Thursday, February 24, 2011

High MUFA Diets are (Heart-)Healthy and Probably Superior to High PUFA Diets

Ever since the "Mediterranean Diet" was/is the talk of the town, more and more people become aware of the potential benefits of the formerly largely ignored mono-unsaturated fatty acids (MUFAs). In spite of that, the majority of consumers (probably due to the misinformation coming from the marketing machinery of the food industry) still focuses on avoiding the "bad" saturated fats and consuming as much "healthy" polyunsaturated fats (PUFAs) as possible in order not to fall victim to an obesity epidemic which is inseparably intertwined with these kind of black-and-white approaches to nutrition.

In an extensive review (Jones. 2011) scientists from the Department of Human Nutritional Sciences at the Richardson Centre for Functional Foods and Nutraceuticals (University of Manitoba, Canada) evaluated data from over 50 years of research to come to the conclusion:
Consumption of dietary MUFA promotes healthy blood lipid profiles, mediates blood pressure, improves insulin sensitivity and regulates glucose levels. Moreover, provocative newer data suggest a role for preferential oxidation and metabolism of dietary MUFA, influencing body composition and ameliorating the risk of obesity. Mounting epidemiological and human clinical trial data continue to demonstrate the cardioprotective activity of the MUFA content of dietary fat.
In fact, they found MUFA rich diets to be superior even to diets enriched in PUFAs, which have lately oftentimes been hailed as the saviors of the fat and unhealthy:
When PUFA and MUFA rich diets were compared for replacement of dietary SFA in healthy adult subjects, those consuming MUFA rich diets demonstrated a preservation of HDL-C levels to a greater extent with only a 4% decrease in HDL-C levels compared to those consuming PUFA rich diets, which decreased HDL-C levels by 14%.
What is interesting, however, is that there still seems to be an initial bias against saturated fatty acids. This can also be seen from the fact that the general questions the authors pose throughout their review always come back to the idea of replacing saturated fatty acids by either carbs or MUFA, PUFA or MUFA etc. I would be interested to see a study or a review without this initial bias against saturated fats - the results could be very interesting... what do you think?