It’s all about diet. The chickens that produce omega-3-enriched eggs are fed a special diet including lots of flaxseed, whose oil is about 55 percent alpha-linolenic acid (ALA). That’s one of the three omega-3 acids that research shows may have cardiovascular benefits. Free-range chickens that eat grasses and bugs also tend to lay eggs with higher omega-3 content than those fed corn or soy, but eggs labeled “omega-3 enriched” are fed a more flaxseed-intensive diet. A normal egg contains about 80 mg of ALA, while an enriched one has over 200 mg. The Institute of Medicine recommends 1.6 g per day of ALA for men and 1.1 g for women.