Folic Acid May Not Aid Heart Patients
More Evidence Against Role for Vitamins in Cardiovascular Disease
June 17, 2003 -- It's looking less and less like vitamin therapy is a major player in protecting against heart disease. Heart patients who took folic acid fared no better than those who did not in one of the first clinical trials evaluating the vitamin's role in cardiovascular disease.
The findings come less than a week after another study found that the antioxidant vitamins E and beta-carotene provided no clinical benefit in patients with a history of heart problems. Patients who took beta-carotene supplements actually had a slightly increased risk of death.
"I think it is fair to say that the hope of vitamin therapy for the prevention and treatment of cardiovascular disease has to date not been borne out by the randomized evidence," heart disease researcher Charles H. Hennekens, MD, tells WebMD. "But it is premature, based on this small trial, to say that folic acid isn't protective."
Studies showing that folic acid lowers blood levels of the amino acid homocysteine raised the hope that the inexpensive vitamin can help prevent and treat heart disease. People with high homocysteine levels are at increased risk for heart disease and death, but it is not clear if lowering these levels reduces this risk.
In this study, researchers in the Netherlands recruited about 600 patients with a history of heart attacks or narrowing of the arteries who were already on statin therapy to lower their cholesterol. Half of the patients were also treated with low-dose folic acid and the other half were not. The findings are published in the latest issue of the Journal of the American College of Cardiology.
After two years of treatment, homocysteine levels were reduced by 18% in the patients taking folic acid. Homocysteine levels were not reduced in the patients not treated with the vitamin, but no significant difference was seen between the two groups in the incidence of heart attacks, strokes, treatment for artery blockage, and death.
Lead author Anho Liem, MD, says homocysteine levels may be merely a marker, or symptom, of cardiovascular disease instead of a cause, in the same way that fever is a symptom of pneumonia.
"Homocysteine is important, but correcting it doesn't necessarily mean that the patient gets better," he tells WebMD. "Many cardiologists once recommended vitamin E to patients, but it appears that it doesn't do much. Now many are recommending folic acid, and it may prove to be the same story."
Liem and Hennekens agree that the early findings must be confirmed in larger trials. Three such trials are now under way, and results are expected within three to five years. In the meantime, Hennekens says, patients should not ignore the many proven therapies for the prevention and treatment of heart disease.
"There are people out there who are taking folic acid and other vitamins for their heart, but they aren't taking aspirin, statins, beta-blockers, or ACE inhibitors," he says. "We have proof beyond a reasonable doubt that these treatments work. By focusing on unproven treatments, we may be decreasing the likelihood that people will take the drugs that are of proven benefit."