Decreasing the linoleic acid to alpha-linolenic acid diet ratio increases eicosapentaenoic acid in erythrocytes in adults

Lipids. 2010 Aug;45(8):683-92. doi: 10.1007/s11745-010-3430-3. Epub 2010 May 22.


The n-6/n-3 fatty acid (FA) ratio has increased in the Western-style diet to approximately 10-15:1 during the last century, which may have contributed to the rise in cardiovascular disease (CVD). Prior studies have evaluated the effects on CVD risk factors of manipulating the levels of n-6 and n-3 FA using food and supplements or investigated the metabolic fate of linoleic acid (LNA) and alpha-linolenic acid (ALA) by varying the n-6/n-3 ratios. However, no previous studies have investigated the potential interaction between diet ratios and supplementation with eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3). We used a factorial design approach with adults (n = 24) in a controlled feeding trial to compare the accretion of EPA and DHA into red blood cell membranes (RBC) by adding a direct source (algal oil supplement) of EPA and DHA in a diet with a 10:1 versus 2:1 ratio of n-6/n-3 FA. Subjects were randomized into 8-week crossover diet sequences and each subject consumed three of four diets [10:1, 10:1 plus supplement (10:1 + S), 2:1 and 2:1 + S]. LNA and ALA intakes were 9.4 and 7.7%, and 1.0 and 3.0% during the low and high ALA diets, respectively. Compared to the Western-style 10:1 diet, the 2:1 diet increased EPA by 60% (P < 0.0001) in RBC membranes without the direct EPA source and a 34% increase (P = 0.027) was observed with the 10:1 + S diet; however, DHA levels increased in both diet ratios only with a direct DHA source. Shifting towards a 2:1 diet is a valid alternative to taking EPA-containing supplements.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Eicosapentaenoic Acid / metabolism*
  • Erythrocytes / drug effects
  • Erythrocytes / metabolism*
  • Female
  • Humans
  • Linoleic Acid / administration & dosage
  • Linoleic Acid / pharmacology*
  • Lipid Metabolism / drug effects
  • Male
  • Middle Aged
  • alpha-Linolenic Acid / administration & dosage
  • alpha-Linolenic Acid / pharmacology*


  • alpha-Linolenic Acid
  • Linoleic Acid
  • Eicosapentaenoic Acid