Life Extension Magazine August 2001
DHEA: Anti-Aging Hormone
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REDUCES INFLAMMATION, ENHANCES IMMUNITY, PROTECTS ARTERIES AND THE BRAIN - by Ivy Greenwell
Dehydroepiandrosterone (DHEA) hormones are the most abundant circulating steroids in the human body. Low levels of DHEA are associated with aging and disease states. Specifically, a deficiency of DHEA has been found to correlate with immune dysfunction, inflammation, greater risk of certain cancers, heart disease in men, and osteoporosis. The special interest in DHEA replacement, however, stems from its function as a prohormone, meaning a precursor to a great variety of beneficial steroids, both in the estrogenic and androgenic family, on an “as-needed” basis.
Perhaps the most exciting new finding relates to the antiatherogenic benefits of DHEA. The dramatic aging-related drop in DHEA levels is accompanied by an equally dramatic rise in cardiovascular disease. We have now come closer to elucidating the cardioprotective mechanism of DHEA. It appears that DHEA is incorporated into both high and low-density cholesterol, protecting it from oxidation. In the aged, however, cholesterol-bound DHEA becomes virtually undetectable, and the cholesterol molecules are much more susceptible to oxidation than in young individuals. But this is not the end of the story. It turns out that DHEA also increases the activity of platelet superoxide dismutase (SOD), one of our most important antioxidant enzymes. Thus, DHEA seems to play an essential role as part of the body’s antioxidant defenses.
Another recent finding involves the anti-inflammatory properties of DHEA. It has been known for a long time that DHEA can lower the levels of interleukin-6 (IL-6), a pro-inflammatory cytokine (meaning a chemical messenger used by the immune system) that seriously escalates the inflammatory process, recruiting immune cells that often end up destroying healthy tissue as well. Now it has been established that DHEA can lower the production of another inflammatory cytokine as well, one called tumor necrosis factor alpha (TNF-alpha). The levels of both IL-6 and TNF-alpha rise with aging, showing an increased inflammatory state and possible immune dysfunction. The role of DHEA in regulating the immune response has been shown to include also the enhanced secretion of interferon-gamma. The decline in DHEA levels is closely tied to immunosenescence.
This is excellent news for those who suffer from chronic inflammatory diseases. However, it could be argued that aging itself is, in a sense, a chronic inflammatory state. The levels of various chemical mediators of inflammation, such as IL-6 and TNF, increase as we age. At the same time, our production of DHEA plummets with aging. Maintaining youthful levels of DHEA means less chronic inflammation. It should be pointed out that chronic inflammation is known to play a critical role in the development of the killer diseases of aging: heart disease, Alzheimer’s disease and certain types of cancer.
More good news includes also the finding that DHEA protects brain tissue under conditions simulating stroke and trauma damage, and is likely to be involved in protecting the brain against the development of Alzheimer’s disease. The neuroprotective mechanism of DHEA appears to go beyond its anti-glucocorticoid effect, that is, its ability to antagonize the harmful effects of cortisol; anti-inflammatory action is likely to be involved as well. DHEA has also been shown to lower hyperglycemia (elevated blood sugar) in diabetic rats, and protect their kidneys from the damage caused by high blood sugar. In addition, DHEA enhances the immune response and helps us fight infection; several studies have confirmed its usefulness in combating bacterial, parasitic and viral infections, including HIV. DHEA also helps protect the thymus against cortisol-induced atrophy.