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Pills,
Patches, and Shots
Can Hormones Prevent Aging?
Hormones are powerful
chemicals that help keep our bodies working normally. They are
made naturally, by the body, and can affect us in far-reaching
ways. Levels of some hormones decrease as a normal part of aging.
In other cases, the body may fail to make enough of a hormone
for other reasons. In either case, the body’s hormone levels
can be increased by taking hormone supplements — pills,
shots, or medicated skin patches.
Certain hormone supplements
have received a lot of attention lately, including DHEA (dehydro-epiandrosterone),
human growth hormone (hGH), melatonin, and testosterone. Unproven
claims that taking these supplements can make people feel young
again or that they can prevent aging have been appearing in
the news. However, when it comes to hormones, more is not necessarily
better.
The fact is that
no one has yet shown that supplements of these hormones add
years to people’s lives. And while some supplements provide
health benefits for people with genuine deficiencies of certain
hormones, they also can cause harmful side effects. The right
balance of hormones helps us stay healthy, but the wrong amount
might be dangerous.
Another concern is
that some hormone supplements are not regulated as drugs by
the Food and Drug Administration; they are sold as nutritional
supplements, instead. For this reason, the rules controlling
how they are produced and sold are not as strict as the rules
for drugs. For example, producers of DHEA and melatonin are
not required to include important health information on the
labels of their bottles. Researchers also have found that the
dose listed on the label of some bottles of melatonin may be
different from the dose inside the bottle.
The National Institute
on Aging (NIA), part of the National Institutes of Health, conducts
research to find out how hormone supplements affect people.
In the case of most hormone supplements, it is not yet known
how much is too much or too little, and for some, whether hormone
supplements should be taken at all. This fact sheet provides
information about what is known so far and about what researchers
are doing to find out more.
Talk
to Your Doctor
The NIA does not
recommend taking supplements of DHEA, growth hormone, or melatonin,
because not enough is known about them. People who have a genuine
deficiency of testosterone or human growth hormone (see below)
should take them only under a doctor’s supervision. The
NIA does not recommend taking any supplement as an anti-aging
remedy, because no supplement has been proven to serve this
purpose. Talk to your doctor to make sure that over-the-counter
supplements will not interfere with other medications you are
taking and that they will not affect any medical conditions
you may have. You might want to show this fact sheet to your
doctor, to help explain your concerns.
How
Hormones Work
Groups of special
cells — glands — make chemicals called hormones and
release them into the bloodstream. Hormones taken as supplements
also end up in the bloodstream. In either case, the blood then
carries hormones to different parts of the body. There, hormones
influence the way organs and tissues work.
Hormone supplements
may not have exactly the same effects on us that our own naturally
produced hormones have, because the body may process them differently.
Another difference is that high doses of supplements, whether
pills, skin patches, or shots, may result in higher amounts
of hormones in the blood than are healthy. When that happens,
any negative effects that even the body’s own hormones
can cause may increase. Tiny amounts of these powerful chemicals,
whether made by the body or taken as supplements, can have widespread
effects.
DHEA
DHEA is made by the
adrenal glands, which sit on top of each kidney. Although it
is not known whether DHEA itself causes hormonal effects, the
body breaks DHEA down into two hormones that are known to affect
us in many ways: estrogen and testosterone (see below). Supplements
of DHEA can be bought without a prescription, and also may be
found under the name "dehydroepiandrosterone." After
people reach the age of about 30, their bodies start to make
less DHEA, and the amount of DHEA found in the bloodstream continues
to drop as people grow older. Supplements are sold as an anti-aging
remedy claimed, by some, to improve energy, strength, and immunity.
DHEA is also said to increase muscle and decrease fat.
Right now, there
is no reliable evidence that DHEA supplements do any of these
things. However, there are early signs that DHEA supplements
may lead to liver damage, even when taken briefly.
Some people’s
bodies make large amounts of estrogen and testosterone from
DHEA, while others make smaller amounts. There is no way to
predict who will make more and who will make less. Researchers
are concerned that DHEA supplements may cause high levels of
estrogen or testosterone in some people. The body’s own
testosterone plays a role in prostate cancer, and high levels
of naturally produced estrogen are suspected of increasing breast
cancer risk. It is not yet known for certain if supplements
of estrogen and testosterone, or supplements of DHEA, also increase
the risk of developing these types of cancer. In women, high
testosterone levels increase the risk of heart disease and cause
growth of facial hair.
Overall, the studies
that have been done so far do not provide a clear picture of
the risks and benefits of DHEA. For example, some studies show
that DHEA helps build muscle, but other studies do not. Researchers
are working to find more definite answers about DHEA’s
effects on aging, muscles, and the immune system. In the meantime,
people who are thinking about taking supplements of this hormone
should understand that its effects are not fully known. Some
of these unknown effects might turn out to be harmful.
Growth
Hormone
Human growth hormone
(hGH) supplements also are claimed, by some, to reduce the signs
of aging — that is, to increase muscle and decrease fat,
and to give people a feeling of well-being and energy.
Even though there
is no proof that hGH can prevent aging, some people spend a
great deal of money on supplements. Shots of the hormone can
cost more than $15,000 a year. They are available only by prescription
and should be given by a doctor.
Human growth hormone
is made by the pituitary gland, just under the brain, and is
important for normal development and maintenance of our tissues
and organs. It is especially important for normal growth in
children. Human growth hormone levels often decrease as people
age.
Studies have shown
that supplements are helpful to certain people. Sometimes, children
are unusually short because their bodies do not make hGH. When
they take supplements, their growth improves. Young adults who
have no pituitary gland (because of surgery for a pituitary
tumor, for example) cannot make the hormone, and they become
obese. When they are given supplements, they lose weight.
Researchers are doing
studies to find out if hGH can help make older people stronger
by building up their muscles and whether it can reduce body
fat. They are watching their patients very carefully, because
side effects can be serious in older adults. Side effects of
hGH treatment can include diabetes and pooling of fluid in the
skin and other tissues, which may lead to high blood pressure
and heart failure. Joint pain and carpal tunnel syndrome also
may occur.
People in search
of the "fountain of youth" may have a hard time finding
a doctor who will give them shots of hGH. Some people put themselves
in danger by trying to get it any way they can. For example,
some people went to a clinic in Mexico to get supplements. The
clinic was shut down later because side effects were not being
carefully monitored by doctors.
Melatonin
The hormone melatonin
is made by the pineal gland, in the brain, and decreases with
age in some people.
Supplements of melatonin
can be bought without a prescription. Some people claim that
melatonin is an anti-aging remedy, a sleep remedy, and an antioxidant
(antioxidants protect against "free radicals," naturally
occurring molecules that cause damage to the body). Early test-tube
studies suggest that melatonin may be effective against free
radicals, in large doses. However, cells produce antioxidants
naturally, and in test-tube experiments, cells reduce the amount
they make when they are exposed to additional antioxidants.
Claims that melatonin
can slow or reverse aging are very far from proven. Studies
of melatonin have been much too limited to support these claims,
and have focused on animals, not people.
Research on sleep
shows that melatonin does play a role in the sleeping and waking
cycle people go through daily, and that supplements can improve
sleep in some cases. If melatonin is taken at the wrong time,
though, it can disrupt the sleep/wake cycle. The effects of
supplements differ from person to person, and more research
is needed to find out under what conditions melatonin helps,
not disturbs, sleep.
Side effects of melatonin
may include confusion, drowsiness, and headache the next morning.
Animal studies suggest that melatonin may cause blood vessels
to constrict, a condition that could be dangerous for people
with high blood pressure or other cardiovascular problems.
The dose of melatonin
usually sold in stores — 3 milligrams — can result
in amounts in the blood up to 40 times higher than normal. It
is important to remember that melatonin may be found to have
far-reaching effects that are still unknown even at the body’s
own normal levels, to say nothing of the levels that can be
caused by megadoses taken for long periods of time.
Researchers are working
to find out more about melatonin’s effects.
Testosterone
Testosterone is thought
of as a male hormone, but it is found in both men and women.
Because men have more testosterone, their voices are deeper,
they have more facial hair, and their muscles are larger. Testosterone
also plays a role in sex drive and erection.
Testosterone levels
may drop as men age, and changes that take place in older men
often are wrongly blamed on lower testosterone. For example,
the loss of erection some older men experience often is due
to unhealthy arteries, not low testos-terone levels.
Supplements of testosterone
are available, only by prescription, for men whose bodies do
not make enough of the hormone. Examples of men who do not make
enough testosterone are those whose pituitary glands have been
destroyed by infections or tumors, or whose testes have been
damaged (the testes are the glands that make testosterone in
men, and the pituitary gland helps regulate it).
Supplements provide
many benefits for men with a genuine deficiency of testosterone.
Men’s muscles and bones become smaller and weaker without
the hormone, and their sex drive and ability to have erections
decrease. Supplements help prevent such problems by restoring
normal levels.
But too much testosterone
is harmful. Stories about athletes who damaged their health
by taking steroids — testosterone supplements — to
build up muscle and strength have made headlines. Now, stories
about how testosterone can make older men feel young again,
and can restore their muscles and their sex drive, have become
popular.
The problem is that
most of these men already have enough testosterone, and supplements
cause them to have more than is normal. The result can be an
enlarged prostate gland; harmful cholesterol levels, which may
lead to heart disease; psychological problems; infertility;
and acne. It is not yet known for certain if testosterone supplements
increase the risk of prostate cancer.
Estrogen
Because many women
take estrogen supplements for symptoms of menopause, estrogen
is included in this fact sheet. Many large, reliable studies
have been done on this hormone, and show why it is important
to discover both the helpful and harmful effects of a supplement.
It is clear that estrogen replacement is helpful to some women
after menopause. Women with certain risk factors, however, might
decide, along with their doctors, that estrogen supplements
are not right for them.
Women have much less
estrogen after menopause because the ovaries make dramatically
reduced amounts of this reproductive hormone in later life.
Studies suggest that reduced estrogen levels are associated
with a higher risk of heart disease and osteoporosis —
a condition that weakens bones, allowing them to break more
easily. These are just two examples of the many areas of the
body that can suffer without adequate estrogen.
Research has shown
that estrogen supplements prescribed by a doctor can help some
women avoid osteoporosis and lower their risk factors for heart
disease, the number-one killer of women in the United States.
Osteoporosis can lead to severe bone fracture. Patients who
are hospitalized for a broken hip have a death rate 12 to 20
percent higher than others in their age group, due to complications.
Estrogen helps prevent osteoporosis.
A recent study suggests
that estrogen supplements also may delay the onset of Alzheimer’s
disease, but more research must be done to confirm this early
finding.
On the other hand,
some studies have raised concerns about a link between estrogen
and cancer of the uterus and a possible link between estrogen
and breast cancer. It appears that estrogen given to women after
menopause also increases the risk of blood clots. Heart attacks,
strokes, and other circulation problems may result from blood
clots.
Although much is
known about estrogen, scientists are learning more. For example,
a recent study suggests that older women whose bones are found
to be at lower risk of osteoporosis may be at higher risk of
breast cancer (doctors can predict a woman’s likelihood
of developing osteoporosis by measuring bone mineral density).
Researchers think this increased breast cancer risk may occur
in some women whose bodies have produced high amounts of natural
estrogen over their lifetime. More research is needed to tell
whether estrogen supplements alone increase the risk of breast
cancer.
Researchers have
studied estrogen for many years. As a result, doctors are better
informed about which women are likely to benefit from supplements
and about the right doses to prescribe so that the risk of side
effects is reduced. Adding progestin, another female hormone,
to estrogen supplements lowers risk of uterine cancer.
The decision whether
or not to take estrogen is a personal one. Each woman, along
with her doctor, should ask herself: Is there heart disease
in my family? Or breast cancer? What are the results of my bone
mineral density meas-urement? Have I had blood clots before,
or has my doctor told me that I am prone to blood clots?
There is no right
or wrong answer to these questions. Each woman must weigh her
answers, based on her health history, with her doctor.
Studies
Under Way
The NIA sponsors
many research projects that will reveal more about the risks
and benefits of hormone supplements. One goal is to dis-cover
how DHEA, melatonin, and other supplements affect people over
time.
Trophic factors are
substances that help control the growth and repair of our tissues
and organs throughout our lives. Some trophic factors are considered
hormones. Researchers are studying them to find out if decreasing
levels of these factors are responsible, at least in part, for
the diseases and disabilities seen in aging. Now in its fourth
year, a group of 5-year studies of trophic factors is under
way. Testosterone, estrogen, and growth hormone are included
in the study.
It is important to
remember that these studies may not give immediate or final
answers, especially in the case of DHEA, melatonin, and human
growth hormone, since research on these supplements is fairly
new. For example, some of the studies may simply give researchers
more information about what kinds of questions they should ask
in their next studies. Research is a step-by-step process, and
larger studies may be needed to give more definite answers.
Until more is known
about DHEA, melatonin, and hGH, consumers should view them with
a good deal of caution — and doubt. Despite what advertisements
or stories in the media may claim, hormone supplements have
not been proven to prevent aging. Some harmful side effects
already have been discovered, and further research may uncover
others.
More is known about
estrogen and testosterone, and people who are concerned about
genuine deficiencies of these hormones should consult with their
doctors about supplements. Meanwhile, people who choose to take
any hormone supplement without a doctor’s supervision do
so at their own risk.
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