The new work, conducted by a team of scientists at the University of Wisconsin-Madison, provides some of the first direct evidence of the biological effects of DHEA on the human nervous system, according to Clive Svendsen, the study's senior author and an authority on brain stem cells at UW-Madison's Waisman Center.
"What we saw was that DHEA significantly increased the division of the cells," says Svendsen, a UW-Madison professor of anatomy and neurology. "It also increased the number of neurons produced by the stem cells, prompting increased neurogenesis of cells in culture."
DHEA or dehydroepiandrosterone is among the most abundant naturally occurring steroids in the blood of young humans, but levels decline with age and its physiological effects are poorly understood. A synthetic form of the hormone is sold over-the-counter. Its supposed benefits range from antiaging properties to the prevention of cancer and heart disease, and serving as a supplement to counter the effects of strokes, AIDS, Alzheimer's and other diseases.
But while DHEA is readily available in health-food stores and other venues, scientists know relatively little about the drug and its basic biological effects on humans. Many experts familiar with DHEA caution against its overuse.
"We don't know much about DHEA, but this new work adds a piece to the puzzle," says Svendsen, who conducted the study with colleagues Masatoshi Suzuki, Lynda S. Wright, Padma Marwah and Henry A. Lardy, all of UW-Madison. "This is the first real evidence of DHEA's effects on human neural cells."