the heart of the matter - studies show link between blood homocysteine levels and risk for heart disease - Brief Article

Better Nutrition, Feb, 2001 by Abigail Chipley

Back in the 1950s, researchers first realized that a high level of cholesterol--found in fatty meats and other animal products--was a serious risk factor for heart disease. But recent findings suggest that it's more than just the fat in meat that's dangerous. Studies show that a high blood level of a substance called homocysteine, which is synthesized from an amino acid found in meat, dairy and eggs, also raises the risk for heart disease significantly. More than a dozen studies have found that people with even a moderately high blood level of homocysteine are three times more likely to suffer a heart attack or stroke than those with low levels.

Seventeen studies are currently under way to determine whether reducing homocysteine actually protects against heart disease, but the results won't be in for a few more years. Still, many doctors are already advising patients who are at risk to get their homocysteine level checked and to take steps to reduce it if it's even moderately high. "I have patients who are teetering on the edge of disease and don't have five years to wait for the results of these studies," says William Castelli, M.D., former head of the ongoing Framingham Heart Study and now director of the Framingham Cardiovascular Institute in Massachusetts.

While there are no drugs that act on homocysteine directly, research definitively shows that B vitamins--especially folic acid, [B.sub.6] and [B.sub.12]--help keep homocysteine from building up in the blood. A study published in the August 22 edition of Circulation found that participants who ate a diet rich in fruits and vegetables had higher levels of folic acid--and lower levels of homocysteine--than those who ate a typical, high-fat American diet lacking in adequate fruits and vegetables. Both folic acid and [B.sub.6] are abundant in green vegetables (like asparagus, broccoli, spinach and romaine lettuce) and in oranges, lentils and whole grains.

But for people who already have heart disease or who aren't able to significantly reduce their homocysteine levels even after changing their diets, Castelli recommends taking a daily B-100 complex supplement--which contains 100 milligrams (mg.) of riboflavin, niacin, and [B.sub.6], 400 mg. of folic acid and 100 micrograms of [B.sub.12]. A study published in the September issue of the Journal of the American College of Cardiology found that participants given 5 mg. of folic acid per day were able to reduce their homocysteine levels by 11 percent. That's a much higher dose than most people should take, however. Says Bassam Nassar, M.D., Ph.D., one of the lead authors of that study, "Patients should follow the recommendations of their physicians regarding dosages. The levels of supplementation that need to be achieved vary from one patient to another."