The Omega 3 fatty acids EPA and DHA found in fish and fish oil are known to decrease inflammation, but these fatty acids do more than that.
A more accurate way of describing the effect of the Omega 3 fat in fish and fish oil, is to say they regulate the immune system (Jaudszus A, et al. 2013).
At high doses they inhibit inflammation. They however have the ability both to activate anti-inflammatory cytokines and also activate cytokines that is involved in stimulation of the inflammatory response.
The Omega 3 fatty acids found in fish and fish oil additionally effect of resolving inflammation, helping to avoid an ongoing inflammatory response when you don’t need it anymore.
It is worthwhile to swallow some few fish oil capsules of high quality every day.
Reference
Anke Jaudszus 1, Michael Gruen, Bernhard Watzl, Christina Ness, Alexander Roth, Alfred Lochner, Dagmar Barz, Holger Gabriel, Michael Rothe, Gerhard Jahreis, Evaluation of suppressive and pro-resolving effects of EPA and DHA in human primary monocytes and T-helper cells, J Lipid Res. 2013 Apr;54(4):923-35.