Remember the oat bran craze? In the late 1980s, several published studies touting the benefits of oat bran for lowering cholesterol had health professionals singing its praises.
Food companies were only too happy to accommodate the newfound demand, trotting out oat bran garlic bread, oat bran muffins, oat bran animal cookies, oat bran brownies, even oat bran-dusted potato chips and doughnuts.
Research in the 1980s focused mostly on the effects of the bran, but over time, the focus shifted to the benefits of whole oats. And by 1997, the cholesterol-lowering evidence for oats was so strong that the Food and Drug Administration approved the first "food-specific claim," permitting labels of oat-rich products to bear a statement that eating oats and oat-based foods reduced the risk of cardiovascular disease. (Up until then, only nutrient-specific claims -- such as for reduced fat or salt -- had been given FDA approval.)
Findings on food and health sometimes swing back and forth like a pendulum. But in the 10 years since that claim was allowed, continued research into the reported benefits of oats has verified the link and offered new insights into how oats help the heart.
Regular oatmeal consumption lowers total cholesterol as well as "bad" -- LDL -- cholesterol, with no adverse effects on the "good" -- HDL cholesterol. It also has the potential to reduce inflammation, one of the first steps in the development of atherosclerosis.
Most studies point to beta-glucan -- the soluble fiber in oat bran that gives cooked oats their gluey texture -- as the likely active agent in cholesterol reduction. Part of the mechanism has to do with bile, a cholesterol-rich fluid that helps the body digest fats. Beta-glucan increases the excretion of bile from the gall bladder into the small intestine. This, in turn, stimulates the body to produce more bile -- pulling cholesterol out of the blood to do so.
Whole oats also contain polyphenols, a class of antioxidant compounds found in all kinds of plant foods (including berries, tea, wine and chocolate) that may play an additional role in keeping the heart healthy. Avenanthramides, polyphenols unique to oats, have been shown -- at least in a cell culture dish -- to interfere with inflammation, a key step in the development of arterial plaque.
