Dietary linoleic acid has no effect on arachidonic acid, but increases n-6 eicosadienoic acid, and lowers dihomo-gamma-linolenic and eicosapentaenoic acid in plasma of adult men

Prostaglandins Leukot Essent Fatty Acids. 2009 Apr;80(4):201-6. doi: 10.1016/j.plefa.2009.02.003. Epub 2009 Apr 8.


High intakes of linoleic acid (LA,18:2n-6) have raised concern due to possible increase in arachidonic acid (ARA, 20:4n-6) synthesis, and inhibition of alpha linolenic acid (ALA, 18:3n-3) desaturation to eicosapentaenoic (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3). In healthy men, 10.5% energy compared to 3.8% energy LA with 1% energy ALA increased plasma phospholipid LA and 20:2n-6, the elongation product of LA, and decreased EPA, with no change in ARA. However, LA was inversely related to ARA at both 10.5% energy and 3.8% energy LA, (r=-0.761, r=-0.817, p<0.001, respectively). A two-fold variability in ARA among individuals was not explained by the dietary LA, ARA, ALA, or fish intake. Our results confirm LA requirements for ARA synthesis is low, <3.8% energy, and they suggest current LA intakes saturate Delta-6 desaturation and adversely affect n-3 fatty acid metabolism. Factors other than n-6 fatty acid intake are important modifiers of plasma ARA.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 8,11,14-Eicosatrienoic Acid / blood*
  • Adult
  • Arachidonic Acid / blood*
  • Cross-Over Studies
  • Diet*
  • Eicosanoic Acids / blood*
  • Humans
  • Linoleic Acid / administration & dosage*
  • Male
  • Middle Aged
  • Randomized Controlled Trials as Topic


  • Eicosanoic Acids
  • eicosa-11,14-dienoic acid
  • Arachidonic Acid
  • Linoleic Acid
  • 8,11,14-Eicosatrienoic Acid