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DHEA Not just For Bodybuilders
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Dehydroepiandrosterone (pronounced dee-hi-dro-epp-ee-ann-dro-stehr-own),
or DHEA as it is more often called, is a steroid hormone produced in the
adrenal gland. It is the most abundant steroid in the bloodstream and is
present at even higher levels in brain tissue. DHEA levels are known to
fall precipitously with age, falling 90% from age 20 to age 90. DHEA is
known to be a precursor to the numerous steroid sex hormones (including
estrogen and testosterone) which serve well-known refunctions, but the
specific biological role of DHEA itself is not so well understood. It is
difficult for searchers to separate the effects of DHEA from those of the
primary sex steroids into which it is metabolized. The apparent lack of
any direct hormone action for DHEA has prompted the suggestion that it may
serve the role of a “buffering hormone” which would alter the
state-dependency of other steroid hormones. Although the specific
mechanisms of action for DHEA are only partially understood, supplemental
DHEA has been shown to have anti-aging, anti-obesity and anti-cancer
influences. In addition, it is known to stabilize nerve-cell growth and is
being tested in Alzheimer’s patients.
Our understanding of the specific mechanisms of DHEA in metabolism has
recently been advanced by the publication of The Biologic Role of
Dehydroepiandrosterone (DHEA), edited by Mohammed Kalimi and William
Regelson [1990]. This book presents 24 chapters from scientists around the
world who are conducting DHEA research. The breadth of the work is
impressive. As Drs. Regelson, Kalimi and Loria stated in their
introductory remarks, “DHEA modulates diabetes, obesity, carcinogenesis,
tumor growth, neurite outgrowth, virus and bacterial infection, stress,
pregnancy, hypertension, collagen and skin integrity, fatigue, depression,
memory and immune responses.” With this wide range of potential clinical
uses, it is amazing that more books about DHEA have not been written.
The introductory chapter, by the editors and Roger Loria, briefly
reviews DHEA’s biochemistry, endocrinology, and potential clinical uses.
They contend that it is perhaps the most significant endocrine biomarker
known, and further postulate that all of its effects may be explained by
its action as a precursor hormone which provides “a host of steroid
progeny with which to maintain the broad balance of host response related
to species and individual survival.”
DHEA and Cancer
Early reports from England [Bulbrook, 1962, 1971] suggested that DHEA
was abnormally low in women who developed breast cancer, even as much as
nine years prior to the onset or diagnosis of the disease. Of the 5000
women followed in the study, 27 developed cancer. Most of the 27 had
abnormally low levels of DHEA. If low DHEA levels contributed to breast
cancer, might the opposite be true? Many years later, Dr. Arthur Schwartz
of Temple University found that supplemental DHEA significantly protected
cell cultures from the toxicity of carcinogens. Cell cultures usually
respond to powerful carcinogens with mutations (changes in DNA),
transformations (changes in cell appearance), and a high rate of cell
death. But when Schwartz added DHEA along with the carcinogen, all three
of these effects were significantly diminished.
Subsequent studies [Schwartz, 1979] identified powerful protective
effects of supplemented DHEA for breast-cancer-prone mice. The results of
the experiment was clear after 8 months. The control animals were
“getting cancer left and right” while the DHEA animals had no tumors.
In two later studies with different strains of mice, Schwartz found 75%
and 100% reductions in tumor incidence at 8 months of age and 50% and 75%
reductions at 15 months of age [Schwartz, 1981; 1984]. DHEA has
demonstrated protective effects for cancers of the skin, lungs, bowel,
breast and liver. According to William Regelson, “Whenever [DHEA] has
been tested in a model of carcinogenesis and tumor induction, DHEA has
preventative effects.” Although DHEA is now beginning to be tested in
human cancer, it is still to early to know whether the successes achieved
in animals will be realized in humans.
The Anti-Obesity Factor
At about the same time that Schwartz was investigating the anti-cancer
properties of DHEA, Dr. Terrence T. Yen was studying the effect of DHEA on
genetically obese mice. Although the DHEA-treated mice ate normally, they
remained thin — and they lived longer than control mice. This
“leanness” effect was also conspicuously noted by Dr. Schwartz. In
another experiment, Dr. M. P. Cleary found that even middle-aged obese
rats lost weight when fed DHEA-supplemented food. Diabetes, a typical
complication of obesity, was also dramatically decreased.
DHEA and Glucose Metabolism
Investigators have shown that DHEA inhibits glucose-6-phosphate
dehydrogenase (G6PDH), an enzyme that breaks down glucose. There are two
glucose-metabolizing pathways in the body, the catabolic, energy-yielding
pathway and the anabolic, biosynthetic pathway. G6PDH happens to be the
first enzyme in the biosynthetic pathway, the one which results in the
synthesis of fatty acids and ribose (the sugar used in making
deoxyribonucleic acid, or DNA). In simple language, G6PDH turns glucose
into fat.
DHEA’s inhibition of G6PDH may redirect glucose from anabolic
fat-production into catabolic energy metabolism, thus creating a leaner
metabolism. This function of DHEA is well reviewed by Arthur Schwartz and
colleagues in their chapter on “The Biological Significance of
Dehydroepiandrosterone” in The Biologic Role of
Dehydroepiandrosterone. They assert that DHEA-mediated reductions in
ribose-5-phosphate activity may be centrally responsible for the
anti-tumor promoting, anti-tumor initiating, and possibly the anti-atherogenic
properties of DHEA. They also note that DHEA 1) produces hepatomegaly
(liver enlargement), 2) stimulates liver catalase activity (a protective
antioxidant enzyme), and 3) causes proliferation of peroxisomes (cellular
organelles which specialize in oxidative processing and the decomposition
of hydrogen peroxide). The absence of such influences with synthetic
analogs of DHEA (like 16-alpha-fluoro-5-androsten-17-one) prompts Schwartz
and colleagues to recommend that such analogs be considered for clinical
applications in humans. Toxicity factors still need to be assessed.
DHEA and Appetite
In different experiments, DHEA supplementation has resulted in
increased, decreased and unchanged food consumption. Dr. Schwartz found
that it is the level of dietary fat influences food consumption. DHEA-treated
rats on a high-fat diet ate less food than control rats while those on a
low-fat diet ate more.
Since DHEA inhibits G6PDH activity and suppresses the body’s ability
to synthesize fat from carbohydrate, dietary sources of fat become more
important. This can affect changes in appetite. But despite possible
increases in food intake, DHEA-treated animals consistently weighed less
than control animals. In other words, increases in appetite, when
indulged, did not negate the anti-obesity property of DHEA.
DHEA and Aging
The body’s production of DHEA drops from about 30 mg at age 20 to
less than 6 mg per day at age 80. According to Dr. William Regelson of the
Medical College of Virginia, DHEA is “one of the best biochemical
bio-markers for chronologic age.” In some people, DHEA levels decline
95% during their lifetime — the largest decline of an important
biochemical yet documented.
In animal studies, DHEA extends rodent lifespans up to 50%. The animals
not only lived longer, they looked younger. The graying, course-haired
controls could easily be distinguished from the sleek, black-haired, DHEA-treated
animals.
DHEA levels are directly related to mortality (the probability of
dying) in humans. In a 12-year study of over 240 men aged 50 to 79 years,
researchers found that DHEA levels were inversely correlated with
mortality, both from heart disease and from all causes. This finding
suggests that DHEA level measurements can become a standard diagnostic
predictor of disease, mortality and lifespan. Furthermore, if animal
results hold true, supplemental DHEA may prevent disease, reduce
mortality, and extend lifespan in humans.
Enhancing Brain Function
DHEA may also be intimately involved in protecting brain neurons from
senility-associated degenerative conditions, like Alzheimer’s disease.
Not only do neuronal degenerative conditions occur most frequently when
DHEA levels are lowest, but brain tissue contains many times more DHEA
than is found in the bloodstream. One of the scientists at the forefront
of this field of research is Dr. Eugene Roberts who found that very low
concentrations of DHEA were found to “increase the number of neurons,
their ability to establish contacts, and their differentiation” in cell
cultures. He also found that DHEA also enhanced long-term memory in mice
undergoing avoidance training. It may play a similar role in human brain
function.
Drs. Roberts and Fitten report initial research on “Serum steroid
levels in two old men with Alzheimer’s disease before, during and after
oral administration of DHEA” in the book The Biologic Role of
Dehydroepiandrosterone. Roberts’ and Fitten’s data are the best
we’ve seen regarding acute and chronic changes in numerous hormone
levels following various oral doses of DHEA (see adjacent graphs). Because
of the short peak duration of DHEA (heavier line in illustration), they
recommend that future studies or therapeutic trials use time-release
capsules or transdermal patches to provide more uniform delivery of DHEA.
Levels of pregnenolone and 17-alpha-pregnenolone, the direct precursors
to DHEA, were too low to be measured in the two patients illustrated, but
Roberts and Fitten present data from three other Alzheimer’s patients.
Their data indicate that in all three patients, “control values for
pregnenolone and 17-alpha-pregnenolone not only were below the means for
the population controls, they were lower than the lowest values.” In
other words, the highest of the Alzheimer’s patients was lower than the
lowest of the population controls. When they were administered 400 mg of
DHEA, all three experienced decreased levels of 17-alpha-pregnenolone.
Pregnenolone levels increased in two patients and fell in the third. In
the two patients experiencing increased pregnenolone and decreased
17-alpha-pregnenolone in response to DHEA, levels of 17-alpha-pregnenolone
rebounded strongly at 24 hours. Roberts and Fitten suggest that “a
prolonged inhibition of 17-alpha hydroxylation occurred as a result of
continued DHEA intake.”
DHEA and Immune Function
DHEA
is known to enhance general immune response. Oral and subcutaneous
DHEA has been observed to protect rodents against the lethality of RNA and
DNA viruses, and lethal bacterial infections. Drs. Loria, Regelson and
Padgett report in The Biologic Role of Dehydroepiandrosterone (DHEA)
that a single subcutaneous dose of DHEA is considerably more
effective in protecting against infection than oral dosing.
Intraperitoneal [within the abdominal cavity] injections were completely
ineffective.
Dr. Loria and colleagues noted that subcutaneous dosing did not result
in the typical weight loss observed with oral DHEA. Presumably it works by
a different mechanism. DHEA has been reported to counteract the thymic
involution [shrinking of the thymus gland] and immuno-suppression caused
by corticosteroids. But the special role of skin tissues in the immune
facilitating properties of DHEA suggest a different mechanism is involved.
Cutaneous immune cells, such as Langerhans cells and keratinocytes, are
believed to play a role in “immune surveillance” and “antigen
presentation.” These cells may be a site of DHEA’s action.
Subcutaneous injection of DHEA results in the “formation of a local
deposit leading to a relatively prolonged exposure to the lymphoid
system.” DHEA skin patches might provide a similar exposure.
The delay in protective effect of subcutaneous DHEA has prompted Loria
and colleagues to postulate that a DHEA metabolite is involved in
cutaneous immune enhancement. In a recent paper [Loria and Padgett, 1993],
they advance androstenediol [5-androsten-3-beta-17-beta-diol] as the
active metabolite, the production of which is predominantly localized in
the skin and brain. They found that androstenediol was significantly more
effective than DHEA (10,000 times more with coxsackievirus B4!).
Neither DHEA nor androstenediol have any direct (in vitro)
antiviral activity. The amount of viral load in heart, spleen, pancreas,
liver and blood tissues was unaffected by either DHEA or androstenediol
administration. The effect of these steroids appears to be strictly
mediated through stimulation of lymphocytes, lymphoid organs, and
immune-modulating cytokines [immune hormones].
DHEA: The Buffering Steroid?
DHEA may be unique among hormones for it’s lack of specificity
forhormone receptor sites. Just as vitamin E has never been shown to have
a specific metabolic role (it is only proven essential as a general
antioxidant), DHEA may serve an equally general purpose. “DHEA is the
first example of a buffer action for hormones that I know of,” states
William Regelson. “It is a broad-acting hormone that only demonstrates
itself under a specific set of circumstances. In that way, it is like a
buffer against sudden changes in acidity or alkalinity. That is why when
you get older, you’re much more vulnerable to the effects of stress. As
DHEA declines with age, you are losing the buffer against the
stress-related hormones. It is the buffer action that [helps prevent] us
from aging.” The decrease of DHEA with age may result in gradual decline
of a system for suppressing enzyme systems responsible for creating the
building blocks of new cells, like lipids, nucleic acids (RNA and DNA) and
sex steroids. The resulting rise in enzymatic activity in advanced age may
be responsible for the proliferative events (cancer) and degenerative
disease that become more frequent in advanced age. In this respect, DHEA
might be best considered to be an anti-hormone, which might
“de-excite” steroid-sensitive receptors that would otherwise lead to
enhanced metabolic activity.
Dosage
Exact dosages for humans have not been clearly determined. Daily
dosages vary from 5 to 10 mg to as much as 2000 mg, with 5, 10, 25 and 250
mg being the range for typical tablet and capsule sizes. DHEA is usually
split into 2-4 daily doses, especially at the higher dosage levels.
We recommend that dosage be adjusted to bring blood DHEA and DHEA-S
measurements towards young-adult levels. These blood tests can be ordered
by your physician (don’t forget to get your first test before you
start taking DHEA).
Conclusion
Because of its generally universal function in human metabolism, DHEA
is being associated with numerous human maladies. For example, DHEA has
recently been found to have a highly statistically significant correlation
with vertebral bone density in postmenopausal women suggesting that DHEA
(and other weak androgens) may protect against osteoporosis. This, and its
low toxicity, may tend to give DHEA the same panacea stigma that the
antioxidants vitamin E and C suffer.
Regulatory Difficulties
In Europe, DHEA is already available as a drug in 5 and 10 mg doses
(although it has been hard to obtain). It is used primarily for the
treatment of menopause. In the United States, DHEA must first be approved
as a drug by the FDA before it can be marketed for medical purposes.
Unfortunately, this is an adversarial process (the drug companies
advocating for the drug and the FDA demanding proof of efficacy and
safety) which takes up to 100 million dollars and a decade to accomplish.
Without a patent to restrict competition, prices cannot be raised high
enough to recover the investment in the approval process. DHEA is an
unpatentable substance.
References
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dehydroepiandrosterone sulfate, mortality, and cardiovascular disease. New
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Bulbrook RD, Hayward JL and Spicer CC. Abnormal excretion of
urinary steroids by women with early breast cancer. Lancet 2:
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Bulbrook RD, Hayward JL and Spicer CC. Relation between urinary
androgen and corticoid excretion and subsequent breast cancer. Lancet
2: 395-98, 1971.
Chen TT, et al. Prevention of obesity in Avy/a mice by
dehydroepiandrosterone. Lipids 12: 409-13, 1977.
Cleary MP and Fisk JF. Anti-obesity effect of two
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female Zucker rats. International Journal of Obesity 10(3):
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Kahn, Carol. Beyond the Double Helix: DNA and the Quest for
Longevity, Times Books, 1985, page 143. A thorough and highly readable
“inside” account of DHEA research.
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systemic resistance against lethal Infections in mice. Annals of NY
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3H-7,12-dimethylbenz(alpha)anthracene to mouse skin DNA. J Gerontology
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dehydroepiandrosterone. Cancer Research 39: 1129-32, 1979.
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Schwartz AG, Nyce JW and Tannen RH. Inhibition of tumorigenesis
and autoimmune development in mice by dehydroepiandrosterone. Mod Aging
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Prevention of obesity in Avy/a mice by dehydroepiandrosterone. Lipids
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