Interest in strategies to delay the ravages of age continue to escalate. Many people, feeling the pressure of time, prefer not to wait for proof of efficacy and fall prey to fringe practitioners and entrepreneurs peddling such nostrums as melatonin, growth hormone (GH), and dihydroepiandosterone (DHEA).
DHEA is the most recent hormone to have achieved notoriety as a panacea for aging. One only has to scan the Internet to see that it is in wide use in the general population. Walk the aisles of your local supermarket or supplement store and capsules of this potent oral steroid can be found for sale with various protein powders and vitamins.
DHEA and its alternative form DHEA-S are weak androgenic (masculinizing) steroid hormones which are normally produced by the adrenal gland. The mechanism of action of DHEA is poorly understood. In the body, DHEA can also be converted to the more potent androgens: androstenedione, testosterone (T), and dihydrotestosterone (DHT). Thus with large oral doses of DHEA, the serum levels of DHEA, DHEA-S, T, and DHT all quickly rise to abnormal levels. Even mild elevation of these hormones as is seen in polycystic ovary syndrome has been associated with adverse health effects including male-pattern hair growth and balding, insulin resistance leading to diabetes, and increase in heart disease secondary to effects on cholesterol.
Why replace DHEA in aging women? It has been shown that serum levels of this hormone fall with advancing age. In children DHEA levels are low until 8-10 years of age, but the increase to peak levels by the age of 25. Subsequently, DHEA levels decline to negligible levels by age 70. DHEA replacement when taken in appropriate doses may have beneficial effects, in much the same way as does estrogen replacement.
Much of the excitement about the potential of DHEA replacement is based on animal studies. In rats and mice, high dose DHEA has been shown to prevent obesity and noninsulin-dependent diabetes, enhance immune system functioning, protect against cancer development, and improve performance of cognitive tasks. These findings are tantalizing when one considers that obesity, noninsulin-dependent diabetes, increases in cancer development, cognitive declines and immune impairment are all age-related phenomena in humans. Unfortunately the data regarding the effects of DHEA administration to humans is scarce. Studies that have been done show an enhancement of the immune system and an insulin sensitizing effect which should be protective against diabetes. Additionally there appears to be a potentiation of growth factors in the blood. Given recent information linking growth hormone administration, attenuation of aging, and improved cardiac function, this may be of considerable clinical relevance.
Other recent clinical data have demonstrated more possible benefits including increased rapid eye movement (REM) sleep which may lead to better cognitive functioning during wakeful hours, improved immune response of the elderly to vaccination, antiviral activity against HIV, and reduced severity of symptoms in patients with Systemic Lupus Erythematosis (SLE). It is important to note that all of these studies are short term; the longest reported being 6 months.
One also has to wonder about the number of negative studies regarding DHEA that have not been published. Efficacy is not yet clearly established. DHEA supplementation may have important side effects. DHEA has been shown to cause abnormalities of liver function with one patient developing jaundice two weeks after a single oral dose of 150mg. This is particularly alarming since DHEA in high doses is known to induce liver cancer in laboratory rats. Additionally, biotransformation of DHEA to Testosterone may lead to an increased low density lipoproteins (LDL) and increased cardiovascular risk.
Initial findings in humans regarding use of low doses of DHEA as an anti-aging hormone replacement therapy are promising. The most reproducible effect is that of immune augmentation, but there also appears to be an insulin sensitizing effect and augmentation of the growth hormone axis.
All these findings give promise to the eventual use of DHEA as an adjunct to estrogen replacement therapy. However, at present, long-term efficacy and safety data do not exist. The mechanism of DHEA effect is unknown. Potential adverse liver and lipoprotein effects of oral DHEA remain problematic. For these reasons we do not advocate the clinical use of DHEA.
from: "DHEA replacement after menopause: HRT 2000 or nostrum of the 90s?"
by Peter R. Casson, MD, and John E Buster, MD,
CONTEMPORARY OB/GYN, April 1997.