The soluble fibers contained in oats, for instance, have been shown to have a substantial impact on cholesterol levels when added to a low-fat diet. Other foods high in soluble fibers are lentils, pinto beans, citrus, black beans and barley.
For those people (and you know who you are) that prefer taking medical products instead of eating healthy food, psyllium (the fiber found in Metamucil,) has also been demonstrated to cause a significant reduction in cholesterol levels (but tragically, only in conjunction with a low-fat diet).

