A new study published in the Annals of Internal Medicine questions the information the public has been told about a link between saturated fat intake and heart disease risk. The study, called “Association of Dietary, Circulating, and Supplement Fatty Acids with Coronary Risk” is a meta analysis and review of studies conducted over the years and published in peer review journals.
The authors of the study did find a link between trans fats intake and heart disease. Trans fat is a “fake” fat that is made by bubbling hydrogen through oil to produce a solid product. It has been used for years in commercial products.
But they did not find evidence of dangers from saturated fat, the types of fats found in dairy and meat products. They also looked at possible benefits to eating foods rich in long-chain omega-3 and omega-6 polyunsaturated fatty acids.
Researchers looked at 32 observational studies with 512,420 participants, 17 observational studies with 25,721 participants, and 27 randomized trials with 105,085 participants. The authors say, “our findings do not support cardiovascular guidelines that promote high consumption of long-chain omega-3 and omega-6 and polyunsaturated fatty acids and suggest reduced consumption of total saturated fatty acids.” In other words, there is no evidence to justify the cardiovascular guidelines that have been drilled into the public consciousness that saturated fats are to be avoided.
Some of the details are interesting. There were weak positive associations between circulating palmitic and stearic acids, which are saturated, and cardiovascular disease, but circulating margaric acid, which comes from dairy products, significantly reduced the risk of heart disease. There was no benefit from circulating levels of omega-3 and omega-6 fatty acids, the polyunsaturated fats that are supposedly good for the heart.
But, like all individual studies, even meta-analyses of multiple studies, this information should be taken with a grain of salt. The recommendations of nutritionists are based on overall trends and years of study. Large scale clinical studies are needed, according to the study’s authors, before anyone can make a conclusive judgement on the subject. A diet rich in whole foods, not smoking, and staying active remain the best good keys to good health.
