There has also been speculation that DHEA might strengthen the immune response. While some studies in humans have backed up this theory, others have indicated that DHEA might help blunt immune responses-the opposite effect. In fact, some studies on women with autoimmune diseases (disorders in which the immune system mistakenly attacks tissues of the body-see Chapter 5) have used DHEA as an alternative to corticosteroids to suppress the immune system. Doctors sometimes prescribe corticosteroids to patients undergoing organ transplants in order to suppress the immune system. Thus, we just don't yet know for sure whether DHEA can strengthen immune responses, or to what degree. The studies that have shown significant benefits to the immune response were in studies conducted mostly on rodents, who do not produce DHEA naturally. Therefore, we can't assume this data applies to humans. So the fact is that when it comes to the effect of DHEA on the immune system, we don't yet know for sure exactly what it is.
More Answers from Michael Roizen, MD