Study: Supplement DHEA Appears to Have No Benefit for Alzheimer's

The supplement dehydroepiandrosterone (DHEA) produced no beneficial effect on Alzheimer's patients who used it for six months, according to a study published in the April 8 issue of Neurology.

DHEA is a hormone produced naturally in the adrenal glands. The body then converts it into the hormones estrogen and testosterone. DHEA as a supplement is made from plant chemicals.

Previous research has found that DHEA levels peak in people between the ages of 20 and 30 and then decrease progressively with age. Other studies have found that DHEA improves memory in mice. Studies on the levels of DHEA in the blood of Alzheimer's patients have been conflicting.

Researchers gave 58 Alzheimer's patients either 100 mg per day of DHEA or a placebo. The patients were tested for cognitive functioning and rated by physicians and caregivers on any changes in the severity of the disease.

DHEA did not significantly improve cognitive performance or ratings of disease severity at the end of six months. Study author Dr. Owen Wolkowitz, of the University of California at San Francisco, said cognitive performance may have improved at the end of three months of treatment, but it narrowly missed statistical significance.

In an accompanying editorial to the study, Dr. David Knopman, a neurologist at the Mayo Clinic in Rochester, Minn., said the small size of the study and the high number of people who dropped out may limit the findings of the study.

Of the 58 people who started the study, 46 completed three months of treatment and 33 completed six months of treatment. Knopman said larger studies are needed to test these findings.

The study was limited to people who were not taking drugs commonly used for Alzheimer's. Wolkowitz said the high number of dropouts might be due to participants deciding to switch to Alzheimer's drugs in mid-stream of the study. In the future, he said DHEA should be tested in combination with these drugs to see whether they are enhanced.

Wolkowitz said no studies have been done on the long-term effects of taking DHEA supplements. "Because it metabolizes into testosterone and estrogen, it has the theoretical potential to stimulate the growth of hormone-sensitive cancers, such as breast or prostate cancers," he said. "The actual risk of this is an area of much debate among researchers."

Other sources: American Academy of Neurology