India, Dec. 20 -- Flax seeds do not look like much. They are tiny, plain, easy to ignore. But they have been feeding people for centuries, long before they showed up in smoothie bowls and health-store shelves. In parts of the Middle East, these oil-rich seeds were everyday food, relied on for energy and nourishment. That has not changed. What has changed is how clearly we now understand what they do for the body.

People will find flax seeds sold in different forms - whole, ground, roasted, or pressed into oil. The form matters more than most people realise. Whole seeds often pass straight through the digestive system. Grind them, though, and the body can actually access what's inside, especially the fats locked beneath the tough outer sh...