Fiber Nothing could be less glamorous than fiber, which is, after all, just the indigestible part of fruits, vegetables and grain. But over the past 20 years, researchers have amassed an impressive array of evidence that fiber helps prevent colon cancer. For more fiber, eat high fiber cereal, bran flakes, rye crisp crackers, popcorn, toasted wheat germ, granola, high-fiber bread and beans. This soybean substance may lower the risk of a host of diseases including breast cancer because soy contains flavonoids, which are a source of phytoestrogen, a substance which chemically resembles estrogen. Researchers speculate this chemical may block receptor cells which can promote cancer.
Soy sauce is salty, though, so use it sparingly.