A natural substance in dairy fat may dramatically reduce the risk of Type 2 diabetes, according to a new observational study from the Harvard School of Public Health. There are currently 24 million people in the United States with Type 2 diabetes and another 57 million with prediabetes who are at risk of progressing to Type 2.
The substance, known as trans-palmitoleic acid, is a fatty acid that is found in milk, cheese, yogurt, and butter. It is not produced by the human body and therefore can only be obtained in the diet. To determine whether levels of trans-palmitoleic acid in the bloodstream are related to a lower risk of Type 2 diabetes, the researchers examined data from 3,376 adults who had been followed for 20 years as part of the Cardiovascular Health Study. Metabolic factors such as blood glucose and insulin levels, and levels of blood fatty acids, including trans-palmitoleic acid were measured in 1992 using stored blood samples, and the participants were monitored for the development of Type 2 diabetes.
At the beginning of the study, the researchers noted that higher levels of trans-palmitoleic acid were associated with healthier cholesterol levels, insulin levels, inflammatory markers, and insulin sensitivity, even after adjustment for other risk factors. During the follow-up period, participants with higher levels of trans-palmitoleic acid were found to have a much lower risk of developing Type 2 diabetes, with those in the top quintile (the top 20%) of trans-palmitoleic acid having a 60% lower risk of developing the condition.
According to lead study author Dariush Mozaffarian, MD, “this type of observational finding requires confirmation in additional observational studies and controlled trials, but the magnitude of this association is striking. This represents an almost three-fold difference in risk of developing diabetes among individuals with the highest blood levels of this fatty acid.”
The next step forward, the researchers suggest, is to stage an intervention trial (a type of trial in which participants are given the treatment that is being evaluated) to see the effects on Type 2 diabetes risk. In the meantime, nutritionists on the American Diabetes Association nutrition task force maintain that the recommendation limiting dairy fat is still good. “This is an observational study that suggests a direction research should go in,” says Marion Franz, MS, RD, “but we have seen these studies before suggesting that a single micronutrient or food is protective and little has come of it.”
To learn more about the research, read the article “Component in Common Dairy Foods May Cut Diabetes Risk, Study Suggests” or see the study’s abstract in the Annals of Internal Medicine.