Natural fatty acid in dairy products could curb diabetes risk
Consuming dairy products that contain a natural fatty acid called trans-palmitoleic acid could curb the chances of developing diabetes, found in an observational study.
Higher circulating levels of the dairy component that can’t be manufactured by the body was linked to healthier cholesterol levels, insulin response and lower inflammatory markers in study participants who were followed for 20 years.
Researchers from Harvard School of Public Health and Brigham and Women's Hospital and Harvard Medical School explain the findings might support recent epidemiological evidence that eating dairy products like milk, yogurt and cheese can lower the chances of diabetes, even though full fat dairy products are linked to higher risk of cardiovascular disease.
Dariush Mozaffarian, associate professor in the Department of Epidemiology at HSPH and Division of Cardiovascular Medicine who led the study says, "There has been no clear biologic explanation for the lower risk of diabetes seen with higher dairy consumption in prior studies.
This is the first time that the relationship of trans-palmitoleic acid with diabetes risk has been evaluated. We wonder whether this naturally occurring trans fatty acid in dairy fats may partly mimic the normal biologic role of its cis counterpart, cis-palmitoleic acid, a fatty acid that is produced in the body. In animal experiments, cis-palmitoleic acid protects against diabetes."
The researchers followed 3,736 participants in the National Heart, Lung, and Blood Institute-funded Cardiovascular Health for twenty years to find the health benefits of trans-palmitoleic acid in dairy products. In addition to measuring cholesterol, insulin sensitivity and inflammatory markers, the researchers checked circulating levels of the dairy product component , finding a 60 percent reduced risk of diabetes for participants with the highest levels.
Mozaffarian said, …"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."
He explains scientists have been unable to understand why dairy products are associated with lower diabetes risk, found in previous studies. He says it may be high calorie and carbohydrate diets might limit the synthesis of cis-palmitoleic acid that naturally occurs in the body. "We wonder whether trans-palmitoleic acid may be stepping in as a "pinch hitter" for at least some of the functions of cis-palmitoleic acid," said Mozaffarian - something that might explain the lower risk of diabetes found in the study.
The researchers plan to move forward with studies to see if therapies could be developed, based on the findings. The scientists say the “extremely strong” protection found from trans-palmitoleic acid in dairy products exceeds other known interventions for reducing diabetes risk factors.
Annals of Internal Medicine, December 20, 2010 vol. 153 no. 12 790-799