Over the years, omega-3s have been stripped from the foods we eat. Where have they gone? Blame it on altered eating habits:
Hydrogenation of oils in food processing
Decreased fish consumption
Loss of cereal germ in modern milling practices
Increased consumption of corn, sunflower and sesame oils
Increased sugar consumption, which interferes with enzymes that synthesize fatty acids
Increased consumption of trans-fatty acids, such as margarine and deep-fried foods
Source: The Omega Plan (HarperCollins Publishers) by Artemis Simopoulos, MD, and Jo Robinson.