B Vitamins Cut Heart Disease Risk for Women

By William J. Cromie

Gazette Staff

Women can cut their risk of heart disease in half by taking more B vitamins, according to a study done at the School of Public Health.

Roughly doubling the recommended daily allowances of folic acid and vitamin B6 protects the heart's arteries from developing potentially fatal blockages, Harvard researchers reported yesterday in the Journal of the American Medical Association.

"We were surprised to see that for women with the highest intake of both vitamins, heart disease risk was almost cut in half, compared to women with low intake of both," says Eric Rimm, lead author of the report and assistant professor of epidemiology and nutrition.

The study was done by having 80,082 nurses fill out medical questionnaires about their diet, lifestyle, and current health status. During 14 years of followup 281 of them died of heart disease and 658 had heart attacks.

Men will probably get the same benefits from these vitamins as women. "We are doing a study of 50,000 men, and our preliminary results are almost identical," Rimm said in an interview.

The biggest contributors to intake of folic acid, part of the group of B vitamins, included cold cereal, orange juice, lettuce, eggs, broccoli, spinach, and multivitamin pills. B6 was most plentiful in beef, cold cereal, potatoes, bananas, chicken, milk, tuna fish, and multivitamin pills.

"Our findings suggest that daily intake of these two vitamins ought to be higher than current recommended daily allowances," Rimm comments.

Current dietary recommendations for women call for 180 milligrams a day of folic acid (also known as folate), and 1.6 milligrams of B6. Rimm and his colleagues found the lowest risk of heart disease occurred with at least 500 milligrams of folic acid and 3 milligrams of B6 a day,

"We believe that any widespread increase in folate intake will have a favorable impact on coronary heart disease rates, but the maximum benefit would be achieved at an intake of at least 500 milligrams a day," Rimm notes.

Women who got the most benefit were moderate drinkers of alcohol. Other research has shown that women who drink one glass of beer, wine, or spirits a day have less risk of heart disease than those who do not drink. And several studies at Harvard concluded that men who consume one-two drinks a day reduce their heart attack risk by almost half, compared to non-drinkers.

Moderate intake of alcohol apparently works by raising levels of beneficial (high-density) cholesterol in the blood. Folic acid and B6 lower blood levels of homocysteine, a by-product of protein metabolism blamed for damaging artery walls and aiding formation of clots in heart arteries.

"With moderate alcohol consumption and high folate intake, you get an additive effect," Rimm noted. Woman who drank moderately and consumed high levels of the vitamins experienced an 80 percent reduction in heart disease, compared to non-drinkers with a low folic acid intake.

The Harvard researchers reach the obvious conclusion that recommended daily allowances for folic acid and B6 should be raised.

An editorial in the same issue of the Journal emphasizes this conclusion. "These results support the view that current recommended daily allowances are too low to provide optimal protection against cardiovascular disease, and [they] need to be revised accordingly," writes Kilmer McCully from the Department of Veterans Affairs Medical Center in Providence, R.I. McCully is a longtime proponent of the idea that homecysteine is a major cause of heart disease, and that its toll can be reduced by diets high in the B vitamins.