Thus, oat products are allowed to bear a heart-healthy claim. Recently the FDA allowed soy foods to carry a heart-healthy claim if they contain a fair amount of soy protein and are eaten as part of a diet low in saturated fat and cholesterol. The benefit is usually modest, and may be significant only when soy protein replaces animal protein. Studies on flax have had inconsistent results, in fact, regarding cholesterol. This may help lower blood cholesterol, but it is not the only oil to do so.
Some studies give the edge to highly monounsaturated fats, such as olive oil.
Some early studies did find that fatty fish lowers cholesterol, but later ones have disputed this. But the same would happen if you replaced the meat with beans or other foods low in saturated fat. When researchers control for saturated fat intake, the effect of fish on cholesterol often turns out to be minimal, at best. Fish can, however, lower triglycerides, the major type of fat that circulates in the blood. And there are other ways that fish helps keep your heart healthy.