Omega-3 fatty acids excel at quelling inflammation. More than two decades of research and several hundred papers on the cellular effects of omega-3 fatty acids have shown how they suppress the production of two classes of chemical messengers of inflammation. These are eicosanoids (prostaglandins) and cytokines, which are produced by the white blood cells in response to pro-inflammatory stimuli.
At the sites of tissue injury, immune cells create inflammation in an effort to heal the injury. When immune cells become activated to produce inflammation and inflammatory messenger molecules (the eicosanoids), the principle fatty acid in the cell envelope – arachidonic acid – catalyzes this transformation and can be metabolized into activated eicosanoids such as prostaglandins and leukotrienes.
However, omega-3 fatty acids lower the arachidonic acid content of the cell envelope by displacing it. Then if the cell is exposed to tissue injury, signals via the omega-3s do not lead to transformation of the cell into an “armed” inflammatory cell – rather it remains “neutral”. The end result is a dampening-down of the inflammatory process, with less pain, swelling, and other signs of inflammation, but without impairment of normal tissue repair.(1,2) It has also been demonstrated that omega-3 fatty acids reduce the enzymes responsible for joint destruction.(3)
Besides “crowding out” excess arachidonic acid, omega-3s aid the body in other ways. Both EPA and DHA have been shown to suppress the inflammatory cytokines TNF-a, IL-6, IL-1b, and IL-8. In addition, these omega-3s help to suppress the formation of prostaglandin E2 – a culprit in inflammation – and promote synthesis of the beneficial prostaglandin E3, further reducing inflammation.(1,4,5) They have also been shown to act on intracellular signaling pathways, to influence transcription factor activity, and to modulate gene expression.
All of these effects combine to help alleviate inflammation and disease. As one researcher noted,
“Many of the placebo-controlled trials of fish oil in chronic inflammatory diseases reveal significant benefit, including decreased disease activity and lowered use of anti-inflammatory drugs.” (6)
Omega-3 supplementation can be used concomitantly with anti-inflammatory pharmaceuticals, which may increase efficacy and reduce the risk of gastrointestinal discomfort, which is a regular problem for NSAID drugs. (7)
A high dietary intake of omega-3 fatty acids is effective in reducing the inflammatory response through inhibiting arachidonic acid metabolism and promoting the production of fewer inflammatory mediators.
- Endres S. et al. "The effect of dietary supplementation with n-3 polyunsaturated fatty acids on the synthesis of interleukin-1 and tumour necrosis factor by mononuclear cells". N Engl J Med 1989; 320:265-71.
- Denzlinger C. et al. "Modulation of the endogenous leukotriene production by fish oil and vitamin E". J Lipid Mediat Cell Signal 1995; 11:119-32.
- Curtis CL, Hughes CE, Flannery CR, et al. "n-3 fatty acids specifically modulate catabolic factors involved in articular cartilage degradation". J Biol Chem 2000;275:721-724
- James M. et al. "Dietary polyunsaturated fatty acids and inflammatory mediator production". Am J Clin Nutr 2000; 71:343S-8S.
- Caughey G.E. et al. "The effect on human tumor necrosis factor alpha and interleukin 1 beta production of diets enriched in n-3 fatty acids from vegetable oil or fish oil". Am J Clin Nutr 1996 Jan; 63(1):116.22.
- Simopoulos AP. "Omega-3 fatty acids in inflammation and autoimmune diseases". Am J Clin Nutr 2002 Dec;21(6):495-505.
- Lau CS et al. "Effects of fish oil supplementation on non-steroidal anti-inflammatory drug requirement in patients with mild rheumatoid arthritis - a double-blind placebo controlled study". Br J Rheumatol 1993;32:982-989