April 15, 2010 -- Foods rich in B vitamins such as folate and B-6 may reduce the risk of death from stroke and heart problems, Japanese researchers say.
Their study looked at the effects of B vitamins on men and women separately, but findings suggest that foods containing the B vitamins might benefit people of both sexes.
Their primary findings:
- Folate and B-6 may reduce the risk of heart failure in men.
- The same vitamins seem to reduce the risk of death from stroke and heart disease in women.
Sources of folate include vegetables, fruits, whole or enriched grains, fortified cereals, beans, and legumes. B-6 sources include fish, vegetables, liver, meats, whole grains, and fortified cereals.
Vitamin B6, Folate Fight Heart Disease
The researchers examined data from 23,119 men and 35,611 women between ages 40 and 79 who completed questionnaires about dietary habits as part of the Japan Collaborative Cohort Study.
Patients were divided into five groups based on their intake of folate, vitamin B6, and vitamin B12. Researchers compared people with the diets lowest and highest for each nutrient and found that higher consumption of folate and B6 was associated with significantly fewer deaths from heart failure in men. In women, they detected significantly fewer deaths from stroke, heart disease, and total cardiovascular deaths.
Vitamin B12 was not found to be associated with a reduced risk of mortality.
The protective effects of folate and vitamin B6 did not change even when researchers made adjustments for the presence of cardiovascular factors or when people taking supplements were eliminated from the analysis.
The researchers say the findings on the value of B vitamins were consistent with studies in North America and Europe. Homocysteine is believed to cause damage to the inner linings of arteries, promoting blood clots.
B Vitamins: More Research Needed
Hiroyasu Iso, MD, professor of public health at Osaka University and one of the study authors, says in a news release that people in Japan need to increase consumption of foods containing folate and vitamin B6.
The researchers say the correlation between intake of folate and B vitamins with cardiovascular disease is controversial and that evidence of benefits has been limited to Asian populations. Given their findings, the researchers say there is an urgent need for more research aimed at replicating the results of their study in different populations.
The study is published in the April issue of Stroke: Journal of the American Heart Association.
The Institute of Medicine (IOM), the health arm in the U.S. of the National Academy of Sciences, recommends 1.3 to 1.7 milligrams of vitamin B6 per day, depending on age and sex. The IOM says extremely high-dose folate supplements should be avoided and recommends adult intake of 400 micrograms daily.