The study, published in the journal Diabetologia, saw 15 individuals with well-controlled type 2 diabetes taking either 50 grams of whey in 250 ml of water or a placebo of just 250 ml of water on two separate days. This was followed by a high-glycemic index breakfast of three slices of white bread and sugary jelly – designed to create a post-meal glucose spike.
“The results showed that over the whole 180 min post-meal period, glucose levels were reduced by 28%, after whey pre-load with a uniform reduction driving both early and late phases,” the Lund University, Tel Aviv University and University of Jerusalem researchers wrote.
They said insulin and C-peptide responses were significantly higher than the control group at 105% and 43%, respectively. Meanwhile early insulin response was 96% higher after whey.
Professor Jakubowicz, one of the study’s authors, said: "The early insulin response that usually is deficient in type-2 diabetes was significantly higher after whey protein than with placebo, and the whey protein preload significantly reduced the elevation of blood glucose after breakfast.”
Adding: "Whey protein could therefore represent a novel approach for enhancing glucose-lowering strategies in type 2 diabetes."
Breakfast in hospital
Across the two groups, decided with the flick of a coin, blood samples assessing plasma concentration of glucose, intact GLP-1 (glucagon-like peptide), and insulin concentrations were taken. This was done 30 minutes before the high GI breakfast as the whey protein or placebo drinks were consumed as well as when the meal was served and then at 15, 30, 60, 90, 120, 150 and 180 minute intervals following breakfast.
The only medication the diabetic participants were taking was sulfonylurea and metformin.
Professor Jakubowicz said: “What's remarkable is that consuming whey protein before meals reduces the blood sugar spikes seen after meals. It also improves the body's insulin response, putting it in the same range or even higher than that produced by novel anti-diabetic drugs."
"High milk intake has long been associated with lower risk for type 2 diabetes and cardiovascular disease, and milk whey protein increases the production of a gut hormone called glucagon-like peptide-1 (GLP-1) that stimulates insulin secretion. This, in turn, reduces the blood glucose rise after meals."
The Israeli Ministry of Health and the Milk Council funded this first research round. The researchers said they were now considering a more long-term clinical trial on whey protein consumption for diabetics.
Vol. 57, Iss. 9, pp. 1807–1811, doi:10.1007/s00125-014-3305-x
“Incretin, insulinotropic and glucose-lowering effects of whey protein pre-load in type 2 diabetes: a randomised clinical trial”
Authors: D. Jakubowicz, O. Froy, B. Ahrén, M. Boaz, Z. Landau, Y. Bar-Dayan, T. Ganz, M. Barnea, J. Wainstein