Two hormones available over the counter, melatonin and
Dehydroepiandrosterone (DHEA), have become the focus of the
escalating–and increasingly controversial–search for the secret
of eternal youth. Research on both hormones has shown considerable
promise in the prevention and perhaps even reversal of such
age-related diseases as cancer, heart disease, diabetes, arthritis,
osteoporosis, and even Alzheimer’s disease. Users of both
substances have also reported improved sleep, memory, mood, and
energy levels. ‘By restoring levels of the two hormones to their
youthful peaks, people may be able to add up to 30 healthy years to
their lives,’ reports Burkhard Bilger in The Sciences
(Sept./Oct. 1995).
Melatonin is a natural sleep-inducer synthesized by the brain’s
pineal gland. DHEA, one of many hormones produced by the adrenal
glands, turns into either estrogen or testosterone–whichever the
body needs at the moment–and also has properties independent of
either of these sex hormones. As we grow old, we manufacture fewer
and fewer of these vital hormones, and some evidence suggests that
this slowdown may speed the aging process. There’s also some
evidence that the converse may be true.
According to a 1993 study conducted by Italian scientist Walter
Pierpaoli, old mice receiving either hormone soon looked and acted
about half their age and greatly surpassed their life expectancies.
Amid the media hoopla that followed this discovery, an important
footnote was overlooked: The anti-aging effects kicked in only
after the mice were a year and a half old, the equivalent of about
45 to 50 human years. If you’re young and wish to slow down the
aging clock, you may want to wait a few decades before you start
taking melatonin. Timing may be of the essence for DHEA as well.
Most researchers advise against taking it before age 50.
Those aren’t the only caveats. Some scientists claim that
raising the melatonin level could trigger a drop in the pineal
gland’s production, or reduce the number of ‘melatonin receptors’
on body cells. Either way, the body’s ability to produce or use
melatonin could become limited over time. This phenomenon, termed
‘down regulation,’ was first observed in melatonin-injected lab
animals in the 1960s by researcher Russel Reiter, co-author of
Melatonin (Bantam, 1995), who is troubled by the recent
melatonin craze. ‘Frankly, the idea that so many people are now
taking melatonin is a bit unsettling to the scientific community,’
he told Natural Health (March/April 1996).
Similar concerns have been aired regarding long-term use of
DHEA. It is among the most ubiquitous hormones, and DHEA receptors
are found on many types of body cells. ‘I was astounded that there
were physicians out there giving this drug to thousands of people
in the absence of any studies about what it does,’ Dr. Elizabeth
Barrett-Connor told The Sciences. Her own research found
that high blood DHEA-sulfate levels reduced the risk of heart
disease in men, but seemed to increase it in women. Other side
effects may include masculine hair growth, acne, and a receding
hairline in women. Postmenopausal women with low estrogen levels
who take DHEA appear to be at an increased risk of breast cancer,
according to The Lancet (May 13, 1996). (In contrast,
younger women who take DHEA actually appear to be protected against
breast cancer.) A substantial number of lab animals on DHEA have
developed liver cancer, though it’s still not clear what these
findings mean for humans.
The scientific community is also concerned about the risk of
contamination as the use of melatonin and DHEA becomes more
widespread. ‘There’s always the chance that we could get a bad
batch of melatonin,’ says Dr. Dan Oren of the National Institutes
of Health. ‘And just as happened with the contaminated L-tryptophan
batch a few years ago, that could be disastrous. There may need to
be more scrutiny and assured quality control on the manufacturing
end.’
Such concerns have fueled the lobbying efforts of some
pharmaceutical companies, which would like to see melatonin
regulated as a drug, to be made available by prescription only.
DHEA is already under close Food and Drug Administration scrutiny.
The agency has not approved the hormone, and few doctors will
prescribe it, but a loophole created by the Dietary Supplement
Health and Education Act of 1994 allows DHEA synthesized from
cytosterol found in Mexican yams to be sold over the counter in
health food stores and through mail-order firms.
Still, because the pharmaceutical industry is reluctant to spend
the millions required to study unpatentable substances like
melatonin and DHEA, the true benefits and risks of these hormones
are likely to be judged only by anecdotal evidence in humans.
Indeed, the sudden surge of interest in anti-aging hormones marks
the beginning of a vast, uncontrolled experiment whose results will
remain unknown for decades.
Meanwhile, there are commonsense ways to beef up the body’s own
supply of these hormones: Avoid high-protein diets, alcohol, drugs,
tobacco, caffeine, sleep deprivation, and overeating.
Unfortunately, as people become more and more enamored of these
hormones, they may be less inclined to pay attention to the basics
of healthful living–making that quick fix all the more
alluring.
