Whey protein is one of the two major proteins found in milk and dairy products. The other major protein in dairy products is casein—many people have sensitivities to casein, but few people seem to have any sensitivity to whey protein. When rennin, a protein that curdles milk, is added to milk and other dairy products, the curds (casein) and whey separate, just as they did in the old nursery rhyme.
Whey protein is used for a number of purposes—it is used to maintain daily protein intakes, to build muscle mass, and to increase fat loss. Whey isn’t the only protein to increase fat loss—most proteins do, but most proteins aren’t available in an easily dissolved powder as whey is.
Whey Protein, Insulin and Blood Sugar
There are a number of properties of whey protein that appear to be useful in diabetes. 
- Whey protein is a good source of the amino acid L-cysteine. L-cysteine is used to synthesize glutathione, one of the body’s most important antioxidant. Oxidative stress—the buildup of damaging free radicals—is thought to be one of the underlying causes of insulin resistance and to be responsible for some of the complications of diabetes such as peripheral neuropathy, retinopathy and kidney damage.
- Whey protein, when added to a meal, also appears to increase insulin secretion and to decrease blood sugar after a meal. (Post-prandial blood glucose)
- Whey protein can also decrease triglyceride levels in diabetics after meals.
In a recent study, blood sugar levels were 28% lower in those who had whey protein along with their meal. Insulin levels were increased (doubled) and, importantly, the insulin response lasted longer. The study was small, only examining the responses of 15 individuals, but the design of the study made the results significant.
Whey has other advantages – whey tends to make you feel more full for longer periods of time—this can help in weight loss programs. Whey protein also has anti-inflammatory activity—this can be very important in overall health and because inflammation is present in anyone with diabetes—and inflammation can make controlling blood sugar levels and weight loss tougher. Finally, whey protein appears to increase the loss of fat from the liver.
Overall, using whey protein can be a useful tool for anyone with diabetes trying to control their blood sugar. The decreases in blood sugar were significant but they won’t occur under all conditions. Much will depend what is included in the meal. However, the decreases in blood sugar are real and combined with following dietary guidelines and exercise guidelines, whey protein can help individuals with diabetes maintain their blood sugar control.
Whey protein is a component of human breast milk and I included in many infant formulas. Whey is considered safe when used in recommended amounts in adults, children and pregnant women.
How to Use Whey Protein
For most people, a reasonable amount of whey protein is 0.36g for every pound of body weight or 0.8g for every kilogram of body weight. You can have a whey smoothie for breakfast, sprinkle whey protein over cereal, and sprinkle whey powder into soups, stews and stir fries. Whey protein on its own can be bitter—there are a number of flavor choices, but you can also add spices such as vanilla, cinnamon or nutmeg and add stevia for non-sugary non-caloric sweetness.
Is whey protein good for diabetes?
- Whey protein appears to be a useful tool in helping to control blood sugar levels in diabetes and to potentially increase the secretion of insulin.
Is whey protein safe for diabetes?
- Whey protein appears to be safe for adults, children and pregnant women following the recommendations given here and from the manufacturers. Always let your physician and healthcare team know that you are considering adding whey protein to your diet plant.
Can Diabetics Use Whey Protein Shakes?
- Yes, people with diabetes can use whey protein as a protein shake, a beverage or added to foods in the recommended amounts.