What is homocysteine?Homocysteine (Hcy) is an amino acid produced in our bodies when we break down methionine (Met). Met is found in relatively large amounts in animal proteins (eggs, dairy and meats). Elevated levels of Hcy in the blood increase not only the risk of cardiovascular disease, but are a strong predictor of mortality in patients with confirmed coronary artery disease, according to over 75 studies. A recent Wall Street Journal article said that elevated levels of Hcy make the walls of your arteries like sandpaper instead of teflon. Actually, the mechanism by which increased Hcy contributes to atherosclerosis is still being worked out, but an increased tendency for blood to clot, and direct damage to the lining of the arteries, are likely.What elevates Hcy levels?Most people have elevated Hcy levels due to a lack of one or more B-vitamins (Vitamins B-6, B-12 and Folate). Low levels of any one of these vitamins can result in substantial elevation of Hcy and an increased risk of cardiovascular disease.Is Hcy a more important risk factor for coronary heart disease than serum cholesterol?Probably not for most people. The MRFIT study found a 4-fold increase in fatal heart attacks in men who had a cholesterol level above 245 compared to those whose levels are below 185. A Hcy level above 15.8 is associated with a 3-fold increase as compared to a level of 10 or less. While a high Hcy level is less risky than a high cholesterol level, an elevated Hcy level is about as risky as either cigarette smoking or high blood pressure in terms of increasing the risk of cardiovascular disease.Should everyone get their serum Hcy level checked just like their serum cholesterol level? I would say yes, but the test costs $30-130, depending on your locale, and may not be covered by insurance. In addition, most labs are not equipped to test for Hcy so you may have trouble finding a doctor to do the test.What can you do to keep your homocysteine level low or to lower it if it is high?The first thing you can do is to improve your diet. Beans, whole grains, oranges and dark green vegetables are all good sources of folate - the vitamin found most often to be in short supply in people who have elevated Hcy.Eating more beans and less meat and cheese not only lowers your Hcy levels, but also lowers your LDL (bad cholesterol). Some people, who eat healthy but still have elevated levels of Hcy, can benefit from taking B Vitamin supplements, but they should talk to their physician and/or a registered dietitian first.According to Dr. R. J. Barnard, researcher at UCLA, animals fed a diet high in fat and sugar produced more Hcy in their livers and had higher plasma Hcy levels. Both elevated serum LDL (bad cholesterol) and Hcy increase the risk of cardiovascular disease and can be lowered by a lowfat diet with plenty of fruits, whole grains, vegetables and beans and only modest amounts of nonfat dairy and fish and little or no poultry and lean meat.The growing evidence that elevated Hcy is an important risk factor for heart disease simply provides more evidence that a lowfat, more vegetarian diet is the key to preventing and treating cardiovascular disease.By James J. Kenney, PhD, RD, FACN.