BOSTON — Another article has focused on the health effects of saturated fat. This one, in contrast to two other articles, delivers a more negative message on saturated fat.
Unsaturated fats, especially polyunsaturated fats, and/or high quality carbohydrates may be used to replace saturated fats to reduce coronary heart disease, according to a study that appeared on-line Sept. 28 in the Journal of the American College of Cardiology.
The study comes after a financial services company, Credit Suisse, on Sept. 17 issued a report predicting saturated fat intake will increase through 2030 as negative perceptions gradually disappear. Journalist Nina Teicholz, in an article that appeared on-line Sept. 24 in the BMJ, criticized the Dietary Guidelines Advisory Committee 2015 over its recommendations to limit saturated fat intake.
The study in the Journal of the American College of Cardiology involved researchers from the Harvard T.H. Chan School of Public Health in Boston, the Harvard Medical School in Boston and the Wellness Institute at the Cleveland Clinic in Lyndhurst, Ohio. They looked at 84,628 women in the Nurses’ Health Study from 1980 to 2010 and 42,908 men in the Health Professionals Follow-up Study from 1986 to 2010.
People were free of diabetes, cardiovascular disease and cancer at baseline. Food frequency questionnaires assessed diet every four years. The researchers documented 7,667 cases of coronary heart disease during follow-up.
The study found replacing 5% of energy intake from saturated fats with equivalent intake from polyunsaturated fatty acids (PUFAs) was associated with a 25% lower risk of coronary heart disease. Replacing 5% of saturated fat energy intake with monounsaturated fatty acids was associated with a 15% lower risk, and replacing 5% of saturated fat energy intake with carbohydrates from whole grains was associated with a 9% lower risk. Replacing saturated fats with carbohydrates from refined starches/added sugars was not significantly associated with coronary heart diseases risk.
“Our findings suggest that the low-fat, high-carb trends of the 1980s and 1990s are not effective in reducing risk of C.H.D.,” said Yanping Li, Ph.D., one of the study’s authors and a researcher in the Department of Nutrition at the Harvard T.H. Chan School of Public Health. “It means that individuals should not replace saturated fat with refined carbs or vice versa. Dietary recommendations to reduce saturated fats should specify their replacement with unsaturated fats or with healthy carbohydrates such as whole grains.”
Grants from the National Institutes of Health supported the study.
For its report “Fat: The New Health Paradigm,” Credit Suisse evaluated 400 medical research papers and books. Credit Suisse forecast global saturated fat intake to grow to 12.7% of daily energy intake in 2030 from 9.4% in 2011.
“Based on medical and our own research, we can conclude that the intake of saturated fat (butter, palm and coconut oil and lard) poses no risk to our health and particularly to the heart,” the Credit Suisse report said.
Ms. Teicholz wrote the book “The Big Fat Surprise; Why Butter, Meat, & Cheese Belong in a Healthy Diet.” In her article in the BMJ she criticized the Dietary Guidelines Advisory Committee for its recommendation to limit saturated fat intake to 10% of calories. She said the D.G.A.C. did not ask the Nutrition Evidence Library to conduct a formal review of the literature from the past five years. For example, a Women’s Health Initiative clinical trial involved nearly 49,000 people and found no benefits for people who had a significantly lower intake of saturated fat in incidence of coronary heart disease and total cardiovascular disease.
“The omissions seem to suggest a reluctance by the committee behind the report to consider any evidence that contradicts the last 35 years of nutritional advice,” Ms. Teicholz said in the article.
The BMJ allowed Barbara Millen, committee chair for the D.G.A.C, to respond in the article.
“You don’t simply answer these questions on the basis of the N.E.L.,” she said. “Where we didn’t feel we needed to, we didn’t do them. On topics where there were existing comprehensive guidelines, we didn’t do them. We used those resources and that time to cover other questions. The notion that every question that we posed should have a N.E.L. is flawed.”Other groups beside the D.G.A.C. view saturated fats negatively. The American Heart Association advises healthy Americans over age 2 to limit their saturated fat intake to less than 7% of total daily calories. PepsiCo, Inc., Purchase, N.Y., has a goal of reducing the average amount of saturated fats per serving in key global food brands in key countries by 15% by 2020 compared to a 2006 baseline, according to a sustainably report the company released in September of this year.