Individual fattyacideffectson plasmalipidsand lipoproteins: human ,2

The purpose of this review is to summarizeour current understanding of the cholesterolemic effects of individual fatty acids. Although historically there has been great interest in the fatty acid classes, it has been only recently that emphasis has shifted to individual fatty acids. Consequently, and in conjunction with the methodologic challenges inherent in studying individual fatty acids, our database is relatively modest. Nonetheless, it is clear that saturated fatty acids are hypercholesterolemic and that unsaturated fatty acids elicit a hypocholesterolemic effect corn pared with saturated fatty acids. The question at hand is, What are the relative cholesterolemic effects of the major saturated and unsaturated fatty acids in the diet? On the basis of a limited number of well-controlled studies, it appears that myristic acid is the most potent saturated fatty acid. Of the saturated fatty acids, stearic acid is uniquely different in that it appears to be a neutral fatty acid. Monounsaturated fatty acids appear to exert a neutral effect or to be mildly hypocholesterolemic. trans Fatty acids elicit effects that are intermediate to those of the hypercholesterolemic saturated fatty acids and the cis-monounsaturated and cis-polyun saturated fatty acids. Polyunsaturated fatty acids elicit the most potent hypocholesterolemic effects. Studies are needed to establish the potency with which each fatty acid affects plasma total and lipoprotein cholesterol concentrations as well as the mechanisms that account for their markedly different effects. This information will be useful in making dietary recommendations for individual fatty acids that may further reduce risk of chronic diseases in the United States. Am J Clin Nutr 1997;65(suppl): 16285â€"445. were conducted to evaluate the cholesterolemic effects of the fatty acid classes and not specifically of individual fatty acids. Over the years, numerous feeding studies corroborated the blood cholesterol predictive equations and showed that satu rated fatty acids were hypercholesterolemic and that polyun saturated fatty acids lowered blood cholesterol concentrations. Both regression analyses and controlled feeding studies have shown that monounsaturated fatty acids have either a neutral or mildly hypocholesterolemic effect. The results of these studies were used to make specific dietary recommendations for the prevention and treatment of coronary artery disease. Only recently has interest emerged regarding understanding the cholesterolemic effect of individual fatty acids. As a result, some studies have been conducted to examine the specific effects of individual fatty acids on plasma total and lipoprotein cholesterol concentrations. Information from additional and more definitive studies could provide the basis for making dietary recommendations for individual fatty acids, which could be of public health significance. This review summarizes and critically evaluates the litera tare that forms the basis of our current understanding of the effects of specific fatty acids on plasma lipids and lipoproteins, especially low-density-lipoprotein (LDL)-cholesterol concen trations. Although the emphasis is on the well-controlled feed ing studies, other experimental approaches (eg, regression anal yses and feeding studies that have evaluated fatty acid classes) will also be discussed because they have been integral in developing our present understanding.