Omega-6 fatty acids and inflammation

Prostaglandins Leukot Essent Fatty Acids. 2018 May:132:41-48. doi: 10.1016/j.plefa.2018.03.004. Epub 2018 Mar 22.

Abstract

Inflammation is a normal process that is part of host defence and tissue healing. However, excessive or unresolved inflammation can lead to uncontrolled tissue damage, pathology and disease. In humans on a Western diet, the omega-6 polyunsaturated fatty acid arachidonic acid (ARA) makes a significant contribution to the fatty acids present in the membrane phospholipids of cells involved in inflammation. ARA is a precursor to a number of potent pro-inflammatory mediators including well described prostaglandins and leukotrienes, which has led to the development of anti-inflammatory pharmaceuticals that target the ARA pathway to successfully control inflammation. Hence, it is commonly believed that increasing dietary intake of the omega-6 fatty acids ARA or its precursor linoleic acid (LA) will increase inflammation. However, studies in healthy human adults have found that increased intake of ARA or LA does not increase the concentrations of many inflammatory markers. Epidemiological studies have even suggested that ARA and LA may be linked to reduced inflammation. Contrastingly, there is also evidence that a high omega-6 fatty acid diet inhibits the anti-inflammatory and inflammation-resolving effect of the omega-3 fatty acids. Thus, the interaction of omega-3 and omega-6 fatty acids and their lipid mediators in the context of inflammation is complex and still not properly understood.

Keywords: Arachidonic acid; Dihomo-gamma-linolenic acid; Eicosanoid; Gamma-linolenic acid; Inflammation; Linoleic acid.

Publication types

  • Review

MeSH terms

  • Animals
  • Arachidonic Acid / administration & dosage
  • Arachidonic Acid / metabolism
  • Cytokines / biosynthesis
  • Dietary Fats / administration & dosage
  • Dietary Fats / metabolism*
  • Fatty Acids, Omega-3 / administration & dosage
  • Fatty Acids, Omega-3 / metabolism*
  • Fatty Acids, Omega-6 / administration & dosage
  • Fatty Acids, Omega-6 / metabolism*
  • Humans
  • Inflammation / metabolism*
  • Inflammation / pathology
  • Leukocytes / cytology
  • Leukocytes / metabolism
  • Leukotrienes / metabolism*
  • Linoleic Acid / administration & dosage
  • Linoleic Acid / metabolism
  • Lipid Metabolism
  • Lipoxins / metabolism
  • Prostaglandins / metabolism*
  • gamma-Linolenic Acid / administration & dosage
  • gamma-Linolenic Acid / metabolism

Substances

  • Cytokines
  • Dietary Fats
  • Fatty Acids, Omega-3
  • Fatty Acids, Omega-6
  • Leukotrienes
  • Lipoxins
  • Prostaglandins
  • Arachidonic Acid
  • gamma-Linolenic Acid
  • Linoleic Acid