Health food stores have been selling cytosterol, a precursor of DHEA derived from yams that has not been proven to benefit humans. Studies of DHEA supplementation in aging animals are the basis for its health claims. DHEA is a potent pre-hormone that definitely creates estrogen and testosterone. It has been approved to treat jet lag. As with DHEA, it has not been proven either safe or effective in humans, though animals studies are promising.
Preliminary data suggest some cardiovascular benefit.
More than ever, people are looking to non-hormonal means to stave off the frailties of aging. Many investigators are assessing the ability of soy isoflavones in preventing heart disease, breast cancer and bone loss. Results are promising but preliminary. Researchers suggest taking 30-50 mg of isoflavones per day. Studies are numerous and ongoing but data is unclear at present.