One of the major changes in the Western diet over the last century has been the increase in our consumption of omega-6 fatty acids, primarily in the form of industrial seed oils. Examples include oils derived from soybeens, corn, and rapeseed (canola oil). Omega-6 fatty acid consumption in the U.S. increased by 213% since 2009. This may have important implications for development of certain chronic diseases like cancer and heart disease. Excessive omega-6 consumption may be harmful. On the other hand, omega-3 fatty acid consumption may prevent or mitigate the damages. Hence, the omega-6/omega-3 ratio becomes important.
I haven’t studied this issue in great detail but hope to do so at some point. Evelyn Tribole has strong opinions on it; I may get one of her books.
I saw an online video of William E.M.Lands, Ph.D., discussing the omega-6/omega-3 ratio. He mentioned free software available from the National Insitutes of Health that would help you monitor and adjust your ratio.
You can see the video here. Dr. Lands’ talk starts around minute 12 and lasts about 45 minutes. He says it’s just as important (if not more so) to reduce your omega-6 consumption as to increase your omega-3. And don’t overeat.