You may have read my post on Epigenics and the role of B vitamins on diabetes gene suppression.
Here's a must-read article by Dr. Frank Lipman on how healthy food habits can "nurture genes" and bring out the best in them. The science is called 'Nutrigenomics'. In addition to him recommending to eat vegetables, fruits, nuts, and seeds, he also recommends trying to eat as close to nature as possible. For Omega3's, you can have flaxseed, salba, algae, walnuts, hemp seed and canola.