Hormones' Anti-Aging Potential Draws Attention
June 23, 2000 -- Since the days of Juan Ponce de Leon, mankind has been in a never-ending search for the Fountain of Youth. While there is still no magic tonic to reverse the aging process, a growing body of research suggests that substances called trophic factors, such as the human growth hormone and the sex hormones estrogen and testosterone, may be key ingredients.
That's good news, because the search has never been more urgent. Approximately 7 million elderly Americans now need long-term care to manage many activities of daily living, and the number will double by 2030 unless disability rates among older people decline, according to the U.S. Bipartisan Commission on Comprehensive Health Care.
Preliminary studies suggest that supplements of human growth hormone (GH), in particular, may reduce frailty, improve function, and maintain independence in older people.
Growth hormone is a protein produced by the pituitary gland. It triggers the release of an insulin-like growth factor that develops and maintains various tissues and organs.
Levels of testosterone in men and estrogen in women are known to decline with age, and some studies have shown that levels of GH also drop with age. There is some evidence -- but no proof -- that replacing both growth hormone and sex hormones in the body could help stave off some of the illnesses associated with advancing age.
Prompted by reports that extra GH increased lean body mass while decreasing body fat and the effects of aging among healthy men 65 and up who had low levels of GH, the National Institutes on Aging (NIA) in Bethesda, Md., awarded grants to eight researchers to study the hormone in 1992.
The studies are ongoing, and, to date, their results have been mixed. One study showed a 13% reduction in body fat among men taking GH, a 5.8% reduction among men taking only testosterone, and a 21% reduction in men taking both GH and testosterone. Other studies showed that people who took supplements of GH reduced their levels of low-density lipoprotein, or "bad" cholesterol.
Another study, however, showed that participants' triglycerides, or blood-fat levels, increased when they took GH. High levels of triglycerides are a risk factor for heart disease. Another consideration is that taking growth hormone and other hormones may cause sometimes-serious side effects, including carpal tunnel syndrome, worsening of diabetes, and fluid retention leading to congestive heart failure.