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It is important to note that significant amounts of DHEA are made only by humans and
primates. Rodents, such as mice or rats, have little circulating DHEA in their blood so
any dose given them would be a pharmacological dose.
Unfortunately, most studies involving DHEA have been con- ducted with rodents and many of
the "miracle" claims being touted for DHEA have been based upon rodent studies.
Much of the extrapolation from rodent studies to humans may be contradictory and, in fact,
some of it has been proven to be false!
The information and recommendations provided within this report have been based upon the
latest studies conducted on human subjects.
Aging Biomarker
DHEA is a steroid hormone produced by the adrenal glands in both men and women.7
This hormone is considered a key biomarker in determining biological age as it cycles on a
life scale in both sexes. It is the only hormone that peaks early in life and starts to
fall significantly thereafer.8
DHEA is highest during the years of top physical condition, rising rapidly just before
puberty, then spiking between ages twenty and twenty-five. It begins declining
progressively from that point forward, reaching a low by the age of sixty and then slowly
descends to less than five percent of peak adult levels after age 70.9
The clear drop in men past forty is in sharp contrast to testosterone, which declines
noticeably in men only after age sixty.10
During the peak years between 25 and 30, men are believed to make 1 to 2 mg of DHEA and 10
to 15 mg of DHEAS per day, with women making somewhat lower amounts.11
It is believed that approximately half of the androgen and estrogen precursors in the
human body comes from the adrenal glands' production of DHEA.12 As a result,
the decline in DHEA production by the body reflects itself in the cells.
Based upon the foregoing, it has been suggested that supplementation with DHEA for those
individuals 40 and older, bringing their levels back to those of youth, could extend
longevity and improve the quality of life.
This suggestion gains further support in that DHEA, unlike other steroids, does not appear
to be regulated by a "feed- back loop". DHEA supplements -except in very high
dosages-
are not likely to stop the body's own production.13
Autoimmunity
There are many autoimmune conditions of which systemic lupus erythematosus (SLE) is four
times as common in women as in men. Symptoms include painful swollen joints, skin rash,
and mouth ulcers.
SLE is more common than previously thought. A study in England found that 200 women out of
100,000 reported symptoms indicative of the illness.14
A team of medical researchers from Japan determined that patients with SLE had low DHEA
activity.15
Physicians at Stanford University Medical Center conducted a study with ten female
patients with mild to moderate SLE. The subjects were given 200 mg of DHEA daily for 6
months.
Following DHEA therapy, most of the symptoms were improved. The researchers concluded:
DHEA shows promise as a new therapeutic agent for the treatment of mild to moderate
SLE.16
It is believed that DHEA therapy could benefit other auto-immunity diseases such as
rheumatoid arthritis and multiple sclerosis. However, the studies on lupus have been the
only well-controlled ones thus far. Further studies are clearly warranted.
Brain Enhancement
Researchers from the San Diego Medical School evaluated 13 men and 17 women who ranged in
age from 40 to 70 years. In a placebo-controlled, cross-over trail, they provided 50 mg of
DHEA nightly for 3 months.
Within two weeks, the DHEAS levels in the bloodstreams of those receiving supplements
reached those found in young adults. The researchers concluded:
DHEA supplementation resulted in an increase in perceived physical and psychological
well-being for both men and women. The subjects reported increased energy, a better mood,
and an improved ability to deal with stressful situations.17
DHEA has also been found to have a positive effect on memory. When 50 mg of DHEA was
administered to subjects an hour before bed, there was a significant increase in recorded
REM (dream) sleep for two hours afterward. Dreams are thought to facilitate memory
consolidation.18
Cancer
The majority of the research evaluating the role of DHEA in cancer has been done on
rodents. Very little is known about its role in cancer prevention in humans.
As stated earlier in this report, the results of experiments involving rodents can be very
different from results of similar studies with human subjects, especially since very
little DHEA is found in the bloodstream of rodents.
DHEA levels can predict which women will get breast cancer up to nine years in
advance,19
and this steroid actually counteracts a well-known cancer-causing substance known as 12-0-
tetradecanoyl-phorbol-13-acetate.20
Whether long-term DHEA therapy will help prevent cancer in humans is undetermined at this
time.
Diabetes
As humans age, the tissues develop a resistance to insulin and the glucose remains in the
blood at a higher level. In a recent study 50 mg of DHEA was given daily for three weeks
to 11 postmenopausal women.21 The levels of triglycerides declined and DHEA
enhanced tissue insulin sensitivity.
Another study also confirmed significant improvement in insulin sensitivity.22
The researchers concluded: DHEA replacement may help attenuate age-related increases in
insulin resistance.
It appears probable that DHEA has a positive effect in type II adult onset diabetes.
Heart Disease (CVD)
A study involving 49 males younger than age 56 who were survivors of a heart attack were
compared to 49 other males of the same age group who had not experienced heart attacks.
Those with prior heart attacks had significantly lower levels of DHEAS than the control
group.23
The researches concluded that serum DHEAS levels are inversely related to premature
myocardial infarction in males and that this association is independent of the effects of
several known risk factors for premature myocardial infarction.
Another study correlating DHEAS blood levels with the level of premature atherosclerosis
in 206 patients under age 50 found that the levels of DHEAS were lower in the men who had
coronary artery disease than the control group. This data lends further support to
clinical studies suggesting that DHEA may play an important role in the pathogenesis of
coronary disease.24
A current study of 1,700 men aged 40 to 70 who had their DHEAS levels tested indicated
those with the lowest levels were the most likely to have had heart disease, even after
controlling for other risk factors such as smoking and diet.25
Clinical studies thus far confirm that high DHEA(S) levels are protective of heart disease
in men, but not as influential in women. It is probable, however, that supplementation
with DHEA can slow the onset of coronary artery disease.
Immune System
A study was conducted of nine healthy men with an average age of 64 years. Each was given
50 mg of DHEA for 20 weeks at which time it was found that DHEA therapy had significantly
elevated natural killer cells that fight infections.26
Another clinical study vaccinated a group of elderly volunteers (over 65 years of age)
with the influenza vaccine and compared them to another group similarly vaccinated but who
had also received 50 mg of DHEAS for two consecutive days beginning on the day of the
vaccination. The elderly who got the DHEAS had a significant improvement in their ability
to develop anti-bodies to the influenza vaccine.27
In short term studies on human subjects, DHEA has been found to be beneficial as a
supplement in older individuals by improving the immune system.
Libido
DHEA may influence women more strongly than men where sexual desire is concerned. DHEA's
favorable association with sex drive in women was demonstrated in a Crenshaw Clinic
research protocol.28 Increased levels of DHEA were associated with increased
sexual desire.
Only in women, in marked contrast with other mammals, can the ovaries be removed without a
predictable reduction of sexual desire. From this, researchers have concluded that human
female sexual desire has shifted somewhat from estrogens to androgens like DHEA, and from
the ovaries to the adrenals.29
In men, the positive effects of DHEA are most apparent in those who have low androgen
levels.30,31 for men, cardiovascular disease and stress are the
greatest causes of sexual dysfunction.
DHEA blood levels drop drastically under stress, which is one of the primary reason that
sex drive may decrease with acute or chronic stress, (and why men may lose erections when
they worry about performance).32
It is clear from numerous studies that DHEA does boost sex drive, especially in those who
have low DHEAS levels.
Muscle Building
Aging is associated with a gradual shift from a young state characterized by anabolism,
the building-up of muscles and tissues, to an aged state characterized by catabolism, the
loss of muscle mass and strength.33
DHEA in appropriate replacement doses appears to have remedial effects with respect to its
ability to induce an anabolic growth factor, increase muscle strength and lean body mass
in aging men and women, with no significant side effects.34
Ninety-six patients with coronary artery disease had their DHEAS levels measured prior to
starting a controlled exercise program. After 12 weeks, there was no change in the levels
of DHEA leading researchers to conclude that exercise training alone has no significant
impact on DHEAS.35
In an earlier study conducted at the University of Rochester in New York, eight healthy
young men were given 1,600 mg of DHEA for 4 weeks. The researchers found that DHEA had
little influence on energy or protein metabolism.36
DHEA in appropriate doses does appear to increase muscle strength and lean body mass in
older men and women. However, it has little or no anabolic affect on younger men with
normal DHEA blood serum levels and high dosage use by bodybuilders should be discouraged.
Osteoporosis
In surgical menopause with the removal of the uterus and ovaries, osteoporosis can occur
within two years. After four years, over 60% of women demonstrate osteoporosis because of
estrogen deprivation.37
Research conducted in Japan on 120 postmenopausal women 51 to 99 years old found that
women with higher DHEAS levels were more likely to have stronger bones.38
Results of such studies demonstrate that DHEA is converted to estrone in
osteoblasts, and
this is important in maintaining bone mineral density after menopause.39
DHEA therapy has the potential to influence stronger bone formation, especially in
postmenopausal women.
Weight Loss
The reports in the medical literature evaluating the relationship of DHEA to weight loss
have not been inconsistent.
Studies conducted in 198840 and 199141 under Dr. Nestler at the
Medical College of Virginia in Richmond "suggest that DHEA may possess hypolipidemic
and, possibly, anti-obesity properties".
Similar independent studies conducted by Dr. Usiskin42 and Dr. Welle43
in 1990 concluded that short-term administration of DHEA, in high doses, did not have much
of an influence on weight.
Recent epidemiological studies conducted this year also do not support the theory, based
upon rodent studies, that high DHEA(S) levels protect against obesity.44
It appears unlikely that DHEA, regardless of dosage, will facilitate weight loss, however,
DHEA may potentially be combined with other weight loss nutrients and herbs to have a
synergistic effect. More research needs to be conducted.
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