Bookmarkers beware: Bookmarks to pages other than the home page may not work after we change our server in April Editor's Choice | This Week in BMJ | Press releases BMJ No 7130 Volume 316 News Saturday 14 February 1998 Vitamin B may reduce risk of heart disease Consuming high levels of vitamin B6 and folate may substantially reduce a woman's risk of coronary artery disease, according to study published in the journal of the American Medical Association (JAMA1998;279:359-64). The study, led by Dr Eric Rimm of the Harvard School of Public Health, is the latest in a series of recent investigations linking high levels of homocysteine with atherosclerotic plaque formation and occlusive vascular disease. The B vitamins are known to be involved in the metabolism of homocysteine. The researchers analysed data from over 80,000 women enrolled in the nurses health study. The women filled out a detailed questionnaire and were classified into five groups on the basis of the amount of vitamin B6 and folate consumed. They were then followed and re-evaluated periodically for 14 years. During that time 658 of the women had non-fatal heart attacks and 281 died of myocardial infarctions. Women who consumed the most folate (700 µg a day) were 31% less likely to have a heart attack than those in the group taking least folate. Similar results were found with vitamin B6 - those who consumed high levels (4.6 mg a day) were 33% less likely to have infarctions than the lowest consumers of vitamin B6. A synergistic effect was seen in those who consumed high levels of both vitamin B6 and folate. This group reduced their coronary risk by 45%, suggesting independent mechanisms of coronary protection afforded by these vitamins. The greatest risk reduction was seen in nurses who consumed moderate amounts of alcohol and high levels of B vitamins. This group experienced a risk reduction of 75%. Alcohol is known to increase levels of high density lipoproteins, which in turn are thought to protect against heart disease. However, Dr Ronald Kraus, chairman of the nutrition committee of the American Heart Association, said that the study should be interpreted cautiously because it was questionnaire based and relied on participant recollections. In an accompanying editorial Dr Kilmer McCully from Rhode Island, states that the research will need further investigation, particularly because of the confounding factor of alcohol - alcohol by itself reduces levels of serum folate. The observation that a high level of homocysteine is associated with atherosclerosis dates from the 1950s, but it was largely ignored in the wake of the association between cholesterol and heart disease and the advent of cholesterol lowering drugs. Its rediscovery is exciting because it represents a potentially easily reversible risk factor for coronary artery disease. The study's authors suggest that the current recommended daily allowances for folate and vitamin B6 should be increased to provide cardiac protection. "Our results suggest that any widespread increase in folate intake will have a favorable impact on coronary heart disease rates, but that the maximum benefit would be achieved with a folate intake of at least 400 µg a day," the researchers conclude. The recommended daily allowance for folate is currently 180 µg a day. Folate is found in fortified cereals, orange juice, bananas, whole grains, spinach and other leafy greens. Deborah Josefson San Francisco Home | Current issue | Past issues | Classified ads | Career Focus | Feedback Collections | About this site | About the BMJ | BMA | Medline