Does saturated fats clog your arteries? Controversial paper says 'no'

4/26/2017, 6 a.m.
It is common knowledge supported by health experts, the American Heart Association and the World Heart Federation: Eating saturated fats ...
Families with college-age kids can help students improve their financial health. (Photo: Statepoint)

— Plus, higher fat diets do not show saturated fats to be detrimental to coronary artery health.

For example, a Mediterranean diet supplemented with at least four tablespoons of extra virgin olive oil -- which contains 14% saturated fat -- or a handful of nuts each day achieved a significant 30% reduction in cardiovascular events in over 7,500 high-risk patients, noted Malhotra and his colleagues referencing the Primary Prevention of Cardiovascular Disease with a Mediterranean Diet study, known as the PREDIMED study. And, the Lyon Heart study showed that adopting a Mediterranean diet improved outcomes for both recurrent myocardial infarction and all-cause mortality, noted the authors.

Not everyone agrees with this interpretation of the two studies.

"The evidence cited to support that saturated fat does not increase the risk of CVD does not really support the claim: the PREDIMED study did not investigate differences in fat or saturated fat intake, the Lyon Heart study actually showed a beneficial effect," Dr. Gunter Kuhnle, an associate professor in nutrition and health at University of Reading, wrote in a published commentary.

Others believe evidence to support the claims of the authors is generally lacking.

Critics raise questions

Dr. David Nunan, senior researcher at the Centre for Evidence Based Medicine at the University of Oxford, wrote in a published comment that one of the studies cited as evidence in the editorial actually supports the "current consensus." Instead of disproving the benefits of reducing saturated fats, the cited study shows the beneficial effects of reducing saturated fats and replacing them with unsaturated fats for the general population.

According to Dr. Frank Sacks, former chair of the American Heart Association's nutrition committee, "the editorial is misleading, ignoring a large database of highest quality evidence that saturated fat does cause atherosclerosis, and does so in large part because it increases LDL-cholesterol." LDL cholesterol is "bad" cholesterol, responsible for plaque build-up in the arteries, while HDL cholesterol is "good," because it is able to clear away some of the build-up, according to the American Heart Association.

In an email, Sacks wrote that the authors used an "obsolete methodology" in their analysis. Studies that use a more sophisticated method of analysis consistently show lower cardiovascular disease rates when unsaturated fats replace saturated fats, he said.

The U.S. Department of Agriculture's food guide explicitly recommends you eat more unsaturated fat than both saturated and trans fats to reduce your risk of heart disease.

Unsaturated fats are the plant-based fats found in nuts, seeds, olives and also in fish. At room temperature, unsaturated fats are oils. Trans fats, which were once commonly found in snack foods, cakes, cookies, icings and margarines, are synthesized by adding hydrogen to vegetable oils. They were added to foods to prevent spoilage and to create better texture, yet the Food and Drug Administration ruled artificial trans fat as unsafe in 2015 and gave food manufacturers three years to remove them from their products.

Malhotra nevertheless maintains his position, noting "it's not the saturated fat that's the problem."