I have been eating tilapia for years and recently read an article in the NY Times that claimed farmed tilapia is high in omega 6, which have been known to cause certain health problems in humans. It was said this was due the composition of the fish feeds used, which contained high levels of corn and soy, that tipped the omega 3 to 6 levels. If they were to change the composition of the feeds, how would they do this and what ingredients would be necessary to increase the omega 3 levels?
The problem is that commercially produced fish feed tend to include ingredients that are not a component of a fishes normal diet. In the case of Tilapia they would normally feed on algae and plant life, which in turn would lead to a more balanced composition of Omega 3 and 6. In a commercial farming environment other sources of Omega 3 could be added to their diet such as walnuts of flax seeds. Whether this would be cost effective for the fish farmers is another thing, but it would certainly help change the nutritional composition of the fish.