DHEA is a natural circulating hormone and the body's production of it decreases with age. Men take DHEA as an over-the-counter supplement because it has been suggested that DHEA can reverse aging or have anabolic effects since it can be metabolized in the body to androgens.

Experts estimate there are at least 30 million people who are living with dementia worldwide. By the year 2050, they say there will be as many as 100 million facing the disease. VOA's Melinda Smith has details of the latest study on an ancient herbal supplement Ginkgo Biloba, which has shown some promise in previous studies, but unsuccessful in Alzheimer's disease treatment.

Recently, scientists demonstrated the anti-cancer effects of silibinin, a major biologically active compound of milk thistle. Being widely used as a folk remedy for liver diseases, milk thistle is safe and well-tolerated, and it protects the liver from drug or alcohol-related injury.

Milk thistle extract, an herbal remedy since the times of the ancient Greeks and Romans, is today one of the most popular herbal supplements, with U.S. retail sales of nearly nine million dollars.

North Central Cancer Treatment Group (http://ncctg/) (NCCTG) researchers, based at Mayo Clinic in Rochester, Minn., have generated preliminary data suggesting that a form of American ginseng provides greater improvements in fatigue and vitality in patients who receive the highest doses tested, compared to lower doses or no treatment.

Recent findings that the widely-used herbal supplement Saint John's wort could dramatically affect the absorption and metabolism of many prescription and non-prescription drugs raised concerns that other popular herbal supplements might cause similar changes, thus significantly altering drugs' therapeutic or toxic effects.

A new study from the University of Pittsburgh Cancer Institute suggests that a commonly used herbal supplement, triphala, has cancer-fighting properties that prevent or slow the growth of pancreatic cancer tumors implanted in mice. The study found that an extract of triphala, the dried and powdered fruits of three plants, caused pancreatic cancer cells to die through a process called apoptosis - the body's normal method of disposing of damaged, unwanted or unneeded cells.