Researchers at the University of Wisconsin have found that beef and cheese contain a cancer-fighting compound called conjugated linoleic acid. A quarter pound of ground chuck, for example, contains millions of times more CLA than it has mutagens.

On the other hand, alfalfa sprouts contain a potent natural carcinogen called canavanine. Esquire reports that in a test to determine the effects on monkeys of a diet high in alfalfa sprouts, one-third of the animals developed autoimmune disorders and other significant abnormalities.

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