It sets a bad precedent to focus on one food, as if it were a magic bullet. What this will do is encourage people to stuff themselves on oat bran products or oat products at the expense of some other good food.

But Weil is hardly an objective expert on supplements. The more supplements Weil can persuade consumers to buy, the more he benefits. Consumers should bear that in mind when they listen to his advice.

Either Larry King has a knack for picking weak products to pitch, or manufacturers seek him out to lend credibility to supplements that could use some.