Human studies continue to demonstrate powerful benefit from EPA and DHA for individuals with arthritis, inflammatory bowel disease, asthma, and a variety of other autoimmune diseases. These conditions are clear examples of Omega-3 fatty acids positively impacting immune function.
The impact of EPA and DHA on immune function also explains much of the benefit EPA and DHA have in other areas of health, notably cardiovascular health and emotional well being. How is immune function affected by EPA and DHA? How do these effects impact cardiovascular health, emotional well being, and inflammation?
Dietary fats provide the building blocks for hormone-like molecules produced by cells of the immune system. These hormone-like molecules (cytokines) provide the means by which the immune system communicates with itself, as well as with other body tissues. Historically humans consumed a diet which delivered equal proportions of Omega-3 and Omega-6 fatty acids. Modern North American society consumes a diet which contains approximately 20 times more Omega-6 fat relative to Omega-3 fat. This profound difference in dietary fat selection has powerful impact on the function of the human immune system.
Cytokines made from the Omega-6 fat arachidonic acid (AA) are considered pro-inflammatory. An overproduction of cytokines from AA results in worsening of conditions such as arthritis, inflammatory bowel disease, asthma, psoriasis, eczema, and others. Omega-3 fatty acids can also give rise to cytokines. The cytokines produced by Omega-3 fatty acids (specifically eicosapentaenoic acid, EPA) act in the opposite manner as AA-derived cytokines. Not surprisingly, human studies have shown that fish oil supplementation benefits numerous conditions. Consuming more Omega-3 helps to shift the balance towards improved health.