Published online Apr 14, 2017. doi: 10.3748/wjg.v23.i14.2527
Peer-review started: November 18, 2016
First decision: January 10, 2017
Revised: February 20, 2017
Accepted: March 20, 2017
Article in press: March 20, 2017
Published online: April 14, 2017
To investigate the relationship between the colors of vegetables and fruits and the risk of colorectal cancer in Korea.
A case-control study was conducted with 923 colorectal cancer patients and 1846 controls recruited from the National Cancer Center in Korea. We classified vegetables and fruits into four groups according to the color of their edible parts (e.g., green, orange/yellow, red/purple and white). Vegetable and fruit intake level was classified by sex-specific tertile of the control group. Logistic regression models were used for estimating the odds ratios (OR) and their 95% confidence intervals (CI).
High total intake of vegetables and fruits was strongly associated with a reduced risk of colorectal cancer in women (OR = 0.32, 95%CI: 0.21-0.48 for highest vs lowest tertile) and a similar inverse association was observed for men (OR = 0.60, 95%CI: 0.45-0.79). In the analysis of color groups, adjusted ORs (95%CI) comparing the highest to the lowest of the vegetables and fruits intake were 0.49 (0.36-0.65) for green, and 0.47 (0.35-0.63) for white vegetables and fruits in men. An inverse association was also found in women for green, red/purple and white vegetables and fruits. However, in men, orange/yellow vegetables and fruits (citrus fruits, carrot, pumpkin, peach, persimmon, ginger) intake was linked to an increased risk of colorectal cancer (OR = 1.61, 95%CI: 1.22-2.12).
Vegetables and fruits intake from various color groups may protect against colorectal cancer.
Core tip: Although many studies have focused on the associations between vegetable and fruit intake and health, few studies have classified vegetables and fruits by their colors, which reflect their unique contents of phytochemicals and micronutrients. In the current study, most color groups of vegetables and fruits showed protective benefits against colorectal cancer regardless of the anatomical subsites.