How relevant is the ratio of dietary n-6 to n-3 polyunsaturated fatty acids to cardiovascular disease risk? Evidence from the OPTILIP studyGriffin, Bruce ACurrent Opinion in Lipidology: February 2008 - Volume 19 - Issue 1 - p 57–62 doi: 10.1097/MOL.0b013e3282f2e2a8 Nutrition and metabolism: Edited by Paul Nestel and Ronald Mensink Abstract Author Information Purpose of review: There has been much debate over the practical utility of the dietary ratio of n-6 to n-3 polyunsaturated fatty acids in optimizing the benefits of n-3 fatty acids (C18–C22) on cardiovascular health. This review examines the supporting evidence from the OPTILIP study within the context of the emerging consensus on the value of this dietary metric. Recent findings: The question of whether the ratio of n-6/n-3 polyunsaturated fatty acids or total amounts of dietary polyunsaturated fatty acids is of more importance to cardiovascular health has been addressed recently in a randomly controlled trial (OPTILIP) and in a stable isotope tracer study. These two studies were independently unanimous in concluding that the ratio of n-6/n-3 polyunsaturated fatty acids is of no value in modifying cardiovascular disease risk. The latter study also showed that the absolute amounts of dietary linoleic acid and α-linolenic acid are of relevance to the efficiency of conversion of α-linolenic acid to eicosapentaenoic acid and docosahexaenoic acid. Summary: This review should help to settle any outstanding controversy over the dietary ratio of n-6/n-3 polyunsaturated fatty acids. It reinforces current recommendations to increase the consumption of preformed eicosapentaenoic acid/docosahexaenoic acid in fish, and supports dietary measures to increase and decrease intakes α-linolenic acid and linoleic acid, respectively, to promote the endogenous synthesis of these longer chain n-3 polyunsaturated fatty acids. Faculty of Health & Medical Sciences, University of Surrey, Guildford, Surrey, UK Correspondence to Dr Bruce A. Griffin, Faculty of Health & Medical Sciences, University of Surrey, Guildford, Surrey GU2 7XH, UK Tel: +44 (0)1483 879724; fax: +44 (0)1483 686401; e-mail: firstname.lastname@example.org © 2008 Lippincott Williams & Wilkins, Inc.