“For years everyone has been advised to cut out fats,” said lead author Russell de Souza, an assistant professor in McMaster’s Department of Clinical Epidemiology and Biostatistics. “Trans fats have no health benefits and pose a significant risk for heart disease, but the case for saturated fat is less clear.” He also noted that the researchers are not recommending an increase in saturated fat intake, because evidence does not show that it would benefit health.
Currently, people are recommended to limit saturated fats to less than 10 percent and trans fats to less than one percent of energy. Saturated fats are found in animal products like butter, cows’ milk, meat and egg yolks. Trans fats are mostly produced industrially from plant oils to make margarine, snack foods and packaged baked goods.
De Souza and his colleagues analyzed 50 observation studies examining the association between saturated and/or trans fats and health outcomes in adults. The researchers did not find an association between higher saturated fat consumption and death, coronary heart disease, cardiovascular disease, ischemic stroke or type 2 diabetes. Instead, they found that industrial trans fat consumption was associated with a 34 percent increase in death, a 28 percent increase in risk for CHD mortality and a 21 percent increase in risk for CHD.
“Ours and other studies suggest replacing foods high in these fats, such as high-fat or processed meats and donuts, with vegetables oils, nuts and whole grains,” de Souza said.