Recommendations to replace saturated fat with carbohydrates or polyunsaturated fat are “severely challenged” and should be revised, claims an editorial published in Open Heart, a new journal from the BMJ Group.
James DiNicolantonio, a cardiovascular research scientist and doctor of pharmacy at Ithaca, New York, builds on a previous commentary published in the British Medical Journal in October , in which cardiologist Aseem Malhotra claimed saturated fat in meat and dairy had been unfairly demonised. In particular, the two cardiovascular experts both claim that saturated fat is not as bad for heart health as the public has been led to believe.
“The benefits of a low-fat diet (particularly a diet replacing saturated fats with carbohydrates or omega-6 polyunsaturated fatty acids) are severely challenged,” wrote DiNicolantonio. “Dietary guidelines should assess the totality of the evidence and strongly reconsider their recommendations for replacing saturated fats with carbohydrates or omega-6 polyunsaturated fats.”
DiNicolantonio claims that increased intake of refined carbohydrates, including sugar, is actually to blame for a rapid increase in type-2 diabetes and obesity. He says dietary guidelines to reduce saturated fat intake were based on a flawed premise that saturated fat increased total cholesterol, and ignored evidence that replacing saturated fat with carbohydrate could worsen overall blood lipid profiles.
In addition, he says advice to replace saturated fats with polyunsaturated fats, without specifying omega-3s, may also have had harmful effects on heart health.
“Dietary guideline recommendations suggesting the replacement of saturated fat with carbohydrates/omega-6 polyunsaturated fats do not reflect the current evidence in the literature,” he wrote. “A change in these recommendations is drastically needed as public health could be at risk.”
Processed foods ‘should be avoided’
As for implications for the food industry, DiNicolantonio writes: “It would be naive to assume that any recommendations related to carbohydrate or fat intake would apply to processed foods, which undoubtedly should be avoided if possible.”
Commenting on the article, Professor of Nutrition at Robert Gordon University, Aberdeen, Brian Ratcliffe, said it was a welcome addition to the debate about dietary fat. However, he said DiNicolantonio’s assertion that refined carbohydrates and increased consumption of sugars in the USA were to blame was ‘simplistic’.
“The latter has occurred across much of the developed world without such obvious associations with dietary carbohydrate,” Ratcliffe said. “The most recent Cochrane review concluded that addressing the quality of fat in the diet could reduce cardiovascular events by 14% and perhaps that is worthy of consideration.”
Professor of Nutritional Metabolism at the University of Surrey, Bruce Griffin, added: “A more balanced review of the overall evidence would reveal that the risks from saturated fat and refined sugars are not mutually exclusive, but co-exist together in our diet. …Nutritional science is complex and imperfect, making it feasible to construct logical and compelling arguments that either one of these dietary components can exert more or less cardiovascular risk.”
The commentary comes on the heels of a Swedish study that suggested saturated fats were indeed linked to disease risk , influencing heart disease risk, cholesterol levels and where fat is stored in the body.
DiNicolantonio’s commentary is available online here .