When you reach for that bottle of ibuprofen to fight your headache, how do you know that it will work? More important, how do you know it won't kill you?

The answer is easy enough: scientists tested it for safety and effectiveness in rigorous, carefully designed clinical trials. Based on data from those trials, the U.S. Food and Drug Administration (FDA) approved ibuprofen for general use as a painkiller. The side effects had been identified and could be listed on the package.

But dietary supplements, substances such as vitamins and herbs, aren't subject to the same strict FDA oversight as drugs. As a result, just because a supplement appears on supermarket shelves doesn't mean that it has been proven effective, or safe, or that its side effects and interactions with prescription drugs are known.

Take the case of ginkgo biloba, an herbal supplement we first examined in the premiere issue of Memory Loss and the Brain. Dozens of studies suggest that ginkgo may be a memory booster and may even help treat or prevent Alzheimer's disease. Yet skeptics insist that the case is not proven: despite all those suggestive studies, we just don't know for sure whether ginkgo biloba is effective.

The public may wonder: How could that be? How could so many studies be wrong?

As this issue's cover story discusses, some research studies are more convincing than others-and quantity is no substitute for quality. A single large, well-designed clinical trial of a new drug can lead to approval by the FDA and get the medication onto doctors' prescription pads all over the country. But a hundred badly done studies, as our story explains, only add up to uncertainty and confusion.

After you read this article, we hope you will react with healthy skepticism whenever a brain-boosting dietary supplement is advertised to be "clinically proven" but not FDA-approved. Caution is always a consumer's best friend. Some supplements have indeed been subjected to rigorous testing, but the majority have not.

Before shelling out cash for a product that claims to affect memory - or any other aspect of your health - take some time to find out the facts. Look for products that have been tested in large-scale, long-term studies, preferably multiple studies conducted at several different sites. The more you know, the better chance you have of sorting the good from the bad.

Sincerely,

Catherine E. Myers, Ph.D.
Co-Director, Memory Disorders Project at Rutgers-Newark