Heart association removes folic acid for prevention

The 2007 Guidelines for Preventing Cardiovascular Disease in Women, published today in a special women's health issue of the Journal of the American Heart Association, include recommendations for using aspirin, hormone therapy and dietary supplements in heart disease and stroke prevention in women.

There has been controversy in past on whether or not folic acid plays a role in heart disease prevention, and this AHA verdict represents a strike against a vitamin for which a significant number of studies have shown favorable results.

"The new guidelines reinforce that unregulated dietary supplements are not a method proven to prevent heart disease," said Lori Mosca, director of preventive cardiology at New York–Presbyterian Hospital and chair of the American Heart Association expert panel that wrote the guidelines.

"For example, recent studies have shown that folic acid is ineffective to protect the heart despite widespread use by patients and physicians hoping for a heart benefit."

The Council for Responsible Nutrition (CRN) disagrees with AHA's stance on folic acid and antioxidant supplements.

"It's a little odd that they would recommend to not use these supplements for primary or secondary prevention when really the jury is still out for primary prevention," Andrew Shao, CRN Vice President of Scientific & Regulatory Affairs, told NutraIngredients-USA.

"We disagree with the wording and feel it might cause people to stop taking their supplements."

Studies have linked increased blood levels of the amino acid homocysteine to an increased risk of cardiovascular disease.

It has been suggested that by lowering levels of homocysteine in the blood, people could cut the risk of cardiovascular disease.

A meta-analysis published in November's Journal of the American Medical Association , found folic acid had no effect on cardiovascular disease among people with existing vascular disease.

Whereas in November, a review from the British Medical Journal determined evidence supporting folic acid's role in heart health was enough for the vitamin to be recommended.

"Since folic acid reduces homocysteine concentrations, to an extent dependent on background folate levels, it follows that increasing folic acid consumption will reduce the risk of heart attack and stroke by an amount related to the homocysteine reduction achieved," wrote lead author David Wald.

Folate is found in foods such as green leafy vegetables, chick peas and lentils, and an overwhelming body of evidence links has linked folate deficiency in early pregnancy to increased risk of" neural tube defects (NTD) – most commonly spina bifida and anencephaly – in infants.

CRN also finds fault with AHA's claim that the dietary supplement industry is not regulated.

"This is a mistake that is often made but a mistake nonetheless," said Shao.

A recent American Heart Association survey showed that women are confused about methods to prevent heart disease including the role of dietary supplements, aspirin and hormones.

"These recent findings emphasize the importance of using well-conducted clinical trial data to develop national recommendations to help patients and their doctors use best practices to prevent heart disease – practices based on data rather than myth or wishful thinking," says the report.

The meta-analysis published in the Journal of the American Medical Association included data for 16,958 participants from studies that compared folic acid supplementation with either placebo for a period of at least six months and a maximum follow-up of five years.

Clinical cardiovascular disease events were reported as an end point.

Reviewing the evidence, Wald and his colleagues from the Wolfson Institute for Preventive Medicine, Barts and the London, Queen Mary School of Medicine and Dentistry report that while such randomized trials are important, they are not the only source of evidence.

Indeed, reviewing cohort studies led them to state that a three micromole per litre decrease in serum homocysteine levels, said to be achievable with a daily folic acid intake with 0.8 milligrams, lowers the risk of heart attack and stroke by 15 and 24 per cent.