Omega-6 fatty acids, omega-3 fatty acids, which is better?
By David Liu, PHD
Monday July 30, 2012 (foodconsumer.org) -- Many savvy food consumers may have already known that the ratio of dietary omega-6 to omega 3 fatty acids is an important quality attribute of a person's diet. Ideally the ratio should be kept below 4, which could reduce the risk of cardiovascular disease by 75 percent compared to the ratio for the general American population although in reality the ratio for most American diets right now is greater than 15.
High ratios of omega-6 to omega-3 PUFAs can increase risk for diseases including cardiovascular disease, type 2 diabetes, obesity, metabolic syndrome,irritable bowel syndrome & inflammatory bowel disease, macular degeneration, rheumatoid arthritis, asthma, cancer, psychiatric disorders, and autoimmune diseases, according to Chris Kresser - a nutrition consultant.
E. Patterson of Alimentary Pharmabiotic Centre, Biosciences Institute, County Cork, Ireland and colleagues released a report online April 5, 2012 in Journal of Nutrition and Metabolism saying Omega-6 (n-6) polyunsaturated fatty acids (PUFA) such as arachidonic acid and omega-3 (n-3) PUFA such as eicosapentaenoic acid (EPA) are precursors to potent lipid mediator signalling compounds called eicosanoids which participate in the regulation of inflammation.
The authors say generally eicosanoids derived from n-6 PUFA are proinfammatory whereas eicosanoids from n-3 PUFA are anti-inflammatory. This could be that the ratio of n-6 to n-3 PUFA indicates a person's status of inflammation with a high ratio indicating a tendency to induce inflammation, leading to many inflammatory chronic diseases.
Patterson et al. pointed out that dietary changes over the past few decades in the intake of n-6 and n-3 PUFA resulted in an great increase in the ratio of the (n-6) to (n-3) ratio to 15 to 1, which is typical in the United States.
Coinciding with this increase are increases in chronic inflammatory diseases including nonalcoholic fatty liver disease (NAFLD), cardiovascular disease, obesity, inflammatory bowel disease, rheumatoid arthritis, and Alzheimer's disease.
The authors concluded "By increasing the ratio of (n-3) to (n-6) PUFA in the Western diet, reductions may be achieved in the incidence of these chronic inflammatory diseases."