For those trying to eat a healthy diet, whole-fat dairy and trans fats are usually not on the menu – at least, not yet. Scientists have narrowed in on a trans fat component found mainly in dairy fat that may ward off type 2 diabetes and protect cardiovascular health. While the research is far from conclusive and requires much further study, it suggests fats may play a more complex role in human health than previously thought.
Researchers found that adults with high levels of a fatty acid (one of the main parts of fat molecules) called trans-palmitoleic acid in their blood had a three-fold lower risk for diabetes, according to a study published Monday in the Annals of Internal Medicine. This naturally produced trans fat component is found mainly in dairy, as well as some meats. These subjects also had lower body fat, higher good cholesterol levels, and lower triglyceride levels, which are all associated with better cardiovascular well-being.
“It’s exciting because traditionally fats were just seen as artery cloggers, but they seem to be both harmful and protective,” said lead author and Harvard epidemiologist Dariush Mozaffarian. “The fatty acid world is becoming more interesting and complex.”
Little is known about trans-palmitoleic acid. In a 1970 study, nutritionists found it comprised only 0.2 percent of all dairy fats. Mammals actually don’t produce it naturally. Bacteria found in cattle make the fatty acid during digestion, and it eventually finds its way to their milk.
Mozaffarian and his colleagues grew interested in the fatty acid after examining a small body of evidence linking dairy consumption with lower diabetes and cardiovascular disease risk factors. “Because trans-palmitoleic acid is fairly unique to dairy, we knew if we found it in subjects there’s a good chance it came from eating some dairy product,” he said.
Analyzing blood samples and lifestyles of more than 3,700 adults 65 years or older, Mozzaffarian found that even when adjusting for various demographic and lifestyle differences, subjects with high levels of trans-palmitoleic acid or reported eating whole-fat dairy appeared to be in better shape than those who didn’t. 739 people in the study had trans-palmitoleic acid at the highest protective level. The acid was found in each person studied.
“This one of the strongest confirmations that there’s something in dairy fat that lowers risk of diabetes,” Mozzaffarian said.
That doesn’t mean you should put down the skim milk and reach for the half and half, however. Excess calories can lead to weight gain which, going unchecked, is a contributing factor in diabetes, heart disease and a number of other health problems. This is only one study that does not show trans-palmitoleic acid or whole-fat dairy directly caused these differences. However, it’s widely accepted that diets high in the saturated fats found in dairy products often lead to diabetes and cardiovascular disease.
“We certainly know that eating a lot of saturated fat is associated with some bad consequences,” said American Diabetes Association Senior Vice President of Medical Affairs and Community Information Dr. Sue Kirkman. “This study is interesting, but people shouldn’t conclude they should eat or drink high fat dairy products. It does, however, generate a great hypothesis for future study.”
Mozaffarian agrees. He hopes others will look further at trans-palmitoleic acid and it’s effects in the body. If trans-palmitoleic acid is found to guard against diabetes or cardiovascular disease, he envisions that maybe manufacturers can increase its concentration in dairy products or use it as a supplement.
“It’s exciting because it might be able to reduce the epidemic of diabetes across the whole world,” Mozaffarian said. “But this is really new science, so we don’t want to oversell this. It could be a flash in a pan that turns out to not be correct.”