Since 1994, sales of vitamins and other dietary supplements have soared by well over 50 percent and are estimated to have topped $17 billion annually. One recent study found that up to 70 percent of Americans use vitamins, herbs, and other supplements. What’s curious about this is that there is very little evidence that such supplements have any effect on heart disease.

Vitamin E is a good example. Available in vegetables, oils, and nuts, vitamin E is a valuable source of antioxidants. But while magazines, newspapers, and even some doctors have touted vitamin E as “extra insurance” against heart disease, studies involving more than 60,000 people have failed to demonstrate that vitamin E has any effect on the heart at all.

What’s more, taken in high enough doses, vitamin E may adversely affect heart disease patients who are taking warfarin (brand name: Coumadin) as a blood thinner. (Taking warfarin at the same time as taking vitamin E in doses up to 400 units per day appears to be safe.) Folic acid (folate) and vitamin B supplements have also been promoted as being good for your heart.

There is an amino acid in your blood called homocysteine that, at high enough levels, has been associated with an increased risk of heart disease and stroke. Folic acid and, to some extent, vitamins B12 and B6 can lower homocysteine levels in your bloodstream.

But it hasn’t yet been proven that lowering homocysteine levels has any value for protecting your heart. Early studies suggested that taking folic acid and B vitamins after undergoing angioplasty (a procedure done to open up blocked arteries) helped keep those arteries from closing off again, but clinical trials have failed to show any specific heart-protecting benefits from either folic acid or vitamin B supplements.

Moreover, since enriched-grain products are fortified with folic acid, and vitamins B12 and B6 are readily available in meats, dairy products, beans, and grains, anyone following a balanced diet will have little need for supplements. Some studies have suggested that taking a multivitamin daily may reduce the risk of heart disease and stroke.

But this effect may be caused by people who take multivitamins tending to lead healthier lifestyles at the outset. Or it may be that multivitamins benefit heart health only in people who have nutritional deficiencies. Up to this point, there has been no compelling evidence in favor of taking multivitamins for your heart.

So if you’re following a balanced diet, you most likely don’t need them. Finally, a number of herbal remedies have been promoted to help treat hypertension, lower cholesterol, or protect against heart disease. These include coenzyme Q (ubiquinone), danshen, dong quai, garlic, ginger, ginkgo, ginseng, hellebore, and hawthorn (crataegus species).

New clinical studies are under way to examine these claims, but as yet there are no reliable research data to demonstrate that any of these alternative medicines have any significant effect on the heart—good or bad.

What do the guidelines say? The U.S. Preventive Services Task Force, an expert group funded by the government, recently conducted a comprehensive review of the medical literature relating to the use of vitamin supplements for cancer and cardiovascular disease prevention.

They concluded that the evidence is insufficient to recommend for or against the use of vitamins A, C, or E, multivitamins with folic acid, or antioxidant combinations for the prevention of heart disease (or cancer). They specifically recommended against supplements containing beta carotene. A recent review concluded that vitamin E has no effect.