HIGH MONOUNSATURATED FAT DIET BEATS LOWFAT DIET IN GUARDING AGAINST HEART DISEASE
MODIFYING BALANCE OF FATTY ACIDS, RATHER THAN LOWERING FAT INTAKE, MAY PRODUCE BETTER CLINICAL RESULTS
Low-fat, no-fat. It's become such a health creed in the mind of the general public that grocery store shelves are now brimming with food products whose packaging proudly trumpets claims like "99% FAT-FREE!" But as results of recent clinical studies pour in, the new consensus is that eliminating or reducing all types of fat indiscriminately may not be the most effective approach for guarding against the development of cardiovascular disease (CVD) and other health problems.
Clinical nutritionists from The Pennsylvania State University and University of Rochester Medical Center report that increasing the percentage of monounsaturated fatty acids, or MUFAs (found in peanut oil and olive oil), in the diet, without changing total fat intake, may be more effective than adopting the low-fat, high-carbohydrate Step II diet. The Step II diet is currently advocated by the National Cholesterol Education Program/American Heart Association (AHA) to improve a patient's cardiovascular profile.
In the study, both dietary approaches triggered an approximately 14% drop in LDL cholesterol levels. The lowfat Step II diet, however, actually raised levels of potentially harmful markers such as triglycerol and lipoprotein (a) and lowered levels of beneficial HDL cholesterol, thereby mitigating some of its positive effects. The high MUFA diet, which still maintains the same total fat intake of the average American diet (34%), also reduced triglycerol levels by 13%, without significantly lowering good HDL cholesterol or raising lipoprotein (a).
In a related editorial, Dr. Elaine B. Feldman observes that while the Step II lowfat diet decreases cardiovascular risk by about 12%, the high MUFA diets reduce cardiovascular risk by as much as 18% - without reducing total fat intake. In addition to their clear benefits in regard to lipid markers, "MUFAs may also reduce CVD risk with their antioxidant, antithrombotic, and antihypertensive properties," she notes.
In response to this mounting clinical evidence, a recent AHA Science Advisory suggests that replacing saturated fats and carbohydrates in the diet with MUFAs may be a more effective option for improving cardiovascular function, lipid profiles, and glycemic control in patients who do not need to lose weight. MUFAs have been linked to lower risk of ischemic stroke, decreased oxidative damage, and improved insulin sensitivity, among other benefits. Foods high in MUFAs include nuts, avocados, olives, sesame seeds, and tahini. Individualizing dietary strategies to match each patient's unique clinical needs and food preferences promises greater patient compliance and health benefits, the advisory emphasizes.
NOTE: To develop the most effective, individualized nutritional dietary approach, each patient's fatty acid status should be evaluated using the Essential and Metabolic Fatty Acids Analysis (http://www.gsdl.com/services/emfa.html). This comprehensive profile measures 30+ markers and five ratios, and determines each patient's nutritional need for specific monounsaturates (omega-9) and polyunsaturates (omega-3 and omega-6), while alerting the clinician to high levels of damaging saturated fats and trans-fatty acids.
To accurately monitor the effect of dietary intervention on all important cardiovascular markers - not just cholesterol - the Comprehensive Cardiovascular Assessment (http://www.gsdl.com/services/cardiovascular.html) includes a complete array of independent analytes, including lipoprotein (a), homocysteine, C-reactive protein, and fibrinogen, as well as triglycerides, LDL, HDL, apo A-1, apo-B, total cholesterol, and ratios.
Sources:
Kris-Etherton PM, Pearson TA, Wan Y, Hargrove RL, Moriarty K, Fishell V. High-monounsaturated fatty acid diets lower both plasma cholesterol and triacylglycerol concentrations. Am J Clin Nutr 1999;70:1009-15.
Feldman B. Assorted monounsaturated fatty acids promote healthy hearts. Am J Clin Nutr 1999;70:953-4.
Kris-Etherton PM. Monounsaturated fatty acids and risk of cardiovascular disease. Circulation 1999;100:1253-1258.
