Fats are composed of fatty acids and glycerol strung together in a chain. Each of those fatty acids are classified as one of three types: saturated fatty acids (SFAs), polyunsaturated fatty acids (PUFAs) or monounsaturated fats (MUFAs). Organizations like the World Health Organization and the U.S. Department of Agriculture recommend a diet lower in SFAs and carbohydrates and higher in MUFAs and protein for a number of health reasons, among them reduced cardiovascular risk and improved blood sugar maintenance. Food sources of MUFAs include olive oil, canola oil and other vegetable oils containing oleic acid, as well as nuts, poultry and meats.
Fats
The proportion of SFAs, PUFAs and MUFAs in any given fat determines its health effects. In general, all fats provide the body 9 calories per gram and assist in the absorption of the fat-soluble vitamins, including A, D, E and K.
Weight Control
One of the most popularly cited health benefits of MUFAs in the media is its purported weight loss effects, and more particularly its alleged ability to help get rid of belly fat. While the scientific research on this possible dietary effect of MUFAs is less abundant than that on its benefits for blood sugar maintenance and reducing cardiovascular disease risk, a 2003 study in "Obesity Research" did confirm that a high-MUFA diet led to significant reductions both in body weight and waist circumference.
Blood Sugar Maintenance
MUFAs help the body to regulate blood sugar levels and maintain the proper balance of insulin in the blood. In a 2007 study published in the "Journal of the American College of Nutrition" researchers in Spain compared the effects of three weight-control diets -- including one MUFA-rich diet -- on factors of blood sugar and fat metabolism in insulin-resistant subjects. The MUFA-rich diet was found to improve insulin responsiveness and lower blood sugar. It also raised the levels of HDL cholesterol, or "good cholesterol." This evidence suggests that increasing MUFA intake over high-carbohydrate intake could benefit people with type 2 diabetes.
Cardiovascular Health
The USDA cites strong evidence indicating that replacing saturated fatty acids (SFAs) in the diet with MUFAs leads to improved cholesterol levels and that replacing just 5 percent of SFAs with MUFAs reduces risk of cardiovascular disease (CVD). Such evidence includes a 2005 study published in the "Journal of the American Medical Association" that found that a diet of MUFAs yielded lower lipid levels and lower blood pressure than a diet of carbohydrates and thus a lower "estimated 10-year coronary heart disease risk." A 2007 study in the "American Journal Of Clinical Nutrition," reported that patients already at risk of coronary heart disease received a greater reduction in that risk by replacing SFAs with MUFAs rather than carbohydrates.
References
- Dietary Guidelines Advisory Committee; "Report of the DGAC on the Dietary Guidelines for Americans, 2010. Part D. Section 3. Fatty Acids and Cholesterol"; 2010
- "Obesity Research"; Variations In Body Composition And Plasma Lipids In Response To A High-Carbohydrate Diet; W.R. Archer, et al.; Aug 2003
- "Journal Of The American College Of Nutrition"; A MUFA-rich Diet Improves Postprandial Glucose, Lipid And GLP-1 Responses In Insulin-resistant Subjects; J.A. Paniagua, et al.; Oct 2007
- USDA; What Is The Effect Of Dietary Intake Of MUFA On Health And Intermediate Health Outcomes?; 2010
- "Journal Of The American Medical Association"; Effects Of Protein, Monounsaturated Fat, And Carbohydrate Intake On Blood Pressure And Serum Lipids: Results Of The OmniHeart Randomized Trial; L.J. Appel, et al.; Nov 2005
- "American Journal Of Clinical Nutrition"; Comparison Of Monounsaturated Fat With Carbohydrate Replacement For Saturated Fat In Subjects With A High Metabolic Risk Profile: Studies In The Fasting And Postprandial States; L. Berglund, et al.; Dec 2007
