Dietary n-6 and n-3 fatty acid balance and cardiovascular health

• Published in: Annual review of nutrition 2004-01, Vol.24 (1), p.597-615
• Main Authors: Wijendran, V, Hayes, K.C
• Format: Article
• Language: English
• Subjects: alpha-Linolenic Acid; Animals; Biological and medical sciences; Blood pressure; Cardiovascular diseases; Cardiovascular Diseases - prevention & control; Diet; Dietary Fats, Unsaturated - administration & dosage; Dietary Fats, Unsaturated - metabolism; docosahexaenoic acid; Docosahexaenoic Acids; Eicosapentaenoic Acid; essential fatty acids; Fatty acids; Fatty Acids, Omega-3 - administration & dosage; Fatty Acids, Omega-3 - metabolism; Fatty Acids, Omega-6 - administration & dosage; Fatty Acids, Omega-6 - metabolism; Feeding. Feeding behavior; food intake; Fundamental and applied biological sciences. Psychology; human nutrition; Humans; linoleic acid; Linoleic Acids; linolenic acid; Linolenic Acids; literature reviews; Nutritional Requirements; omega-3 fatty acids; omega-6 fatty acids; Risk Factors; Vertebrates: anatomy and physiology, studies on body, several organs or systems
• ISSN: 0199-9885; 1545-4312
• DOI: 10.1146/annurev.nutr.24.012003.132106

Epidemiological and clinical studies have established that the n-6 fatty acid, linoleic acid (LA), and the n-3 fatty acids, linolenic acid (LNA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) collectively protect against coronary heart disease (CHD). LA is the major dietary fatty acid regulating low-density lipoprotein (LDL)-C metabolism by downregulating LDL-C production and enhancing its clearance. Further, the available mass of LA is a critical factor determining the hyperlipemic effects of other dietary fat components, such as saturated and trans fatty acids, as well as cholesterol. By contrast, n-3 fatty acids, especially EPA and DHA, are potent antiarryhthmic agents. EPA and DHA also improve vascular endothelial function and help lower blood pressure, platelet sensitivity, and the serum triglyceride level. The distinct functions of these two families make the balance between dietary n-6 and n-3 fatty acids an important consideration influencing cardiovascular health. Based on published literature describing practical dietary intakes, we suggest that consumption of ~6% en LA, 0.75% en LNA, and 0.25% en EPA + DHA represents adequate and achievable intakes for most healthy adults. This corresponds to an n-6/n-3 ratio of ~6:1. However, the absolute mass of essential fatty acids consumed, rather than their n-6/n-3 ratio, should be the first consideration when contemplating lifelong dietary habits affecting cardiovascular benefit from their intake.