Oats contain soluble fiber that's been shown to help lower blood cholesterol. But two studies show that fiber may be only part of the health benefits contained in this common grain.

Until recently, scientists believed that it was the beta-glucan contained in the soluble fiber found in oats that was responsible for their cholesterol-lowering effect. While beta-glucan plays a part in this process, it's not the whole story.

Like fruits and vegetable, oats also contain phytochemicals, which are naturally occurring chemicals in plants that help fight disease. Oats, in particular, have lots of flavonoids. These are powerful antioxidants that help prevent heart disease and cancer.