Folic Acid Reduces Heart Disease Risk

June 11, 1997

Contact:
Mary Burnette
202-872-1488

FOLIC ACID REDUCES HEART DISEASE RISK

A new study published in the June 11 Journal of the American Medical Association (JAMA) reinforces growing evidence that high blood levels of homocysteine, an amino acid, can increase the risk of heart disease as much as smoking or high cholesterol. Moreover, the study also suggests that people who supplement their diets with folic acid and other B vitamins, which are known to lower homocysteine levels, experience substantial protection from vascular disease.

Researchers, led by a team at Trinity College in Dublin, Ireland, said that "We believe it is time to consider whether existing recommended daily allowances of the vitamins that modulate homocysteine metabolism are adequate, and to undertake randomized controlled trials of the effects of folic acid and perhaps pyridoxine (B-6) in the secondary prevention of cardiovascular disease." They also recommend that physicians check their patients' homocysteine levels as part of total vascular disease risk assessment.

The study involved 1550 male and female subjects from 19 European medical centers. Researchers found that those with homocysteine levels in the top 20 percent of the study group doubled their risk for heart disease. Users of supplements containing folic acid, cobalamin (B-12), or pyridoxine (B-6) reduced their risk by 60 percent compared to those who did not take supplements. The researchers state that "elevated plasma homocysteine level is now established as a strong and independent factor associated with all categories of atherosclerotic (heart) disease in both men and women." Moreover, high blood levels of the amino acid were found to increase further the risk of vascular disease for smokers and those with high cholesterol, said researchers.

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Folic Acid/Heart Disease Risk 2-2-2-2

This latest study confirms the results of a number of earlier findings. A study published in the June 26, 1996, Journal of the American Medical Association reported a 70 percent increase in the risk of death from coronary heart disease in people with low serum folate levels, compared to people in the highest quartile of serum folate levels. Authors of that JAMA article encouraged people to eat more fruits and vegetables to increase their folate intake but they added "not all people will increase their dietary consumption of folate and the bioavailability of folate from food is significantly less than that from folic acid supplements."

A meta-analysis conducted at the University of Washington and published in the October 5, 1995, JAMA estimated that there could be as many as 56,000 folic acid-preventable deaths from heart disease annually. Study director Shirley Beresford and co-authors said, "A strong case can be made for...increased folic acid intake [that] could prevent arteriosclerotic vascular disease."

All of these studies add to the already substantial evidence that the current Recommended Dietary Allowance (RDA) for folate is much too low (200 mcg per day for men, and 180 mcg per day for women). The RDA for folic acid should be raised substantially, in order to establish a more realistic target level for optimal intakes to reduce heart disease risk.

In an editorial accompanying the June 26, 1996 JAMA, article, Drs. Meir Stampfer and Eric Rimm, of the Harvard School of Public Health, observed that the optimal amount of folic acid supplementation has not been defined. They suggest that 650 mcg per day has been shown to lower serum homocysteine levels and note that 400 mcg per day is "probably" sufficient. The researchers point out that about 88 percent of Americans get less than 400 mcg per day of folate from their diets.

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