Archived NutriNews

Omega–3 fatty acids are polyunsaturated fatty acids that are essential for the proper structure and function of multiple body systems and include eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which can be obtained from oils derived from salmon, tuna, mackerel, anchovies, and sardines as well as other fish. Omega–3 fatty acids have been widely studied for numeroushealth benefits, and research has been generating volumes of positive data. In addition to many other positive effects, studies have shown that DHA and EPA play an important role in cardiovascular health, and a consistent theme that has emerged from the literature on omega–3 fatty acids is their strong support of inflammation. There are mostly likely multiple anti–inflammatory mechanisms at work to explain the actions of omega–3 fatty acids. EPA and DHA have demonstrated the ability to inhibit the formation of pro–inflammatory compounds derived from arachidonic acid (AA) and shift the balance more toward the production of anti–inflammatory compounds. Studies have shown an inverse correlation between blood levels of omega–3 fatty acids and CRP levels, and supplementation with omega–3 fatty acids has resulted in the reduction of CRP. Recent research has also demonstrated that omega–3 fatty acids may exert a direct effect by interacting with a receptor located on fat cells known as GPR120.

I typically recommend 2–12 grams of EPA/DHA for support of inflammatory processes. To support neurological health I usually recommend 2–4 grams in divided doses, while similar or higher doses may be needed for cardiovascular helath. Consider 4–12 grams to help support autoimmune health as well as musculoskeletal health.

Controversy has continued to linger over what form of fish oil is best absorbed. Many of the clinical studies in the literature have used fish oil in the form of ethyl esters and have shown beneficial effects on health; however, data continues to emerge showing that the natural triglyceride or re–esterified triglyceride form is better absorbed. Two recent placebo-controlled studies have helped to highlight this fact. In one study, the researchers measured the omega–3 index in subjects after supplementation with either an ethyl ester or a re-esterified triglyceride. At the end of both three and six months, the group consuming the re-esterified triglyceride had a significantly higher omega–3 index compared with the group consuming the ethyl esters. In another study, subjects were supplemented with numerous forms of omega-3 fatty acids, including ethyl esters, natural triglycerides, and re-esterified triglycerides. After two weeks, subjects consuming the re–esterified triglycerides had the highest blood level of EPA and DHA. Another area of interest with respect to omega–3 fatty acids is the method used to extract and concentrate the oil. The traditional method that is used to create concentrated oil is a process called molecular distillation. In this process, the oil is subjected to repeated rounds of elevated temperature in the presence of a vacuum to help concentrate and purify the oil. Oils manufactured in this manner are quite acceptable and can yield good products. More recently, a technology called supercritical CO2 extraction is making its way into the spotlight. Supercritical fluid extraction involves using CO2 (carbon dioxide) in its supercritical state as a medium to gently extract and concentrate EPA and DHA from the other components of the oil. In its supercritical state, CO2 behaves both like a liquid as well as a gas. EPA and DHA are both soluble in supercritical CO2; however, unwanted components of the oil including saturated fat, cholesterol and impurities are not soluble. This process eliminates the need for the more elevated temperatures used in molecular distillation and protects the oil from exposure to oxygen. Additionally, this method of purification and concentration is ecologically friendly, as it does not involve the use of hexane or ethanol, and the CO2 can be recycled many times. While popular in Europe, this technology is becoming more prevalent in the U.S. as a means of manufacturing highly purified omega–3 fatty acids.