October 30, 2014
The Dairy-Diabetes Debate

The Dairy-Diabetes Debate

by Berkeley Wellness  |  

Nonfat (skim) milk is healthier than whole milk, right? Well, not according to TV’s Dr. Oz and some other purveyors of health advice. They’ve warned that removing the fat from milk leaves too high a concentration of natural sugars, and that this can play havoc with the body’s insulin response. The implication is that nonfat milk can thus raise your risk of diabetes, obesity, and other chronic diseases.

It’s true that any sugar-loaded food can boost insulin levels. As foods are digested, sugar (glucose) enters the bloodstream, triggering the pancreas to release insulin, a hormone that “pushes” the sugar into cells where it’s used for energy. One concern, at least in theory, is that chronic consumption of insulin-boosting foods will overstimulate pancreatic cells, eventually leading to their death, as seen in diabetes.

But the demonizing of nonfat milk is nonsense. It has no more sugar (lactose) than whole milk. Moreover, the regulation of blood sugar and insulin in the body is complex. How much a food raises them depends on other factors besides the food’s sugar content. Other components of food, notably the protein in dairy, play a role. So does how much you consume and what else you eat. For example, nonfat milk with cereal has a different effect on blood sugar and insulin than the milk alone.

When it comes to diabetes, numerous studies actually find benefits, not risks, from low-fat and nonfat dairy. A 2011 study published in the Journal of Nutrition of more than 80,000 postmenopausal women, for instance, found that those who ate about three servings of low-fat dairy foods a day, including nonfat milk, were about 40 percent less likely to develop diabetes over the course of eight years than those eating little or none.

Similarly, a large study published in the Archives of Internal Medicine linked low-fat and nonfat dairy consumption to reduced diabetes risk in men. It’s not clear what may account for the diabetes protection, but researchers propose that the lactose and protein in dairy may promote satiety and thus help reduce obesity, while milk protein may additionally improve insulin sensitivity, all of which decrease the risk of diabetes.

The blame game

Cow’s milk has been blamed for everything from excess mucus production to heart disease and cancer. It’s not surprising that critics are now picking on nonfat milk, too. Arguments against milk are often highly politicized, with the dairy industry on one side and milk opponents on the other. But the body of evidence, which includes plenty of well-designed studies from both the dairy industry and independent researchers, supports few, if any, anti-milk claims.

Bottom line: Dairy products are very nutritious and the chief source of calcium in the American diet. High in potassium, they are a big component of the DASH diet, which is designed to control blood pressure. The dairy debate will undoubtedly continue, but future research should resolve any lingering concerns. In the meantime, we think you should continue to enjoy nonfat and low-fat dairy foods, including nonfat milk, as part of a heart-healthy low-saturated-fat diet. At the very least, choosing nonfat/low-fat over whole milk sources saves substantial calories. If you don’t like milk—or are lactose intolerant—you can get the nutrients you need from other sources.