Omega-3s and other healthy oils are the building blocks for cell membranes. When a healthy cell becomes damaged, the torn cell membrane becomes the chemical signals to bring in the repair crew. The repair crews are the white blood cells and the inflammatory mediators that cause swelling and redness.
For an acute injury, the inflammatory mediators resolve the problems and facilitate the repairs. But for chronic inflammation, the inflammatory mediators just cause havoc since there is nothing to fix.
So that is how fish oils are closely linked to inflammation and the immune system. Their chemical structure is very similar to inflammatory signalers, aka eicosanoids.
Omega-3s, EPA and DHA, can compete with arachidonic acid (an inflammatory signaler) for activation enzymes. Therefore, higher concentrations of EPA and DHA than arachidonic acid tip the eicosanoid-define balance toward less inflammatory activity, polyunsaturated fatty acids (as arachidonic acid), and involved in cellular activity.
We know that fish oils improve systemic inflammation by looking at the inflammatory biomarkers such as CRP and IL-6. O3FA can significantly change the serum levels of CRP and IL-6 (ref 1). However, they are not always strong enough to change the disease state outcome or improve the quality of life. Sometimes, systemic inflammation is so out of control that monoclonal antibodies or glucocorticoid steroids are needed to change the course of the disease.
Medicinal oils that contain omega-3 fatty acids include, but are not limited to, fish oils. You can buy Omega 3 fatty acids in a pill form, or in cooking oils and other medicinal oils such as flaxseed oil, canola oil, soybean oil, and possibly olive oil, it depends on the manufacture and it would be listed on the content label. The NIH website lists all the foods and oils high in omega 3’s. They do not list olive oil even though it is the main stable of the Mediterranean diet which has amazing health and longevity effects.
Lu Y, Chen RG, Wei SZ, Hu HG, Sun F, Yu CH. Effect of omega 3 fatty acids on C-reactive protein and interleukin-6 in patients with advanced non-small-cell lung cancer. Medicine (Baltimore). 2018;97(37):e11971. doi:10.1097/MD.0000000000011971