B vitamins bestow heartfelt benefits.

Many studies in recent years have indicated that people who have high concentrations of the amino acid homocysteine in their blood face an increased risk of heart disease. The important role played by several B vitamins--notably folate and [B.sub.6]--in breaking down this amino acid has led to a suspicion that diets rich in these vitamins protect the heart. Two new studies now offer strong support for this argument.

In one, Eric B. Rimm and his coworkers at the Harvard School of Public Health in Boston tallied 658 heart attacks and 281 deaths from heart disease over 14 years among 80,000 women enrolled in the ongoing Nurses' Health Study. Using detailed information on the women's eating habits that had been collected at the start of the study, Rimm's group compared the amount and kind of B vitamins in the diets of women with heart disease to those of the other participants.

Orange juice, broccoli, vegetables, and eggs are good natural sources of folate. Since Jan. 1, breads, rice, and pasta have been fortified with folate. Meat, potatoes, whole grains, chicken, and bananas provide [B.sub.6] In the Feb. 4 Journal of the American Medical Association, Rimm's team reports that for each 200 micrograms ([micro]g) of folate consumed daily, a woman's heart disease risk falls by 11 percent--even after accounting for other risk factors. Similarly, heart disease risk dropped 17 percent for each 2-milligram increase in daily [B.sub.6] consumption.

In fact, Rimm says, to cut heart disease risk, "daily vitamin intake of folate and [B.sub.6], ought to be higher than the current recommended daily allowance (RDA)," which for these women is 180 [micro]g of folate and 1.6 mg of [B.sub.6]. Women who consumed at least twice the RDA of each vitamin--with or without the aid of multivitamin supplements--faced the lowest risks. For them, Rimm notes, "heart disease risk was almost cut in half."

A multinational European study, published in the Feb. 10 Circulation, finds that even in men and women with normal homocysteine concentrations, low [B.sub.6] consumption increases the risk of heart disease and stroke. Indeed, it found, people who were not getting the RDA of this vitamin faced almost twice the heart disease and stroke risk of those who ate recommended levels.