Dehydroepiandrosterone (pronounced dee–hi–dro–epp–ee–ann–dro–stehr–own), or DHEA as it is more often called, is a steroid hormone produced in the adrenal gland. It is the most abundant steroid in the bloodstream and is present at even higher levels in brain tissue. Dehydroepiandrosterone levels are known to fall precipitously with age, falling 90% from age 20 to age 90. DHEA is known to be a precursor to the numerous steroid sex hormones (including estrogen and testosterone) which serve well–known functions, but the specific biological role of Dehydroepiandrosterone itself is not so well understood.
It is difficult for researchers to separate the effects of DHEA from those of the primary sex steroids into which it is metabolized. The apparent lack of any direct hormone action for DHEA has prompted the suggestion that it may serve the role of a “Buffering hormone” which would alter the state–dependency of other steroid hormones. Although the specific mechanisms of action for DHEA are only partially understood, supplemental DHEA has been shown to have anti–aging, anti–obesity and anti–cancer influences. In addition, it is known to stabilize nerve–cell growth and is being tested in Alzheimer’s patients.
Our understanding of the specific mechanisms of DHEA in metabolism has recently been advanced by the publication of The Biologic Role of Dehydroepiandrosterone (DHEA), edited by Mohammed Kalimi and William Regelson . This book presents 24 chapters from scientists around the world who are conducting DHEA research. The breadth of the work is impressive. As Dr. Regelson, Kalimi and Loria stated in their introductory remarks, “DHEA modulates diabetes, obesity, carcinogenesis, tumor growth, virus and bacterial infection, stress, pregnancy, hypertension, collagen and skin integrity, fatigue, depression, memory and immune responses”. With this wide range of potential clinical uses, it is amazing that more books about Dehydroepiandrosterone have not been written.
The introductory chapter, by the editors and Roger Loria, briefly reviews DHEA’s biochemistry, endocrinology, and potential clinical uses. They contend that it is perhaps the most significant endocrine biomarker known, and further postulate that all of its effects may be explained by its action as a precursor hormone which provides “A host of steroid progeny with which to maintain the broad balance of host response related to species and individual survival”.
DHEA and Cancer
Early reports from England [Bulbrook, 1962, 1971] suggested that DHEA was abnormally low in women who developed breast cancer, even as much as nine years prior to the onset or diagnosis of the disease. Of the 5000 women followed in the study, 27 developed cancer. Most of the 27 had abnormally low levels of DHEA. If low DHEA levels contributed to breast cancer, might the opposite be true? Many years later, Dr. Arthur Schwartz of Temple University found that supplemental DHEA significantly protected cell cultures from the toxicity of carcinogens. Cell cultures usually respond to powerful carcinogens with mutations (changes in DNA), transformations (changes in cell appearance), and a high rate of cell death. But when Schwartz added Dehydroepiandrosterone along with the carcinogen, all three of these effects were significantly diminished.
Subsequent studies [Schwartz, 1979] identified powerful protective effects of supplemented DHEA for breast–cancer–prone mice. The results of the experiment was clear after 8 months. The control animals were “Getting cancer left and right” while the DHEA animals had no tumors. Although DHEA is now beginning to be tested in human cancer, it is still too early to know whether the successes achieved in animals will be realized in humans.
The Anti–Obesity Factor
At about the same time that Schwartz was investigating the anti–cancer properties of DHEA, Dr. Terrence T. Yen was studying the effect of DHEA on genetically obese mice. Although the DHEA–treated mice ate normally, they remained thin – and they lived longer than control mice. This “Leanness” effect was also conspicuously noted by Dr. Schwartz. In another experiment, Dr. M. P. Cleary found that even middle–aged obese rats lost weight when fed DHEA–supplemented food. Diabetes, a typical complication of obesity, was also dramatically decreased.