Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Diabetes. Oct 25, 2015; 6(14): 1274-1284
Published online Oct 25, 2015. doi: 10.4239/wjd.v6.i14.1274
Whey protein: The “whey” forward for treatment of type 2 diabetes?
Linda E Mignone, Tongzhi Wu, Michael Horowitz, Christopher K Rayner
Linda E Mignone, Tongzhi Wu, Michael Horowitz, Christopher K Rayner, Discipline of Medicine, the University of Adelaide, Adelaide 5000, Australia
Linda E Mignone, Tongzhi Wu, Michael Horowitz, Christopher K Rayner, Centre of Research Excellence in Translating Nutritional Science to Good Health, the University of Adelaide, Adelaide 5000, Australia
Author contributions: Mignone LE drafted the manuscript; Wu T, Horowitz M and Rayner CK reviewed and edited the manuscript.
Supported by Royal Adelaide Hospital Dawes Scholarship (Mignone LE), Royal Adelaide Hospital Research Committee Early Career Fellowship (Wu T), and National Health and Medical Research Council funding (No. APP1066835).
Conflict-of-interest statement: The authors declare no conflict of interests for this article.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Correspondence to: Christopher K Rayner, MBBS, PhD, Professor, Discipline of Medicine, the University of Adelaide, Frome Road Adelaide, Adelaide 5000, Australia.
Telephone: +61-8-82222916 Fax: +61-8-82233870
Received: June 15, 2015
Peer-review started: June 17, 2015
First decision: July 27, 2015
Revised: August 21, 2015
Accepted: October 16, 2015
Article in press: October 19, 2015
Published online: October 25, 2015

A cost-effective nutritional approach to improve postprandial glycaemia is attractive considering the rising burden of diabetes throughout the world. Whey protein, a by-product of the cheese-making process, can be used to manipulate gut function in order to slow gastric emptying and stimulate incretin hormone secretion, thereby attenuating postprandial glycaemic excursions. The function of the gastrointestinal tract plays a pivotal role in glucose homeostasis, particularly during the postprandial period, and this review will discuss the mechanisms by which whey protein slows gastric emptying and stimulates release of gut peptides, including the incretins. Whey protein is also a rich source of amino acids, and these can directly stimulate beta cells to secrete insulin, which contributes to the reduction in postprandial glycaemia. Appetite is suppressed with consumption of whey, due to its effects on the gut-brain axis and the hypothalamus. These properties of whey protein suggest its potential in the management of type 2 diabetes. However, the optimal dose and timing of whey protein ingestion are yet to be defined, and studies are required to examine the long-term benefits of whey consumption for overall glycaemic control.

Keywords: Whey protein, Postprandial glycaemia, Type 2 diabetes, Dietary intervention, Preload, Gastric emptying, Incretins, Gut hormones, Appetite, Amino acids

Core tip: Whey protein, a by-product of cheese-manufacture, shows promise in the dietary management of diabetes. Whey can slow gastric emptying, stimulate insulin and gut hormones including the incretins, and thereby reduce postprandial blood glucose, especially when consumed some minutes before a meal. Whey may also suppress appetite and reduce food intake. This review will summarise these properties of whey and examine what further evidence is needed before whey can be recommended in the management of type 2 diabetes.