By Steve Stiles
"The influence of dietary fats on serum cholesterol has been overstated," concludes a review in an American Society for Nutrition publication that, in its words, "calls for a rational reevaluation of existing dietary recommendations that focus on minimizing dietary SFAs [saturated fatty acids], for which mechanisms for adverse health effects are lacking" .
Indeed, argues the author, Dr Glen D Lawrence (Long Island University, Brooklyn, NY), it is likely other factors, such as oxidized polyunsaturated fatty acids (PUFAs) or preservatives in processed meats, that are also present in high-SFA foods that lead to adverse health effects typically associated with high SFA intake.
"The meager effect that saturated fats have on serum cholesterol levels when modest but adequate amounts of polyunsaturated oils are included in the diet, and the lack of any clear evidence that saturated fats are promoting any of the conditions that can be attributed to PUFA, makes one wonder how saturated fats got such a bad reputation in the health literature," Lawrence writes in the review published May 1, 2013 in the journal Advances in Nutrition.
The article's case is built on interpretations of research from the biochemistry, epidemiologic, and clinical literature but which, nonetheless, does not reference a tremendous body of research supporting alternative views. Still, Lawrence describes:
- The role of lipid peroxidation in promoting atherogenesis, arguing that its effects are more pronounced on PUFA than on SFAs or monosaturated fatty acids.
- An arguably protective effect of omega-3 PUFAs against proinflammatory effects of omega-6 and other PUFAs.
- Evidence that potentially carcinogenic preservatives in processed meats as well as high-heat cooking methods have influenced perceptions that red meat per se has adverse health effects.
- How "the preparation and cooking methods used for foods that are traditionally classified as saturated fat foods may be producing substances from PUFAs and carbohydrates in those foods that are promoting disease."
- Studies suggesting positive health effects from dairy fat and tropical oils, both high in SFAs and therefore discredited as unhealthy.
- The hazards of diets with increased carbohydrates as a result of being lower in fat, in low-fat diets followed to improve health, especially cardiovascular health.
Lawrence had no disclosures.