease. Food factors such as flavonoids are alleged to protect cells from premature aging and disease by shielding DNA, proteins, and lipids from oxidative damage. RECENT ADVANCES Our work has focused on clarifying the effects of dietary components on cancer cell proliferation and tumor growth, discovering mechanisms to explain the effects, and identifying the specific molecular targets of these compounds. Our strategy for identifying specific molecular targets of phytochemicals involves the use of supercomputer technology combined with protein crystallography, molecular biology, and experimental laboratory verification. CRITICAL ISSUES One of the greatest challenges for scientists is to reduce the accumulation of distortion and half truths reported in the popular media regarding the health benefits of certain foods or food supplements. The use of these is not new, but interest has increased dramatically because of perceived health benefits that are presumably acquired without unpleasant side effects. Flavonoids are touted to exert many beneficial effects in vitro. However, whether they can produce these effects in vivo is disputed. FUTURE DIRECTIONS The World Health Organization indicates that one third of all cancer deaths are preventable and that diet is closely linked to prevention. Based on this idea and epidemiological findings, attention has centered on dietary phytochemicals as an effective intervention in cancer development. However, an unequivocal link between diet and cancer has not been established. Thus, identifying cancer preventive dietary agents with specific molecular targets is essential to move forward toward successful cancer prevention.
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Affiliation(s)
- Ann M Bode
- The Hormel Institute, University of Minnesota, Austin, MN 55912, USA
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Geybels MS, Verhage BAJ, Arts ICW, van Schooten FJ, Goldbohm RA, van den Brandt PA. Dietary flavonoid intake, black tea consumption, and risk of overall and advanced stage prostate cancer. Am J Epidemiol 2013; 177:1388-98. [PMID: 23722011 DOI: 10.1093/aje/kws419] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Flavonoids are natural antioxidants found in various foods, and a major source is black tea. Some experimental evidence indicates that flavonoids could prevent prostate cancer. We investigated the associations between flavonoid intake, black tea consumption, and prostate cancer risk in the Netherlands Cohort study, which includes 58,279 men who provided detailed baseline information on several cancer risk factors. From 1986 to 2003, 3,362 prostate cancers were identified, including 1,164 advanced (stage III/IV) cancers. Cox proportional hazards regression using the case-cohort approach was used to estimate hazard ratios and 95% confidence intervals. Intake of total catechin, epicatechin, kaempferol, and myricetin and consumption of black tea were associated with a decreased risk of stage III/IV or stage IV prostate cancer. Hazard ratios of stage III/IV and stage IV prostate cancer for the highest versus the lowest category of black tea consumption (≥5 versus ≤1 cups/day) were 0.75 (95% confidence interval: 0.59, 0.97) and 0.67 (95% confidence interval: 0.50, 0.91), respectively. No associations were observed for overall and nonadvanced prostate cancer. In conclusion, dietary flavonoid intake and black tea consumption were associated with a decreased risk of advanced stage prostate cancer.
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Affiliation(s)
- Milan S Geybels
- Department of Epidemiology, GROW School for Oncology and Developmental Biology,Maastricht University, Maastricht, the Netherlands.
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Wu Y, Zhang D, Kang S. Black tea, green tea and risk of breast cancer: an update. SPRINGERPLUS 2013; 2:240. [PMID: 23750333 PMCID: PMC3671100 DOI: 10.1186/2193-1801-2-240] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Accepted: 04/29/2013] [Indexed: 01/19/2023]
Abstract
Previous meta-analysis indicated conflicting results in case–control versus cohort studies on the association of green tea with breast cancer risk, and conflicting results were also found in case–control versus cohort studies in another meta-analysis on the association of black tea with breast cancer risk. Many studies were published after the previous meta-analysis. Besides, the dose-response relationship of tea consumption with breast cancer risk is unclear. Thus the association of tea consumption with breast cancer risk was assessed incorporating new publications. Summary relative risk (RR) for highest versus lowest level of tea consumption was calculated based on fixed or random effect models. Dose-response relationship was assessed by restricted cubic spline model and multivariate random-effect meta-regression. The combined results from 9 studies suggested no significant association between green tea consumption and breast cancer risk (RR = 0.82, 95% CI = 0.64-1.04). No significant association was found among cohort studies and case-control studies after sensitivity analysis, respectively. A linear but not significant dose-response association was found between green tea consumption and breast cancer risk. The combined results from 25 studies demonstrated no significant association between black tea consumption and breast cancer risk (RR = 0.98, 95% CI = 0.93-1.03), and no significant association was found in subgroup analysis. A linear but not significant dose-response association was found between black tea consumption and breast cancer risk. Based on the current evidence, black tea and green tea might not contribute significantly to breast cancer risk, respectively.
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Affiliation(s)
- Yili Wu
- Department of Epidemiology and Health Statistics, The Medical College of Qingdao University, Dongzhou Road, No.38, Shandong Qingdao, 266021 P. R. China
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Black tea in chemo-prevention of cancer and other human diseases. FOOD SCIENCE AND HUMAN WELLNESS 2013. [DOI: 10.1016/j.fshw.2013.03.004] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Wang Y, Yu X, Wu Y, Zhang D. Coffee and tea consumption and risk of lung cancer: A dose–response analysis of observational studies. Lung Cancer 2012; 78:169-70. [DOI: 10.1016/j.lungcan.2012.08.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2012] [Accepted: 08/15/2012] [Indexed: 11/16/2022]
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Abstract
BACKGROUND Flavonoids are polyphenolic compounds that are distributed widely in the plant kingdom; they are especially abundant in fruits and vegetables. More than 5,000 individual flavonoids have been identified and classified into more than 10 subgroups according to their chemical structure. Flavonoids have many possible biological effects that may play a role in cancer prevention. Prior studies have suggested that a high intake of flavonoids may help prevent cancer. OBJECTIVES To assess the effect of dietary flavonoids on the incidence of colorectal adenoma and CRC. SEARCH METHODS Eligible studies were searched up until July 2011 in the Cochrane Library, PubMed, EMBASE and other CINAHL databases and reference lists of previous reviews. SELECTION CRITERIA All prospective, controlled interventional studies and observational studies that either assessed the association between flavonoids and risk of CRC incidence or colorectal adenoma recurrence were included. DATA COLLECTION AND ANALYSIS At least two investigators independently reviewed the material and extracted the data according to the inclusion criteria; in addition, the methodological quality of the studies was assessed. MAIN RESULTS Eight studies with 390,769 participants were included. Five studies used a prospective cohort design, two were case-control studies and one a randomised controlled trial (RCT). The methodological quality was measured using the Newcastle-Ottawa scale (NOS). The three prospective cohort studies were of high methodological quality, and two were of medium quality. The two case-control studies were of medium methodological quality.The results form the studies assessing associations between flavonoids, colorectal cancer and adenomas were contradictory. There was no evidence that total flavonoid intake reduced the risk of colorectal neoplasms. The evidence for Isoflavones, Flavonols, Flavones and Flavanones was conflicting. For Flavan-3-ols, the results from two studies suggested that increased intake of Flavan-3-ols reduced the risk of both CRC and colorectal adenomas. A statistically significant reduced risk of CRC was found with high intake of epicatechin. There was medium quality evidence to support that increased intake of procyanidin and phytoestrogen could reduced the incidence of CRC. There was no evidence that suggested that high anthocyanin intake had an inverse association with colorectal adenomas. AUTHORS' CONCLUSIONS There is insufficient and conflicting evidence regarding flavonoid intake and the prevention of colorectal neoplasms. It is difficult to determine flavonoid intake. Therefore, more evidence is needed to clarify the association between flavonoids and colorectal neoplasms.
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Affiliation(s)
- Heiying Jin
- National Center of Colorectal Surgery, The 3rd affiliated Hospital of Nanjing University of Traditional Chinese Medicine, Nanjing, China.
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Sinha R, Cross AJ, Daniel CR, Graubard BI, Wu JW, Hollenbeck AR, Gunter MJ, Park Y, Freedman ND. Caffeinated and decaffeinated coffee and tea intakes and risk of colorectal cancer in a large prospective study. Am J Clin Nutr 2012; 96:374-81. [PMID: 22695871 PMCID: PMC3396445 DOI: 10.3945/ajcn.111.031328] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Coffee and tea are widely consumed globally and are rich sources of potential chemopreventive compounds. Epidemiologic data for coffee and tea intakes in relation to colorectal cancer remain unclear. Despite differences in gut physiology, few studies have conducted investigations by anatomic subsites. OBJECTIVE We evaluated coffee and tea intakes (caffeinated and decaffeinated) in relation to colon (proximal and distal) and rectal cancers. DESIGN The NIH-AARP Diet and Health Study included 489,706 men and women who completed a baseline (1995-1996) self-administered questionnaire of demographics, diet, and lifestyle. Over a median of 10.5 y of follow-up, we identified 2863 proximal colon, 1993 distal colon, and 1874 rectal cancers. Multivariable HRs and 95% CIs were estimated by using Cox regression. RESULTS Approximately 16% of participants drank ≥4 cups coffee/d. Compared with nondrinkers, drinkers of 4-5 cups coffee/d (HR: 0.85; 95% CI: 0.75, 0.96) and ≥6 cups coffee/d (HR: 0.74; 95% CI: 0.61, 0.89; P-trend < 0.001) had a lower risk of colon cancer, particularly of proximal tumors (HR for ≥6 cups/d: 0.62; 95% CI: 0.49, 0.81; P-trend < 0.0001). Results were similar to those overall for drinkers of predominantly caffeinated coffee. Although individual HRs were not significant, there was a significant P-trend for both colon and rectal cancers for people who drank predominantly decaffeinated coffee. No associations were observed for tea. CONCLUSIONS In this large US cohort, coffee was inversely associated with colon cancer, particularly proximal tumors. Additional investigations of coffee intake and its components in the prevention of colorectal cancer by subsites are warranted. The NIH-AARP Diet and Health Study was registered at clinicaltrials.gov as NCT00340015.
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Affiliation(s)
- Rashmi Sinha
- Nutritional Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Department of Health and Human Services, Rockville, MD, USA.
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Das L, Bhaumik E, Raychaudhuri U, Chakraborty R. Role of nutraceuticals in human health. JOURNAL OF FOOD SCIENCE AND TECHNOLOGY 2012; 49:173-83. [PMID: 23572839 PMCID: PMC3550857 DOI: 10.1007/s13197-011-0269-4] [Citation(s) in RCA: 226] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Revised: 04/14/2010] [Accepted: 07/06/2010] [Indexed: 12/25/2022]
Abstract
Nutraceutical is the hybrid of 'nutrition' and 'pharmaceutical'. Nutraceuticals, in broad, are food or part of food playing a significant role in modifying and maintaining normal physiological function that maintains healthy human beings. The principal reasons for the growth of the nutraceutical market worldwide are the current population and the health trends. The food products used as nutraceuticals can be categorized as dietary fibre, prebiotics, probiotics, polyunsaturated fatty acids, antioxidants and other different types of herbal/ natural foods. These nutraceuticals help in combating some of the major health problems of the century such as obesity, cardiovascular diseases, cancer, osteoporosis, arthritis, diabetes, cholesterol etc. In whole, 'nutraceutical' has lead to the new era of medicine and health, in which the food industry has become a research oriented sector.
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Affiliation(s)
- Lipi Das
- Department of Food Technology and Biochemical Engineering, Jadavpur University, Kolkata, 700032 India
| | - Eshani Bhaumik
- Department of Food Technology and Biochemical Engineering, Jadavpur University, Kolkata, 700032 India
| | - Utpal Raychaudhuri
- Department of Food Technology and Biochemical Engineering, Jadavpur University, Kolkata, 700032 India
| | - Runu Chakraborty
- Department of Food Technology and Biochemical Engineering, Jadavpur University, Kolkata, 700032 India
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Sasazuki S, Tamakoshi A, Matsuo K, Ito H, Wakai K, Nagata C, Mizoue T, Tanaka K, Tsuji I, Inoue M, Tsugane S. Green tea consumption and gastric cancer risk: an evaluation based on a systematic review of epidemiologic evidence among the Japanese population. Jpn J Clin Oncol 2012; 42:335-46. [PMID: 22371426 DOI: 10.1093/jjco/hys009] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
OBJECTIVE Numerous in vitro and animal studies have shown that green tea has a protective effect against cancer. However, results from epidemiologic studies are conflicting. We evaluated the association between green tea consumption and risk for gastric cancer risk among the Japanese population based on a systematic review of epidemiologic evidence. METHODS Original data were obtained from MEDLINE searches using PubMed or from searches of the Ichushi database, complemented with manual searches. Evaluation of associations was based on the strength of evidence and the magnitude of association, together with biologic plausibility. RESULTS Eight cohort studies and three case-control studies were identified. Overall, we found no preventive effect on gastric cancer for green tea intake in cohort studies. However, a small, consistent risk reduction limited to women was observed, which was confirmed by pooling data of six cohort studies (hazard ratio = 0.79, 95% confidence interval 0.65-0.96 with ≥5 cups/day of green tea intake). Case-control studies consistently showed a weak inverse association between green tea intake and gastric cancer risk. CONCLUSIONS We conclude that green tea possibly decreases the risk of gastric cancer in women. However, epidemiologic evidence is still insufficient to demonstrate any association in men.
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Affiliation(s)
- Shizuka Sasazuki
- Epidemiology and Prevention Division, Research Center for Cancer Prevention and Screening, National Cancer Center, 5-1-1 Tsukiji Chuo-ku, Tokyo 104-0045 Japan.
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Lung Cancer. Integr Med (Encinitas) 2012. [DOI: 10.1016/b978-1-4377-1793-8.00060-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Abstract
Experimental studies have consistently shown the inhibitory activities of tea extracts on tumorigenesis in multiple model systems. Epidemiological studies, however, have produced inconclusive results in humans. A comprehensive review was conducted to assess the current knowledge on tea consumption and risk of cancers in humans. In general, consumption of black tea was not associated with lower risk of cancer. High intake of green tea was consistently associated with reduced risk of upper gastrointestinal tract cancers after sufficient control for confounders. Limited data support a protective effect of green tea on lung and hepatocellular carcinogenesis. Although observational studies do not support a beneficial role of tea intake on prostate cancer risk, phase II clinical trials have demonstrated an inhibitory effect of green tea extract against the progression of prostate pre-malignant lesions. Green tea may exert beneficial effects against mammary carcinogenesis in premenopausal women and recurrence of breast cancer. There is no sufficient evidence that supports a protective role of tea intake on the development of cancers of the colorectum, pancreas, urinary tract, glioma, lymphoma, and leukemia. Future prospective observational studies with biomarkers of exposure and phase III clinical trials are required to provide definitive evidence for the hypothesized beneficial effect of tea consumption on cancer formation in humans.
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Affiliation(s)
- Jian-Min Yuan
- The Masonic Cancer Center, and Division of Epidemiology and Community Health, School of Public Health, University of Minnesota, 425 East River Road, 554 MCRB, Minneapolis, MN 55455, USA.
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No association between coffee, tea or caffeine consumption and breast cancer risk in a prospective cohort study. Public Health Nutr 2011; 14:1315-20. [PMID: 21466740 DOI: 10.1017/s1368980011000371] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Numerous mechanisms for the effects of coffee, tea and caffeine on the risk of breast cancer have been suggested. Caffeine intake has already been associated with high plasma levels of female hormones, but associations have not been clearly demonstrated in epidemiological studies. DESIGN We examined prospectively the association of coffee, tea and caffeine consumption with breast cancer risk in a French cohort study. SETTING Dietary information was obtained from a 208-item diet history questionnaire self-administered in 1993-1995. Multivariable Cox proportional hazards regression models were used to estimate hazards ratios and 95 % confidence intervals. SUBJECTS The study was conducted on 67 703 women with available dietary information. During a median follow-up of 11 years, 2868 breast cancer cases were diagnosed. RESULTS Median intake was 280 ml/d (2·2 cups/d) for coffee and 214 ml/d (1·7 cups/d) for tea. Median caffeine intake was 164 mg/d. No association was found between consumption of coffee, tea or caffeine and breast cancer risk. Sub-analyses by tumour receptor status, menopausal status, type of coffee (regular or decaffeinated) and meals at which beverages were drunk led to the same conclusion. CONCLUSIONS Results from this prospective study showed no relationship between coffee, tea or caffeine intake and breast cancer risk overall or by hormone receptor status.
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Chakrabarty S, Das A, Bhattacharya A, Chakrabarti G. Theaflavins depolymerize microtubule network through tubulin binding and cause apoptosis of cervical carcinoma HeLa cells. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2011; 59:2040-2048. [PMID: 21323312 DOI: 10.1021/jf104231b] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Here we studied the antiproliferative activity of theaflavins in cervical carcinoma HeLa cells by investigating their effects on cellular microtubules and purified goat brain tubulin. Theaflavins inhibited proliferation of HeLa cells with IC(50) value of 110 ± 2.1 μg/mL (p = < 0.01), caused cell cycle arrest at G(2)/M phase and induced apoptosis with alteration of expression of pro- and antiapoptotic proteins. Along with these antiproliferative activities, theaflavins act as microtubule depolymerizers. Theaflavins disrupted the microtubule network accompanied by alteration of cellular morphology and also decreased the polymeric tubulin mass of the cells. The polymerization of cold treated depolymerized microtubules in HeLa cells was prevented in the presence of theaflavins. In vitro polymerization of purified tubulin into microtubules was also inhibited by theaflavins with an IC(50) value of 78 ± 2.43 μg/mL (P < 0.01). Thus, disruption of cellular microtubule network of HeLa cells through microtubule depolymerization may be one of the possible mechanisms of antiproliferative activity of theaflavins.
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Affiliation(s)
- Subhendu Chakrabarty
- Department of Biotechnology and Dr. B. C. Guha Centre for Genetic Engineering and Biotechnology, University of Calcutta, 35 Ballygunge Circular Road, Kolkata, WB 700019, India
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Abstract
The incidence of nonmelanoma skin cancer is increasing every year. Basal cell carcinoma and squamous cell carcinoma are the two major types of nonmelanoma skin cancer. Among other factors, understanding the potential role of nutrients in the development, progression, and treatment of nonmelanoma skin cancer is critical. This contribution provides a review of the nutrients that have been more extensively investigated in the literature with regard to nonmelanoma skin cancer, including dietary fats, retinol, carotenoids, vitamin C, vitamin D, vitamin E, selenium, copper, iron, zinc, green tea, and black tea.
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Affiliation(s)
- Michael J Payette
- Department of Dermatology, MC-6230, University of Connecticut Health Center, 263 Farmington Avenue, Farmington, CT 06030, USA
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Abstract
Flavonoids are a large class of naturally occurring compounds widely present in fruits, vegetables and beverages derived from plants. These molecules have been reported to possess a wide range of activities in the prevention of common diseases, including CHD, cancer, neurodegenerative diseases, gastrointestinal disorders and others. The effects appear to be related to the various biological/pharmacological activities of flavonoids. A large number of publications suggest immunomodulatory and anti-inflammatory properties of these compounds. However, almost all studies are in vitro studies with limited research on animal models and scarce data from human studies. The majority of in vitro research has been carried out with single flavonoids, generally aglycones, at rather supraphysiological concentrations. Few studies have investigated the anti-inflammatory effects of physiologically attainable flavonoid concentrations in healthy subjects, and more epidemiological studies and prospective randomised trials are still required. This review summarises evidence for the effects of fruit and tea flavonoids and their metabolites in inflammation and immunity. Mechanisms of effect are discussed, including those on enzyme function and regulation of gene and protein expression. Animal work is included, and evidence from epidemiological studies and human intervention trials is reviewed. Biological relevance and functional benefits of the reported effects, such as resistance to infection or exercise performance, are also discussed.
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Gullett NP, Ruhul Amin ARM, Bayraktar S, Pezzuto JM, Shin DM, Khuri FR, Aggarwal BB, Surh YJ, Kucuk O. Cancer prevention with natural compounds. Semin Oncol 2010; 37:258-81. [PMID: 20709209 DOI: 10.1053/j.seminoncol.2010.06.014] [Citation(s) in RCA: 319] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Botanical and nutritional compounds have been used for the treatment of cancer throughout history. These compounds also may be useful in the prevention of cancer. Population studies suggest that a reduced risk of cancer is associated with high consumption of vegetables and fruits. Thus, the cancer chemopreventive potential of naturally occurring phytochemicals is of great interest. There are numerous reports of cancer chemopreventive activity of dietary botanicals, including cruciferous vegetables such as cabbage and broccoli, Allium vegetables such as garlic and onion, green tea, Citrus fruits, soybeans, tomatoes, berries, and ginger, as well as medicinal plants. Several lead compounds, such as genistein (from soybeans), lycopene (from tomatoes), brassinin (from cruciferous vegetables), sulforaphane (from asparagus), indole-3-carbinol (from broccoli), and resveratrol (from grapes and peanuts) are in preclinical or clinical trials for cancer chemoprevention. Phytochemicals have great potential in cancer prevention because of their safety, low cost, and oral bioavailability. In this review, we discuss potential natural cancer preventive compounds and their mechanisms of action.
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Affiliation(s)
- Norleena P Gullett
- Department of Radiation Oncology, Winship Cancer Institute, Emory University, Atlanta, GA 30322, USA
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Ekström AM, Serafini M, Nyrén O, Wolk A, Bosetti C, Bellocco R. Dietary quercetin intake and risk of gastric cancer: results from a population-based study in Sweden. Ann Oncol 2010; 22:438-43. [PMID: 20688844 DOI: 10.1093/annonc/mdq390] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND To study the impact of the dietary antioxidant quercetin on risk of gastric adenocarcinoma. PATIENTS AND METHODS Using data from a large Swedish population-based case-control study of gastric cancer (505 cases and 1116 controls), we studied the association between quercetin and risk of anatomic (cardia/noncardia) and histological (intestinal and diffuse) subtypes of gastric cancer. RESULTS We found strong inverse associations between quercetin and the risk of noncardia gastric adenocarcinoma, with an adjusted odds ratio (OR) of 0.57 (95% confidence interval 0.40-0.83) for the highest quintile (≥11.9 mg) of daily quercetin intake relative to the lowest quintile of intake (<4 mg quercetin/day), supported by a significant decreasing linear trend (P value < 0.001). Similar findings were observed for the intestinal and diffuse subtype. For cardia cancer, we found a less evident and nonsignificant inverse relationship. The protection of quercetin appeared to be stronger among female smokers, with the OR leveled of at values <0.2 in quintiles 3-5 (>6 mg quercetin/day). CONCLUSIONS High dietary quercetin intake is inversely related to the risk of noncardia gastric adenocarcinoma, and the protection appears to be particularly strong for women exposed to oxidative stress, such as tobacco smoking.
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Affiliation(s)
- A M Ekström
- Division of Global Health/IHCAR, Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden.
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Zhang X, Albanes D, Beeson WL, van den Brandt PA, Buring JE, Flood A, Freudenheim JL, Giovannucci EL, Goldbohm RA, Jaceldo-Siegl K, Jacobs EJ, Krogh V, Larsson SC, Marshall JR, McCullough ML, Miller AB, Robien K, Rohan TE, Schatzkin A, Sieri S, Spiegelman D, Virtamo J, Wolk A, Willett WC, Zhang SM, Smith-Warner SA. Risk of colon cancer and coffee, tea, and sugar-sweetened soft drink intake: pooled analysis of prospective cohort studies. J Natl Cancer Inst 2010; 102:771-83. [PMID: 20453203 PMCID: PMC2879415 DOI: 10.1093/jnci/djq107] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2009] [Revised: 03/08/2010] [Accepted: 03/09/2010] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND The relationships between coffee, tea, and sugar-sweetened carbonated soft drink consumption and colon cancer risk remain unresolved. METHODS We investigated prospectively the association between coffee, tea, and sugar-sweetened carbonated soft drink consumption and colon cancer risk in a pooled analysis of primary data from 13 cohort studies. Among 731 441 participants followed for up to 6-20 years, 5604 incident colon cancer case patients were identified. Study-specific relative risks (RRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models and then pooled using a random-effects model. All statistical tests were two-sided. RESULTS Compared with nonconsumers, the pooled multivariable relative risks were 1.07 (95% CI = 0.89 to 1.30, P(trend) = .68) for coffee consumption greater than 1400 g/d (about six 8-oz cups) and 1.28 (95% CI = 1.02 to 1.61, P(trend) = .01) for tea consumption greater than 900 g/d (about four 8-oz cups). For sugar-sweetened carbonated soft drink consumption, the pooled multivariable relative risk comparing consumption greater than 550 g/d (about 18 oz) to nonconsumers was 0.94 (95% CI = 0.66 to 1.32, P(trend) = .91). No statistically significant between-studies heterogeneity was observed for the highest category of each beverage consumed (P > .20). The observed associations did not differ by sex, smoking status, alcohol consumption, body mass index, physical activity, or tumor site (P > .05). CONCLUSIONS Drinking coffee or sugar-sweetened carbonated soft drinks was not associated with colon cancer risk. However, a modest positive association with higher tea consumption is possible and requires further study.
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Affiliation(s)
- Xuehong Zhang
- Department of Nutrition, Department of Epidemiology, Harvard School of Public Health, 655 Huntington Ave, Boston, MA 02115, USA.
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Abstract
Tea, next to water, is the most popular beverage in the world. It has been suggested that tea consumption has the cancer-preventive effects. Epidemiological studies have indicated decreased cancer occurrence in people who regularly drink green tea. Research has also discovered numerous mechanisms of action to explain the biological effects of tea. The most abundant and popular compound studied in tea research is (-)-epigallocatechin-3-gallate or (-)-EGCG, which is a powerful antioxidant and can inhibit a number of tumor cell proliferation and survival pathways. Tea polyphenols are known to inhibit metaloproteonases, various protein kinases, and proteins that regulate DNA replication and transformation. We also reported that ester bond-containing tea polyphenols, for example, (-)-EGCG, potently and specifically inhibited the tumor proteasomal activity. We further demonstrated that methylation on green tea polyphenols under physiological conditions decreased their proteasome-inhibitory activity, contributing to decreased cancer-preventive effects of tea consumption. Since (-)-EGCG is unstable under physiological conditions, we also developed the peracetate-protected or prodrug form of (-)-EGCG, Pro-EGCG (1), and showed that Pro-EGCG (1) increases the bioavailability, stability, and proteasome-inhibitory and anticancer activities of (-)-EGCG in human breast cancer cells and tumors, demonstrating its potential use for cancer prevention and treatment.
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Affiliation(s)
- Q Ping Dou
- Barbara Ann Karmanos Cancer Institute, Department of Pathology, School of Medicine, Wayne State University, Detroit, Michigan 48201, USA.
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N-acetyltransferase 2, exposure to aromatic and heterocyclic amines, and receptor-defined breast cancer. Eur J Cancer Prev 2010; 19:100-9. [PMID: 19996973 DOI: 10.1097/cej.0b013e328333fbb7] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The role of N-acetyltransferase 2 (NAT2) polymorphism in breast cancer is still unclear. We explored the associations between potential sources of exposure to aromatic and heterocyclic amines (AHA), acetylation status and receptor-defined breast cancer in 1020 incident cases and 1047 population controls of the German GENICA study. Acetylation status was assessed as slow or fast. Therefore, NAT2 haplotypes were estimated using genotype information from six NAT2 polymorphisms. Most probable haplotypes served as alleles for the deduction of NAT2 acetylation status. The risks of developing estrogen receptor alpha (ER) and progesterone receptor (PR)-positive or negative tumors were estimated for tobacco smoking, consumption of red meat, grilled food, coffee, and tea, as well as expert-rated occupational exposure to AHA with logistic regression conditional on age and adjusted for potential confounders. Joint effects of these factors and NAT2 acetylation status were investigated. Frequent consumption of grilled food and coffee showed higher risks in slow acetylators for receptor-negative tumors [grilled food: ER-: odds ratio (OR) 2.57, 95% confidence interval (CI) 1.07-6.14 for regular vs. rare; coffee: ER-: OR 2.55, 95% CI 1.22-5.33 for >or=4 vs. 0 cups/day]. We observed slightly higher risks for never smokers that are fast acetylators for receptor-positive tumors compared with slow acetylators (ER-: OR 1.32, 95% CI 1.00-1.73). Our results support differing risk patterns for receptor-defined breast cancer. However, the modifying role of NAT2 for receptor-defined breast cancer is difficult to interpret in the light of complex mixtures of exposure to AHA.
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Kim MJ, Kim HI, Chung J, Jeong TS, Park HR. (-)-Epigallocatechin-3-gallate (EGCG) increases the viability of serum-starved A549 cells through its effect on Akt. THE AMERICAN JOURNAL OF CHINESE MEDICINE 2009; 37:723-34. [PMID: 19655410 DOI: 10.1142/s0192415x09007193] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The effect of epigallocatechin gallate (EGCG) on cell survival was studied by using serum-starved A549 non-small cell lung carcinoma (NSCLC) cells. A MTT assay showed that EGCG significantly increased the viability of serum-starved A549 cells compared to the control cells, though EGCG at high concentration (approximately 300 microM) had no protective effect against serum withdrawal-induced cell apoptosis. Western blots showed increased immunoreactivity for phospho-Akt and phospho-GSK3beta in EGCG-treated cells. To determine the mechanism for Akt phosphorylation, cells were pretreated with various kinase inhibitors before exposure to EGCG. Only LY294002 inhibited Akt activation induced by EGCG, implying that EGCG-induced Akt activation is PI3K dependent. Both phospho-Raf-1 and Raf-1 proteins were significantly decreased, whereas B-raf expression was not altered. This suggests that the Raf kinases have no role in the increased cell survival caused by EGCG. This study has shown that EGCG protects A549 cells from apoptosis induced by serum deprivation via Akt activation and this protective effect may limit the clinical use of EGCG in treating and preventing NSCLC.
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Affiliation(s)
- Myung Jin Kim
- Department of Oral Pathology, Pusan National University, Yang San, South Korea
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Pourfarzi F, Whelan A, Kaldor J, Malekzadeh R. The role of diet and other environmental factors in the causation of gastric cancer in Iran--a population based study. Int J Cancer 2009; 125:1953-1960. [PMID: 19569234 DOI: 10.1002/ijc.24499] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Despite a declining trend in the incidence of gastric cancer (GC), it is still a major global public health concern of the 21st century. The rates of GC reported from Ardabil Province, Iran, are among the highest in the world. To investigate risk factors for GC in Ardabil, we undertook a population-based case-control study. The study aimed to recruit all Ardabil residents newly diagnosed with GC in the time period of 2004-2005, and 2 controls per case. Participants were interviewed using a structured questionnaire. Ten milliliters of blood was collected for blood grouping and investigating the presence of IgG antibodies against Helicobacter pylori. During the study period, 217 people with GC and 394 controls were recruited. In multivariate analysis, diet and Helicobacter pylori infection (OR = 2.41; 95% CI: 1.35-4.32) were found to be the factors that were most strongly related to GC. High intake of Allium vegetables (OR = 0.35) and fruit, especially citrus fruit (OR = 0.31) and consumption of fresh fish (OR = 0.37) were significantly protective. On the other hand, consumption of red meat (OR = 3.40) and dairy products (OR = 2.28) were positively associated with the risk of GC. People who had a preference for higher salt intake (OR = 3.10) and drinking strong and hot tea (OR = 2.64 and 2.85, respectively) were at higher risk. In conclusion, Helicobacter pylori infection as measured by serum IgG as well as the consumption of red meat and dairy products increases the risk of GC in Ardabil, while the intake of fresh fruit and fresh fish decrease the risk.
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Affiliation(s)
- Farhad Pourfarzi
- Division of Community Medicine, Ardabil University of Medical Science, Ardabil, Iran.
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Abstract
India, with a population of over a billion is likely to increase global concern on cancer, particularly that of head and neck. The increasing immigration of Indians is likely to influence other parts of the world and an analysis of cancer-related practices could serve as a model for defining cancer-prevention strategies across the globe. The objective of this study was to review the anti- and pro-carcinogenic practices in India pertaining to head and neck cancer. The published literature on practices, compounds/chemicals/crude reparations related to the head and neck cancer in India was retrieved for analysis, while unauthentic or local information was discarded. The anti-carcinogenic practices prevalent in India consisted of classically varied diet being predominantly vegetarian, along with spices, condiments, beverages etc. The pro-carcinogenic practices predominantly include all shades of alcoholism and tobacco intake. Moreover, the diverse culture of the country reflects unique regional practices. The enormous diversity in practices related to head and neck cancer in India is very unique and interesting. Cancer prevention strategies need to focus on these trends to define a better global prevention.
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Affiliation(s)
- A Mishra
- C.S.M. Medical University (King George Medical College), A-1/19, Sector H, Aliganj, Lucknow, UP, India.
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Bissonauth V, Shatenstein B, Fafard E, Maugard C, Robidoux A, Narod S, Ghadirian P. Risk of Breast Cancer Among French-Canadian Women, Noncarriers of More FrequentBRCA1/2Mutations and Consumption of Total Energy, Coffee, and Alcohol. Breast J 2009; 15 Suppl 1:S63-71. [DOI: 10.1111/j.1524-4741.2009.00806.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abstract
Tea is the most widely used ancient beverage in the world and black tea possesses many biological effects on the organisms. It acts as an effective antioxidant because of its free radical-scavenging and metal-chelating ability. Due to this, it is active against inflammation, clastogenesis, and several types of cancer. Tea reduces DNA damage and mutagenesis due to oxidative stress or the presence of pro-mutagens through antioxidant function, blocking activation pathways of mutagens, suppressing transcription of enzymes involved etc. Inhibition of low-density lipoprotein (LDL) peroxidation, suppression of fatty acid synthase etc., suggest that tea may have a role in preventing cardiovascular diseases. Some epidemiological studies support the protective role of black tea against cardiovascular diseases but some do not. Besides, black tea has beneficial effects on the gastrointestinal tract; it affects motility, absorption, microflora etc., by influencing the hormonal balance and antioxidant function black tea improves bone mineral density. It is also antiviral due to its enzyme-inhibiting and receptor-blocking properties. Although its role in cancers of the gastrointestinal tract, liver, and prostate is confirmed, its effect against urinary tract cancer is uncertain and further studies are required. Apart from these, excess consumption may lead to the formation of a stained pellicle layer on teeth, which is difficult to eliminate, inhibits trypsin, influences mineral absorption, causes convulsions etc. Excess caffeine intake may have adverse effects on selected organs as reported in studies on some organisms. These reports indicate that there is a wide scope of further research for the efficient use of black tea active conserves/isolates to reap health benefits.
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Affiliation(s)
- Vasundhara Sharma
- Plantation Products, Spices and Flavour Technology Department, Central Food Technological Research Institute, Mysore, India
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Gallus S, Tramacere I, Tavani A, Bosetti C, Bertuccio P, Negri E, La Vecchia C. Coffee, black tea and risk of gastric cancer. Cancer Causes Control 2009; 20:1303-8. [PMID: 19430969 DOI: 10.1007/s10552-009-9350-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2009] [Accepted: 04/14/2009] [Indexed: 01/26/2023]
Abstract
BACKGROUND To provide information about the association of coffee, black tea with gastric cancer risk. METHODS Between 1985 and 2007, we conducted two case-control studies in northern Italy. Overall, cases were 999 subjects with incident, histologically confirmed gastric cancer and controls were 2,628 patients admitted to the same network of hospitals for acute non-neoplastic diseases. Odds ratios (OR) and the corresponding 95% confidence intervals (CI) for coffee (mostly espresso and mocha) and black tea consumption were estimated after allowance for socio-demographic data, smoking, and other major covariates of interest. RESULTS When compared with non-coffee drinkers, the OR was 0.94 (95% CI: 0.73-1.22) for drinkers of one cup of coffee per day, 1.03 (95% CI: 0.80-1.32) for two, 1.07 (95% CI: 0.82-1.40) for three, and 1.24 (95% CI: 0.94-1.65) for four or more cups per day. No association was found with reference to duration of coffee consumption, or consumption of decaffeinated coffee. When compared with non-black-tea drinkers, the OR was 0.89 (95% CI: 0.56-1.42) for drinkers of two or more cups of black tea per day. CONCLUSIONS Our investigation, based on a uniquely large dataset, provides convincing evidence that coffee and black tea consumption is unlikely to be strongly associated with gastric cancer risk.
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Affiliation(s)
- Silvano Gallus
- Istituto di Ricerche Farmacologiche Mario Negri, Via Giuseppe La Masa 19, 20156, Milan, Italy.
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Wang L, Lee IM, Zhang SM, Blumberg JB, Buring JE, Sesso HD. Dietary intake of selected flavonols, flavones, and flavonoid-rich foods and risk of cancer in middle-aged and older women. Am J Clin Nutr 2009; 89:905-12. [PMID: 19158208 PMCID: PMC2667658 DOI: 10.3945/ajcn.2008.26913] [Citation(s) in RCA: 197] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND Flavonoids may protect against cancer development through several biological mechanisms. However, epidemiologic studies on dietary flavonoids and cancer risk have yielded inconsistent results. OBJECTIVE We prospectively investigated the association between the intake of selected flavonoids and flavonoid-rich foods and risk of cancers in the Women's Health Study. DESIGN A total of 3234 incident cancer cases were identified during 11.5 y of follow-up among 38,408 women aged > or = 45 y. Intake of individual flavonols (quercetin, kaempferol, and myricetin) and flavones (apigenin and luteolin) was assessed from food-frequency questionnaires. Cox regression models were used to estimate the relative risk (RR) of total and site-specific cancer across increasing intakes of total and individual selected flavonoids and flavonoid-rich foods (tea, apple, broccoli, onion, and tofu). RESULTS The multivariate RRs of total cancer across increasing quintiles of total quantified flavonoid intake were 1.00, 1.00, 0.93, 0.94, and 0.97 (P for trend = 0.72). For site-specific cancers, the multivariate RRs in the highest quintile of total quantified flavonoid intake compared with the lowest quintile were 1.03 for breast cancer, 1.01 for colorectal cancer, 1.03 for lung cancer, 1.15 for endometrial cancer, and 1.09 for ovarian cancer (all P > 0.05). The associations for the individual flavonoid intakes were similar to those for the total intake. There was also no significant association between intake of flavonoid-rich foods and the incidence of total and site-specific cancers. CONCLUSION Our results do not support a major role of 5 common flavonols and flavones or selected flavonoid-rich foods in cancer prevention.
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Affiliation(s)
- Lu Wang
- Division of Preventive Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, MA 02215, USA.
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Shrubsole MJ, Lu W, Chen Z, Shu XO, Zheng Y, Dai Q, Cai Q, Gu K, Ruan ZX, Gao YT, Zheng W. Drinking green tea modestly reduces breast cancer risk. J Nutr 2009; 139:310-6. [PMID: 19074205 PMCID: PMC2646205 DOI: 10.3945/jn.108.098699] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2008] [Revised: 09/09/2008] [Accepted: 11/03/2008] [Indexed: 12/11/2022] Open
Abstract
Green tea is a commonly consumed beverage in China. Epidemiological and animal data suggest tea and tea polyphenols may be preventive against various cancers, including breast cancer. Catechol-O-methyltransferase (COMT) catalyzes catechol estrogens and tea polyphenols. The COMT rs4680 AA genotype leads to lower COMT activity, which may affect the relationship between green tea consumption and breast cancer risk. We evaluated whether regular green tea consumption was associated with breast cancer risk among 3454 incident cases and 3474 controls aged 20-74 y in a population-based case-control study conducted in Shanghai, China during 1996-2005. All participants were interviewed in person about green tea consumption habits, including age of initiation, duration of use, brew strength, and quantity of tea. Odds ratios (OR) and 95% CI were calculated for green tea consumption measures and adjusted for age and other confounding factors. Compared with nondrinkers, regular drinking of green tea was associated with a slightly decreased risk for breast cancer (OR, 0.88; 95% CI, 0.79-0.98). Among premenopausal women, reduced risk was observed for years of green tea drinking (P-trend = 0.02) and a dose-response relationship with the amount of tea consumed per month was also observed (P-trend = 0.046). COMT rs4680 genotypes did not have a modifying effect on the association of green tea intake with breast cancer risk. Drinking green tea may be weakly associated with a decreased risk of breast cancer.
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Affiliation(s)
- Martha J Shrubsole
- Department of Medicine, Vanderbilt Epidemiology Center, Vanderbilt School of Medicine, Nashville, TN 37232, USA
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Tang N, Wu Y, Zhou B, Wang B, Yu R. Green tea, black tea consumption and risk of lung cancer: a meta-analysis. Lung Cancer 2009; 65:274-83. [PMID: 19128856 DOI: 10.1016/j.lungcan.2008.12.002] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2008] [Revised: 12/01/2008] [Accepted: 12/01/2008] [Indexed: 02/07/2023]
Abstract
Studies investigating the association of green tea and black tea consumption with lung cancer risk have reported inconsistent findings. To provide a quantitative assessment of this association, we conducted a meta-analysis on the topic. Studies were identified by a literature search in PubMed from 1966 to November 2008 and by searching the reference lists of relevant studies. Summary relative risk (RR) estimates and their corresponding 95% confidence intervals (CIs) were calculated based on random-effects model. Our meta-analysis included 22 studies provided data on consumption of green tea or black tea, or both related to lung cancer risk. For green tea, the summary RR indicated a borderline significant association between highest green tea consumption and reduced risk of lung cancer (RR=0.78, 95% CI=0.61-1.00). Furthermore, an increase in green tea consumption of two cups/day was associated with an 18% decreased risk of developing lung cancer (RR=0.82, 95% CI=0.71-0.96). For black tea, no statistically significant association was observe through the meta-analysis (highest versus non/lowest, RR=0.86, 95% CI=0.70-1.05; an increment of two cups/day, RR=0.82, 95% CI=0.65-1.03). In conclusion, our data suggest that high or an increase in consumption of green tea but not black tea may be related to the reduction of lung cancer risk.
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Affiliation(s)
- Naping Tang
- National Shanghai Center for New Drug Safety Evaluation and Research, Shanghai Institute of Pharmaceutical Industry, Zhangjiang Hi-Tech Park, Pudong, Shanghai, China.
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Kumar N, Titus-Ernstoff L, Newcomb PA, Trentham-Dietz A, Anic G, Egan KM. Tea consumption and risk of breast cancer. Cancer Epidemiol Biomarkers Prev 2009; 18:341-5. [PMID: 19124518 PMCID: PMC3156033 DOI: 10.1158/1055-9965.epi-08-0819] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
OBJECTIVE The purpose of our study was to examine the association of regular tea consumption with the risk of breast cancer in a large population-based case-control study from the United States. METHODS Five thousand and eighty-two women with incident breast cancer between the ages of 20 and 74 years old from population-based cancer registries in Wisconsin, Massachusetts, and New Hampshire and 4,501 age-matched controls from lists of licensed drivers and Medicare beneficiaries completed a structured telephone interview that included information on usual tea consumption 5 years prior to the interview and other breast cancer risk factors. Logistic regression was used to obtain covariate-adjusted odds ratios and 95% confidence intervals associated with quantities of tea consumed. RESULTS Tea consumption was not related to breast cancer risk overall (P for trend = 0.18). However, when stratified by age, an inverse association was observed among women less than 50 years: those consuming three or more cups per day had a 37% reduced breast cancer risk when compared with women reporting no tea consumption (age and study site-adjusted odds ratios, 0.63; 95% confidence intervals, 0.44-0.89; P = 0.01) with a significant test for trend (P = 0.01). The inverse association noted among younger women was consistent for in situ and invasive breast cancer, and for ductal and lobular breast cancer. All results were unchanged after adjustment for established risk factors. CONCLUSION We observed evidence to support a potential beneficial influence for breast cancer associated with moderate levels of tea consumption (three or more cups per day) among younger women. Further research is needed to confirm this association.
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Affiliation(s)
- Nagi Kumar
- Department of Health Outcomes and Behavior, Population Sciences Division, Moffitt Cancer Center, 12902 Magnolia Drive, MRC/CANCONT, Tampa, FL 33612, USA.
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Ishitani K, Lin J, Manson JE, Buring JE, Zhang SM. Caffeine consumption and the risk of breast cancer in a large prospective cohort of women. ARCHIVES OF INTERNAL MEDICINE 2008; 168:2022-31. [PMID: 18852405 PMCID: PMC2574428 DOI: 10.1001/archinte.168.18.2022] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Prospective data relating caffeine consumption to breast cancer risk are limited. METHODS We evaluated the association between caffeine consumption and breast cancer risk in women enrolled in a completed cancer prevention trial. Detailed dietary information was obtained at baseline (1992-1995) from 38 432 women 45 years or older and free of cancer. During a mean follow-up of 10 years, we identified 1188 invasive breast cancer cases. RESULTS Consumption of caffeine and caffeinated beverages and foods was not statistically significantly associated with overall risk of breast cancer. The multivariate relative risks (RRs) of breast cancer were 1.02 (95% confidence interval [CI], 0.84-1.22) for caffeine (top vs bottom quintile), 1.08 (0.89-1.30) for coffee (> or =4 cups daily vs almost never), and 1.03 (0.85-1.25) for tea (> or =2 cups daily vs almost never). However, in women with benign breast disease, a borderline significant positive association with breast cancer risk was observed for the highest quintile of caffeine consumption (RR, 1.32; 95% CI, 0.99-1.76) and for the highest category of coffee consumption (> or =4 cups daily) (1.35; 1.01-1.80); tests for interaction were marginally significant. Caffeine consumption was also significantly positively associated with risk of estrogen receptor-negative and progesterone receptor-negative breast cancer (RR, 1.68; 95% CI, 1.01-2.81) and breast tumors larger than 2 cm (1.79; 1.18-2.72). CONCLUSIONS These data show no overall association between caffeine consumption and breast cancer risk. The possibility of increased risk in women with benign breast disease or for tumors that are estrogen and progesterone receptor negative or larger than 2 cm warrants further study.
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Affiliation(s)
- Ken Ishitani
- Division of Preventive Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02215, USA
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