Strong evidence shows replacing saturated fat with unsaturated fats, especially polyunsaturated fats, reduces L.D.L. “bad” cholesterol and cardiovascular disease risk, the Dietary Guidelines Advisory Committee said Dec. 15 in its seventh and final meeting. The D.G.A.C. also said strong evidence shows replacing saturated fat with overall carbohydrates does not lower cardiovascular risk.
The committee recommends retaining the 10% upper limit for saturated fat intake, a view that drew a positive response from Gerald McNeill, Ph.D., vice-president of research and development for Loders Croklaan, a palm oil company that has a U.S. office in Channahon, Ill.
“The transcript of the final D.G.A.C. meeting, just released, revealed that while the D.G.A.C. remains concerned with high intakes of saturates, the recent flood of positive news around saturated fat is having an impact,” he said. “Their final recommendation will likely be to restrict saturated fat intake to a maximum of energy 10% of the diet, preferably to be substituted with polyunsaturated fat.
“A maximum level of about energy 10% for saturated fat has consistently been recommended by D.G.A.C.s with a couple of recent exceptions. Major changes in traditional saturated fat consumption are likely to have negative unforeseen consequences, such as an increase in heart disease from trans fat and substitution of fat with sugar, now attributed to the obesity and type 2 diabetes epidemics in the U.S. A moderate approach to saturated fat will deliver the best outcomes.”
Since the 2010 guidelines came out, and even before then, the palm oil industry has sought to improve the health image of saturated fats. Some scientific studies have benefited that cause. Palm oil contains about 50% saturated fat.
Dr. McNeill and other saturated fat proponents argue saturated fats increase both H.D.L., or “good” cholesterol, and L.D.L., or “bad” cholesterol. They say people formulating dietary advice should give more emphasis to the ratio of total cholesterol to L.D.L. Dr. McNeill said the current Dietary Guidelines Advisory Committee has given little emphasis to H.D.L. benefits, which he found disappointing but to be expected.
“Looking through the transcripts, they mention H.D.L. as well, but what they are really focusing on is L.D.L.,” Dr. McNeill said.
Last March the Annals of Internal Medicine published a meta-analysis from the University of Cambridge that showed current evidence does not support guidelines that restrict the consumption of saturated fat to prevent heart disease. The researchers analyzed data from 27 studies with more than 600,000 people from 18 nations.
Several health experts, notably Walter Willett, Ph.D., chair of the Nutrition Department at the Harvard School of Public Health in Boston, criticized the study and said it had errors. The Dietary Guidelines Advisory Committee also apparently will keep associating saturated fat with cardiovascular disease.
The Healthy Nation Coalition in a letter also spoke up for saturated fats and pointed to not only the Annals of Internal Medicine study but also a study that appeared in the March 1, 2010, issue of The American Journal of Clinical Nutrition.
The Healthy Nation Coalition sent its letter criticizing various aspects of past guidelines to the U.S. Department of Agriculture and the U.S. Department of Health and Human Services. About 600 people, including clinicians, academics, farmers and ranchers, signed the letter.Next, the D.G.A.C. will issue a final report to the secretaries of the U.S.D.A. and the H.H.S. Throughout the winter, spring and summer of 2015, the U.S.D.A. and the H.H.S. will consider the D.G.A.C.’s recommendations along with public comments and agency comments. The H.H.S. and the U.S.D.A. jointly should publish the eighth edition of the dietary guidelines by the end of 2015.