A crucial part of a healthful diet is the ratio of omega-6s to omega-3s. Your immunity is supposed to be good for you by killing gems before they can harm you. However, if your immunity stays active, it starts to attack your own body to increase risk for heart attacks, certain cancers and even asthma and some types of arthritis. Omega-3 fatty acids produce prostaglandins that turn down your immunity to help prevent inflammation and the health problems it can cause. Omega-6 fatty acids promote inflammation. A major explanation for the high heart attack rate in North Americans is the high ratio of omega-6s to omega-3s in the diet that contains lots of omega-6s from vegetable oils and low amounts of omega-3's found in fish and seeds.
Few species of fish can grow and thrive on a diet of corn and plant oils. Salmon, trout and most other farmed fish must be fed fish meal and fish oils, which are good sources of omega-3's. However, tilapia and catfish can be raised on corn alone. Since corn-fed tilapia are inexpensive and abundant, they are the fifth most popular fish in America and are widely used for fish sticks, fish burgers and artificial crab (surimi). These are perfectly good foods, but to get the full benefit of omega-3's in seafood, choose oily fish such as salmon, trout, tuna, sardines, anchovies, mackerel or herring. More on omega-3's