Dehydroepiandrosterone (DHEA)
is a hormone which serves as a
precursor for other steroid hormones
in the body. DHEA is made primarily
in the cortex of the adrenal glands.
A small amount, especially
in women, is also formed in the gonads. [1]
Pregnenalone and cholesterol are the
precursor molecules in the formation
of DHEA. Conversion of pregnenalone
to DHEA is catalyzed by the p450c17
enzyme system. Estradiol, estrone,
testosterone, and androstenedione are
made also from DHEA.
DHEA has received
popularity as an anti-aging hormone.
Sustained levels of DHEA have been
linked to longevity, and it has been postulated
that DHEA supplementation can provide
protection against the effects of
aging. After age 30, production of DHEA from the adrenal gland
progressively declines. However,
some physicians believe that DHEA is
unlikely to significantly increase
the length of a person's life. [2]
This reasoning spawns
from conflicting
research, such as a study in rats
that showed some rats live longer
when supplemented with DHEA, while
others do not. In addition, measured DHEA levels are normal in patients
with the abnormal aging condition,
Progeria. This finding is quite
significant because these patients
would show decreased levels if DHEA
were indeed a factor in aging. However,
despite the results of these
particular studies, many physicians
still believe that research has
validated the claim that DHEA may improve
the quality of a one's life.
Although DHEA
primarily serves
as a precursor for other steroid
hormones, it appears to have
other functions in the body. For
example, preliminary research has
shown that DHEA may influence immune
function and also impact muscle
metabolism. [3]
Research has also shown that
declining levels of DHEA have been
linked to numerous diseases of
lifestyle, and chronic disorders
such as; diabetes, obesity, heart disease,
arthritis, cancer, stress,
allergies, hypercholesterolemia
(high cholesterol), fibromyalgia, and
autoimmunity. Another interesting
function that is continually being
study studied is
DHEA's impact upon memory enhancement and
cognitive functioning. [4]
Perhaps the most
interesting research is regarding
the anti-glucocorticoid effects of
DHEA. [5]
It has been theorized that by acting
against glucocorticoids, including cortisol, DHEA exerts
the majority of its physiological,
biological, and biochemical effects.
Like DHEA, glucocorticoids are also produced in
the cortex of the adrenal gland and
function to raise glucose levels in
the plasma. It is primarily cortisol
that acts to maintain blood glucose
levels within normal ranges.
DHEA is a hormone
found in the human body therefore
food sources do not exist. DHEA must
be taken in supplement form. Some
supplements may contain wild yam
extract which has bee suggested to
convert to DHEA in the body. However, the validity of this
statement is uncertain. [3] Pregnenalone is also sold in
supplement form, and as mentioned
previously, it is a direct precursor of DHEA. Some people
theorize that pregnenalone may be safer than DHEA,
but there is no evidence to support
this suggestion. [3] Furthermore,
pregnenalone will eventually be converted to DHEA.
As discussed, DHEA is
often used as an anti-aging hormone and receives the most attention as a
treatment for this purpose. Research
has shown DHEA to be effective for
the treatment of systemic lupus
erythematosus (SLE). Studies have
shown that female patients given
high doses of DHEA (200mg/d) for three
months experienced improvement in
the SLE Disease Activity Index,
which is used to rate the severity
of symptoms of this condition. [6,
7] Patients taking DHEA could also
decrease their dose of
corticosteroids, while those taking
placebo actually had to increase
their dose of prescribed
medication.
The treatment of
osteoporosis with DHEA has received
some interest in clinical research. DHEA has been observed to be lower
in women with osteoporosis versus
controls. [8] A number of studies have been
conducted in postmenopausal women.
Research has
examined the effects of DHEA on
various tissues, including the bone
mineral density in this demographic. [9,
11] Significant increases in bone
mineral density were measured in
patients using either a DHEA cream
or an oral supplement.
DHEA may be used for
Alzheimer's disease, as it has been
shown to enhance memory and
cognitive function. [12-14]
It appears that slightly higher
doses than are physiological
required are
needed to obtain noticeable
effects from DHEA in this context.
Other conditions for
which DHEA may be useful include; rheumatoid arthritis, asthma,
menopausal syndrome, certain acute
lethal viral infections, and
erectile dysfunction. [15-19] Patients with bipolar disorder and
hypo-manic depression should only
take DHEA under the supervision of their
physician, due to possible
aggravations of the disorders.
The dosage of DHEA
from supplementation varies
and is, largely, dependant upon what disorder
or dysfunction is being treated. Because of
potential side effects
and toxicities (see below), DHEA
supplementation should only be taken
under physician supervision. As
well, physicians will have access to
reliable, safe sources of the
supplement.
For patients with
measured low levels of serum DHEA, a
physiological dose should be
prescribed. This equates to
approximately 5-10
milligrams per day in women, and
10-20 milligrams per day in men.
Doses may be slightly modified
based on individual blood levels. It
is suggested that the only
time women under forty take DHEA is when they have measurably
low DHEA levels in their blood, or if they
are being treated for a particular
disorder (e.g. autoimmune disease, rheumatoid arthritis). [2] Actually, as women approach
menopause, DHEA levels increase.
Therefore, it is even more important
to perform lab tests because
excessive DHEA will cause virilism
(facial hair growth and acne).
Supplementation for
the treatment of diseases such as
osteoporosis or autoimmune disease
is in the range of 50 - 100 milligrams
daily. This level of DHEA therapy
may cause acne in some women during the
first few weeks that therapy is
initiated.
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DHEA Toxicities and
Deficiencies |
DHEA Deficiency
DHEA and DHEA-S
(sulfate) can be tested by measuring
blood serum levels. If low
levels are observed, a patient can
be treated with a physiological dose
of DHEA. Generally, DHEA declines
with age and clinicians have
observed that supplementation at a
physiological dose can promote an
increase in the perception of mental
and physical well-being in these
adults. [1] Men may
suffer from fatigue and/or low
libido as a result of a DHEA
deficiency.
DHEA Toxicities
DHEA supplementation
in high doses can cause problems, such as impairment of the body's
ability to biosynthesize its own DHEA. [20]
High dose DHEA can also be toxic to
the liver and result in hepatic
damage from oxidative destruction. Animal studies have
also demonstrated the
development of hepatocellular
carcinomas. [21] To minimize this type of damage, DHEA supplements should be taken
with antioxidants, especially vitamins C
and E, and selenium. Excessive
amounts of DHEA have also been
linked to breast and prostate
cancers. [3]
Common side effects
include oily skin, acne, excessive hair growth (in women), and
heart palpitations. Excessive
amounts of DHEA has also
been linked to aggravations of bipolar
disorder and hypo-manic depression.
Patients with Grave's
disease who have thyrotoxicosis
should take DHEA with caution,
as it has been shown to increase the
action of thyroid hormone. Caution
should also be exercised if taking Synthroid (L-thyroxine), or other
supplemental thyroid hormones.
The following table lists various
products that contain a safe and
reliable source of DHEA:
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