Eating more foods containing the B vitamins folate and B6 lowers the risk of death from stroke and heart disease for women and may reduce the risk of heart failure in men, according to Japanese research. “Japanese people need more dietary intake of folate and vitamin B6, which may lead to the prevention of heart disease,” said Hiroyasu Iso, professor of public health at Osaka University.
The findings on the value of B vitamins were consistent with studies in Europe and North America, although the dietary consumption of vitamin B6 is generally lower in Japan than in the United States.
Researchers analyzed data from 23,119 men and 35,611 women (ages 40-79) who completed food frequency questionnaires as part of the large Japan Collaborative Cohort (JACC) Study. During a median 14 years of follow-up, 986 died from stroke, 424 from heart disease and 2,087 from all diseases related to the cardiovascular system.
Investigators divided participants into five groups based on their intake of folate, vitamin B6 and vitamin B12. Comparing those with the diets lowest and highest for each nutrient, they found that higher consumption of folate and vitamin B6 was associated with significantly fewer deaths from heart failure in men, and significantly fewer deaths from stroke, heart disease and total cardiovascular diseases in women. Vitamin B12 intake was not associated with reduced mortality risk.
Image: A ball and stick model of folic acid, also known as folacin or vitamin B9.
The protective effects of folate and vitamin B-6 didn’t change when researchers adjusted for the presence of cardiovascular risk factors, nor when they eliminated supplement users from the analysis.
Folate and vitamin B-6 may help guard against cardiovascular disease by lowering homocysteine levels, the investigators said. Homocysteine is an amino acid in the blood that’s affected by diet and heredity. Folic acid and other B vitamins help break down homocysteine in the body.
A direct causal link hasn’t been established, but evidence has shown that too much homocysteine may damage the inner lining of arteries and promote the formation of blood clots.
Sources of folate include vegetables and fruits, whole or enriched grains, fortified cereals, beans and legumes. Sources of vitamin B-6 include vegetables, fish, liver, meats, whole grains and fortified cereals.
References:
1. Hiroyasu Iso, et al. Dietary Folate and Vitamin B6 and B12 Intake in Relation to Mortality From Cardiovascular Diseases. Japan Collaborative Cohort Study. Stroke, Apr 2010; doi:10.1161/STROKEAHA.110.578906
