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Hormones are the chemical messengers of the body.
They are produced primarily in glands and organs that
are part of the body's endocrine system. However, other organs,
such as the heart, can produce certain hormones as
needed.
Throughout the body, there are receptors matched to
specific hormones. Hormones and their receptors can be
thought of as analogous to keys and locks. When the
appropriate hormone (key) binds to a matching receptor
(lock), it enables (unlocks) the receptor allowing the
chemical message carried by the hormone to be
transmitted to the internal mechanism of a cell.
The body produces many hormones. Some act directly on
receptors, and some exist solely to control other
hormones. Glands that contain many hormone receptors are said
to be hormonally active. The prostate certainly fits
this description. Virtually all of the sex steroid
hormones have receptors on the prostate.
Much medical writing, particularly older
studies and books, support the theory that high
testosterone levels are the cause of prostate problems.
If this were so, young men whose testosterone levels are
high compared to older men, would be the primary group
affected by prostate disease. In recent studies, high
testosterone levels were not correlated to prostate
disease. In fact, many studies seem to suggest that men
with low free testosterone levels have higher risk of
developing prostate problems, including prostate cancer.
Top of page The latest research appears to
indicate that the increase in conversion of testosterone
to estradiol, and also conversion to its more active
component, DHT, rather than the overall testosterone
level, is a primary factor initiating many prostate
problems. This contradicts some widely held beliefs.
Both DHT and estradiol are necessary for proper
functioning of the prostate, but their levels can become
skewed due to nutritional deficiencies or
lifestyle/environmental issues. When they become
unbalanced with respect to the other hormones, the
problems start. The imbalance increases sensitivity of
the prostate to the estrogens. The increase in
conversion of testosterone to DHT, and increased
sensitivity to the estrogens, particularly estradiol,
appear to be significant in the development of
prostate disease.
Virtually all hormones exist in the body in two forms,
free and bound. Only free hormones are active. Bound
hormones are paired with a protein called "Sex Hormone
Binding Globulin (SHBG) and cannot bind with
receptors. SHBG also rises with advancing age. The net effect is that the age-related
decrease in total testosterone is magnified by this
increased binding to SHBG, resulting in a lessened
amount of free testosterone.
Top of page When testosterone becomes bound to SHBG, its ability to
attach to receptors is inhibited. Since only free
testosterone can deliver its hormonal message to
prostatic receptors, a rise in SHBG is significant. It
results in symptoms of low testosterone, even though
total testosterone levels may appear normal. This is a
very common condition in older men and the reason why
free and total (not just total) testosterone should
always be measured.
Low levels of free testosterone and
increased levels of SHBG tend to magnify the effects of
estradiol. Aging also causes a slight rise in estradiol,
which compounds the problem. Some research suggests that
increased levels of estradiol activate the liver to make
more estradiol. Thus, the ratio of most of the androgens
to estrogens is altered significantly, setting the scene
for prostate dysfunction. These combined effects of
elevated estradiol and SHBG, along with corresponding
lowered levels of free testosterone have a profound
effect and are significant contributors to the
development of BPH and other prostate conditions as a
man ages.
Normal levels of testosterone can vary significantly
between men. The numbers are derived from a sampling of presumed healthy men of
various ages separated into age groups
and averaged for each group. Older
men are generally at the lower end of the range. Based
on this, it is considered normal for older men to have
lower levels of testosterone. However, in many studies, it appears that prostate
problems occur more frequently in men with relatively
low testosterone levels. Thus, normal may be
quite different from optimal.
The previous accepted belief that the prostate was
responsive only to testosterone is now known to be
incorrect. The prostate is also rich in receptors for
progesterone and estrogen. While both estrogen and progesterone were
previously thought to be specifically female, with
little effect on the prostate, quite the opposite is
true.
Top of page Progesterone, in addition to its own properties, has
profound effects on the availability of all the other
sex hormones. A deficiency in progesterone inherently
results in deficiency of some of the others. As a man
ages, his progesterone production also decreases, resulting
in a corresponding decrease in his levels of
testosterone. At the same time more of his available
testosterone is converted to DHT and estradiol. The end
result is that the relative ratios of estrogen to
progesterone, and estrogen to testosterone increase.
This allows more estrogen (particularly estradiol) to
reach receptors on the prostate, thereby increasing its
overall effect. Some studies have found that
estradiol reduces the body’s clearance of DHT from the
prostate, thereby compounding the problem.
As we age, the level of another hormone, DHEA, also drops,
resulting in an additional decrease in testosterone
levels, again compounding the problem. Many recent
studies have found that both low levels of DHEA and
testosterone correspond directly to prostate problems.
Thus, the age-related drop in progesterone, DHEA, and
testosterone, and the relative rise in estrogen and SHBG
levels, results in increased risk for prostate problems.
Coincidentally, excess estradiol is also known to be a
key player in abnormal breast tissue proliferation. This
is one reason older men frequently have enlarged
breasts.
Testosterone deficiency contributes to low libido,
reduced muscle mass, reduced bone mass, erectile
dysfunction, atherosclerosis, depression, and other
problems. Adequate testosterone
levels are essential for a man to have normal libido,
orgasms, and spontaneous erections.
Unfortunately, there is no specific value to determine
what an adequate or normal level is. What is normal for
one man may be woefully insufficient for another. If
your testosterone levels fall on the low side of the
normal range and you are having symptoms of low
testosterone, herbal testosterone boosters, or
over-the-counter progesterone or DHEA creams may
help.
You can find various herbal boosters and some hormone
creams in the
Supplements section.
A more detailed explanation of hormone basics and a
diagram is in my book,
Your Prostate, Your
Libido, Your Life.
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