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Plant extracts
favorably alter hormone metabolism and improve sexual desire in menThrough
a variety of mechanisms, aging men suffer from the dual effects of
having too little testosterone and excess estrogen. The result is a
testosterone/ estrogen imbalance that can severely inhibit sexual desire
and performance. In youth, low amounts of estrogen are used to turn off
the powerful cell-stimulating effects of testosterone. As estrogen
levels increase with age, testosterone cell stimulation may be locked in
the "off" position, thus reducing sexual arousal and sensation and
causing the common loss of libido so common in aging men. The
genital/pelvic region is packed with testosterone receptors that are
ultra-sensitive to free testosterone-induced sexual stimulation.
Clinical studies using testosterone injections, creams or patches have
not always provided a long-lasting libido enhancing effect in aging men.
We now know why. Aging men sometimes convert testosterone to estrogen.
The estrogen is then taken up by testosterone receptor sites in cells
throughout the body. When an estrogen molecule occupies a testosterone
receptor site on a cell membrane, it blocks the ability of serum
testosterone to induce a healthy hormonal signal. It does not matter how
much serum free testosterone is available if excess estrogen is
competing for the same cellular receptor sites. Testosterone is a
hormone responsible for sex drive in both men and women. For
testosterone to promote youthful sexual interest, satisfaction and
performance, it must be freely available to cell receptor sites in the
brain, the nerves, muscles and genitals. As people age, testosterone
becomes bound to serum globulin and is not available to the cell
receptor sites were it is needed to initiate sex stimulating centers in
the brain. The component in the blood that renders free testosterone
inactive is called sex hormone-binding globulin (SHBG). Excess estrogen
can increase the production of SHBG and block testosterone-receptor
sites. This means there are two mechanisms by which excess estrogen
interferes with sex dive in aging males. For testosterone to produce
long-lasting libido enhancing effects, it must be kept in the "free"
form in the bloodstream. Bound testosterone is not able to be picked up
by testosterone receptors on cell membranes. For aging men, it is
desirable to suppress excess levels of SHBG and estrogen while boosting
free testosterone to the level of a young man. There is now a natural
way of modulating testosterone and estrogen levels in aging men that
does not require expensive prescription drugs. Restoring youthful
hormone balance can have a significant impact on male sexuality. To
reiterate, the hormone modulation objectives that most aging men need to
facilitate sexual rejuvenation involves an increase in "free"
testosterone coupled by a decrease in both estrogen and SHGD levels.
Increasing
testosterone by suppressing excess estrogen
For many men, a safe and easy way to increase free
testosterone is to prevent it from being converted (aromatized) into
excess estrogen. Too much estrogen plays havoc with a man's sex life by
binding to testosterone receptor sites and may contribute to the
over-production of SHBG. SHBG binds free testosterone in a way that
makes it unavailable to receptor sites in the brain, nerves and
genitals. Estrogen overload is a serious problem in aging men. One
report showed that estrogen levels of the average 54-year-old man are
higher than those of the average 59-year-old woman. Estrogen is a
necessary hormone for men, but too much causes a wide range of health
problems. High serum levels of estrogen also trick the brain into
thinking that enough testosterone is being produced, thereby slowing the
natural production of testosterone. Based on the multiple deleterious
effects of excess estrogen in men, aggressive actions should be taken to
reduce estrogen to a safe range. To determine if estrogen levels are too
high, men are encouraged to have their blood tested for estradiol. If
the blood test results show estradiol levels are greater than 30 pg/mL,
men should consider radical lifestyle changes, and/or taking an
aromatase-inhibiting nutrient or drug. A numerical example of the
effects of a nutritional aromatase inhibitor can be seen on one of the
subjects in the pilot studies whose initial serum estradiol level was a
high 54 and free testosterone a moderately low 14.4. After only 30 days
on a nutritional aromatase inhibitor, estradiol levels fell to 36 (from
54) and free testosterone levels increased to 22.5 (from 14.4). In this
pilot study, funded by The Life Extension Foundation, 9 of 10 test
subjects showed a significant decline in excess estrogen levels when
several herbal extracts were combined. These kinds of results show how
some men reduce excess estrogen while boosting free testosterone.
Herbs and male sexual
potency
There are herbal extracts that have been shown to
either increase or decrease testosterone levels. The New England Journal
of Medicine (1998, 339;785-91) showed that an herbal preparation called
PC Spes had the dual effect of suppressing testosterone and increasing
estrogen and was therefore beneficial in the treatment of prostate
cancer. Conversely, herbs that increase free testosterone and suppress
excess estrogen are highly desirable for healthy men over age 40 who
suffer the premature aging effects of a testosterone deficit, including
loss of libido. We discuss some of these herbal extracts here.
Chrysin
A bioflavonoid called chrysin has shown potential
as a natural aromatase-inhibitor. Chrysin can be extracted from various
plants. Body builders have used it as a testosterone boosting
supplement. The problem with chrysin is that because of its poor
absorption into the bloodstream, it has not produced the testosterone
enhancing effects users expect. In a study published in Biochemical
Pharmacology (1999, Vol.58), the specific mechanisms of chrysin's
absorption impairment were identified, which infers that the addition of
a pepper extract (piperine) could significantly enhance the
bioavailability of chrysin. Pilot studies have found that when chrysin
is combined with piperine, reductions in serum estrogen (estradiol) and
increases in total and free testosterone result in 30 days.
Aromatase-inhibiting drugs are used to treat women with
estrogen-dependant breast cancers. The rationale for this therapy is
that estrogen is produced by fat cells via a process known as
aromatization. Aging men often have excess aromatase enzyme activity,
and the result is that too much of their testosterone is "aromatized"
into estrogen. In a study published in the Journal of Steroid
Biochemical Molecular Biology (1993;Vol 46, No 3), chrysin and 10 other
flavonoids were compared to an aromatase-inhibiting drug
(aminoglutethimide). The study tested the aromatase-inhibiting effects
of these natural flavonoids (such as genistein, rutin, tea catechins,
etc.) in human fat cell cultures. Chrysin was the most potent
aromatase-inhibitor, and was shown to be similar in potency and
effectiveness to the aromatase-inhibiting drug. The scientists
conducting the study concluded by stating that the aromatase-inhibiting
effects of certain flavonoids may contribute to the cancer preventive
effects of plant-based diets. Two recent studies have identified
specific mechanisms by which chrysin inhibits aromatase in human cells.
These studies demonstrate that chrysin is a more potent inhibitor of the
aromatase enzyme than phyto-estrogens and other flavonoids that are
known to have aromatase-inhibiting properties (Arch Pharm Res 1999
Jun;22(3):309-12; J Steroid Biochem Mol Biol 1997 Apr;61(3-6):107-15).
The purpose of these studies was to ascertain which fruits and
vegetables should be included in the diet of postmenopausal women to
reduce the incidence of breast cancer. Excess levels of mutagenic forms
of estrogen have been linked to a greater risk of breast cancer, and
scientists are studying dietary means of naturally reducing levels of
these dangerous estrogens. Flavonoids such as chrysin are of
considerable interest because they suppress excess estrogen via their
aromatase-inhibiting properties. While this cancer preventing effect is
most important for women, inhibiting aromatase in aging men has
tremendous potential for naturally suppressing excess estrogen while
boosting low levels of testosterone to a youthful state. Since chrysin
is not a patentable drug, don't expect to see a lot of human research
documenting its effects. There are lots of FDA approved drugs that
inhibit aromatase (such as Arimidex), and there is not much economic
interest in finding natural ways of replacing these drugs. While
prescription aromatase-inhibiting drugs are relatively free of side
effects, aging men who are seeking to gain control over their sex
hormone levels often prefer natural sources, rather than trying to
convince a physician to prescribe a drug (such as Arimidex) that is not
yet approved by the FDA as an anti-aging therapy. (Arimidex is
prescribed to estrogen-dependant breast cancer patients to prevent
testosterone and other hormones in the body from converting, i.e.
aromatasing, into estrogen.) An advantage to using plant extracts to
boost testosterone in lieu of drugs is that the plant extracts have
ancillary health benefits. Chrysin, for example, is a potent antioxidant
that possesses vitamin-like effects in the body. It has been shown to
induce an anti-inflammatory effect, possibly through inhibition of the
enzymes 5-lipoxygenase and cyclooxygenase inflammation pathways. Aging
is being increasingly viewed as a pro-inflammatory process, and agents
that inhibit chronic inflammation may protect against diseases as
diverse as atherosclerosis, senility and aortic valve stenosis. Chrysin
is one of many flavonoids being studied as a phyto-extract that may
prevent some forms of cancer. If chrysin can boost free testosterone in
the aging male by inhibiting the aromatase enzyme, this would provide
men with a low cost natural supplement that could provide the dual
anti-aging benefits of testosterone replacement and aromatase-inhibiting
drug therapy. As previously discussed, boosting free testosterone levels
can have a dramatic effect on sex drive, performance and satisfaction.
Pilot studies indicate that chrysin increases total and free
testosterone levels in the majority of men who take it with piperine.
Chrysin has one other property that could add to its libido-enhancing
potential. A major cause of sexual dissatisfaction among men is
work-related stress and anxiety. Another problem some men have is
"sexual performance anxiety" that prevents them from being able to
achieve erections when they are expected to. In a study published in
Pharmacology Biochemistry and Behavior (1994, Vol 47), mice were
injected with diazepam (Valium), chrysin or placebo to evaluate the
effects these substances had on anxiety and performance levels. Chrysin
was shown to produce anti-anxiety effects comparable with diazepam, but
without sedation and muscle relaxation. In other words, chrysin produced
a relaxing effect in the brain, but with no impairment of motor
activity. The mechanism of action of chrysin was compared to diazepam,
and it was shown that unlike diazepam, chrysin can reduce anxiety
without inducing the common side-effects associated with benzodiazepine
drugs. A common problem with benzodiazepine drugs is memory impairment.
In a study published in a 1997 issue of Pharmacology Biochemistry and
Behavior (Vol 58, No 4), chrysin displayed potent anti-anxiety effects
in rats, but did not interfere with cognitive performance. In this
study, diazepam was shown to inhibit neurological function, but chrysin
(and other anti-anxiety flavonoids) had no effect on training or test
session performance. The scientists conducting this study pointed out
that chrysin selectively inhibits anxiety in the brain but, unlike
diazepam, does not induce the cognitive impairment. Chrysin may
therefore offer libido-enhancing effects in the aging male by: -
Increasing free testosterone, - Decreasing excess estrogen, - Producing
a safe anti-anxiety effect. Chrysin is being sold to body builders by
commercial supplement companies that do not know if their product is
favorably modulating testosterone and estrogen levels in men. The Life
Extension Foundation, on the other hand, has conducted meticulous
studies to evaluate the effects of chrysin (combined with piperine to
facilitate absorption) on aging men. These studies have produced some
impressive preliminary data, and ongoing research will be reported in
future issues of Life Extension magazine.
Nettle
About 90% of testosterone is produced by the
testes, the remainder by the adrenal glands. Testosterone functions as
an aphrodisiac hormone in brains cells, and as an anabolic hormone in
the development of bone and skeletal muscle. But testosterone that
becomes bound to serum globulin is not available to cell receptor sites
and fails to induce a libido effect. It is, therefore, desirable to
increase levels of "free testosterone" in order to ignite sexual arousal
in the brain. As discussed already, a hormone that controls levels of
free testosterone is called sex hormone-binding globulin (SHBG). When
testosterone binds to SHBG, it loses its biological activity and becomes
known as "bound testosterone," as opposed to the desirable "free
testosterone." As men age past year 45, SHBG's binding capacity
increases almost dramatically-by 40% on average-and coincides with the
age-associated loss of libido. Some studies show that the decline in
sexual interest with advancing age is not always due to the amount of
testosterone produced, but rather to the increased binding of
testosterone to globulin by SHBG. This explains why some older men who
are on testosterone replacement therapy do not report a long-term
aphrodisiac effect. That is, the artificially administered testosterone
becomes bound by SHBG, and is not bioavailable to cellular receptor
sites where it would normally produce a libido-enhancing effect. It
should be noted that the liver also causes testosterone to bind to
globulin. This liver-induced binding of testosterone is worsened by the
use of sedatives, anti-hypertensives, tranquilizers and alcoholic
beverages. The overuse of drugs and alcohol could explain why some men
do not experience a libido-enhancing effect when consuming drugs and
plant-based aphrodisiacs. An interesting review, "How Desire Dies"
(Nature, 381/6584, 1996), discusses how frequently prescribed drugs,
such as beta-blockers and antidepressants, cause sexual dysfunction.
Prescription drugs of all sorts have been linked to inhibition of
libido. Logically, one way of increasing libido in older men would be to
block the testosterone-binding effects of SHBG. This would leave more
testosterone in its free, sexually activating form. A highly
concentrated extract from the nettle root provides a unique mechanism
for increasing levels of free testosterone. Recent European research has
identified constituents of nettle root that bind to SHBG in place of
testosterone, thus reducing SHBG's binding of free testosterone. As the
authors of one study state, these constituents of nettle root "may
influence the blood level of free, i.e. active, steroid hormones by
displacing them from the SHBG bindings site." The prostate gland also
benefits from nettle root. In Germany, nettle root has been used as a
treatment for benign prostatic hyperplasia (enlargement of the prostate
gland) for decades. A metabolite of testosterone called
dihydrotestosterone (DHT) stimulates prostate growth, leading to
enlargement. Nettle root inhibits the binding of DHT to attachment sites
on the prostate membrane. Nettle extracts also inhibit enzymes such as 5
alpha reductase that cause testosterone to convert to DHT. It is the DHT
metabolite of testosterone that is known to cause benign prostate
enlargement, excess facial hair and hair loss at the top of the head.
Muira puama
French scientists have identified an herbal
extract that has shown libido enhancing effects in two human clinical
studies. Muira puama comes from the stems and roots of the Ptychopetalum
olacoides plant, and is widely used in the Amazon region of South
America as an aphrodisiac, tonic and cure for rheumatism and muscle
paralysis. Muira puama has been the subject of two published clinical
studies conducted by Dr. Jacques Waynberg, an eminent medical sexologist
and author of 10 books on the subject. The first study, conducted at the
Institute of Sexology in Paris under Waynberg's supervision, was
reported in the November 1994 issue of The American Journal of Natural
Medicine. The study population consisted of 262 men complaining of lack
of sexual desire, or inability to attain or maintain erection. After two
weeks, 62 percent of patients with loss of libido rated the treatment as
having a dynamic effect, while 52 percent of patients with erectile
dysfunction rated the treatment as beneficial. The article goes on to
compare muira puama favorably to yohimbine, stating, "Muira puama may
provide better results than yohimbine without side effects." Dr.
Waynberg's second study, entitled "Male Sexual Asthenia," focused on
sexual difficulties associated with asthenia, a deficiency state
characterized by fatigue, loss of strength, or debility, all symptoms of
a testosterone deficiency. The study population consisted of 100 men
over 18 years of age who complained of impotence or loss of libido, or
both. A total of 94 men completed the study and were evaluated. Muira
puama treatment led to significantly increased frequency of intercourse
for 66% of couples. Of the 46 men who complained of loss of desire, 70%
reported intensification of libido. The stability of erection during
intercourse was restored in 55% of patients and 66% of men reported a
reduction in fatigue. Other beneficial effects included improvement in
sleep and morning erections. Treatment with muira puama was much more
effective in cases with the least psychosomatic involvement. Of the 26
men diagnosed with common sexual asthenia without noticeable sign of
psychosomatic disorder, the treatment was effective for asthenia in 100%
of cases, the lack of libido in 85% of cases, and for inability of
coital erection in 90% of cases. The latter finding confirms that broad
tonic action of muira puama on conditions of fatigue and stress related
sexual dysfunction. Since muira puama is not an artificial stimulant, it
fortifies the system over a period of time. Some men report increased
vitality within two weeks, while the full effects build over several
weeks. Dr. Waynberg notes that his toxicology studies and observations
corroborate the conclusions of the scientific literature on the absence
of toxicity of muira puama, which is well tolerated by men in general
good health. One of the earliest scientific studies of muira puama was
conducted by another French doctor, Dr. Rebourgeon. His research found
the plant to be effective in "gastrointestinal and circulatory asthenia
as well as impotence." Three of the most respected scientific
authorities on medical herbalism recommend muira puama. In newly
published books, James Duke, Ph.D., Chief of the United States
Department of Agriculture's Medical Plant Laboratory, and Michael
Murray, M.D., recommend muira puama for erectile dysfunction or lack of
libido. In addition, Daniel Mowrey, Ph.D., states the following in his
book Herbal Tonic Therapies (p. 358): Few in number are the plants that
seem to have a reliable reputation as true aphrodisiacs. . . . Snake oil
remedies abound, and confusion, dishonesty and hyped-up placebo
razzmatazz carry the day. Out of this mess, one plant, virtually unknown
to most Americans, appears to have risen above the competition. The
plant is called muira puama. And though not much is known scientifically
about the plant, all indications would lead one to believe that here is
a material with the potential for making an important and significant
contribution to the health of the male reproductive system. Based on the
clinical reports documenting the libido and energy enhancing effects of
muira puama, it is possible that this herb induces these positive
changes by favorably altering the hormone balance in aging men, i.e.
increases free testosterone and/or suppresses excess estrogen.
Putting it all
together
Enhanced sexual enjoyment is of paramount
importance to a great many people, increasingly so as we age. An
enormous amount of published data documents the libido-enhancing effects
that occur when testosterone is restored to a youthful level.
Testosterone is much more than a sex hormone. There are testosterone
receptor sites in cells throughout the body, most notably in the brain
and heart. Youthful protein synthesis for maintaining muscle mass and
bone formation requires testosterone. Testosterone improves oxygen
uptake throughout the body, helps control blood sugar, regulate
cholesterol and maintain immune surveillance. The body requires
testosterone to maintain youthful cardiac output and neurological
function. Men suffering from depression often have lower levels of
testosterone than control subjects. For some men, elevating free
testosterone levels could prove to be an effective anti-depressant
therapy. There is a scientific basis for free testosterone levels being
measured in men suffering from depression and replacement therapy
initiated if free testosterone levels are low normal or below normal.
One of the most misunderstood hormones is testosterone. Body builders
tarnished the reputation of testosterone by putting large amounts of
synthetic testosterone drugs into their young bodies. Synthetic
testosterone abuse can produce detrimental effects, but this has nothing
to do with the benefits a man over age 40 can enjoy by properly
restoring his natural testosterone to a youthful level. The many health
benefits of hormone modulation therapy in aging men is the subject of
these books authored by highly respected medical doctors: Vitality and
Potency, by Jonathan V. Wright, M.D. and Lane Lenard, Ph.D. and The
Testosterone Syndrome, co-authored by Eugene Shippen, M.D. These books
provide meticulous molecular details, along with many case histories
relating to the sexual enhancing effects that occur when free
testosterone is increased beyond normal "middle-aged" levels. In the
November 1999 issue of this publication, an in-depth article described
complex pharmaceutical methods of increasing free testosterone using FDA
approved drugs. Many members, however, inquired about natural ways of
increasing testosterone while suppressing excess estrogen. Ongoing
research at The Life Extension Foundation has resulted in several plant
extracts being identified that appear to increase free testosterone and
suppress excess estrogen in most men. In addition, clinical studies on
one of these plant extracts indicates a significant libido-enhancing
effect in the majority of men in placebo-controlled trials. Men over age
40 now have the option of using testosterone patches or creams that need
to be prescribed by their physician, or they can try a new combination
of plant extracts that have shown promising results. Results from
published studies continue to substantiate the critical role that
testosterone plays in protecting against premature aging. Life Extension
magazine readers will be kept informed on scientifically validated
testosterone enhancing strategies in future issues.
Excess Estrogen and
age-associated immune dysfunction
It is well known that aging results in the
shrinkage of the thymus gland, along with a reduction in the secretion
of thymic hormones and T-cells, all of which are essential for
maintaining youthful immune synchronization. A study published in the
journal Immnological Reviews (1997, Vol 160) showed that excess estrogen
may be the primary sex hormone responsible for age-induced thymic
involution (shrinkage) and age-associated immune dysfunction. The name
of this extensive study was "Thymic Aging and T-Cell Regeneration," and
it suggested that hormone modulation was one way of accomplishing thymic
regeneration. A chapter from the 1998 textbook Principles and Practices
of Geriatric Medicine entitled "Immunity and Aging" also discussed the
role sex steroid hormones play in thymic involution. These studies
suggest that restoring youthful sex hormone profiles could assist in
protecting against immune impairment caused by the shrinking thymus
gland.
Hormone modulating
nutrients: the studies
As described in the November 1999 issue of Life
Extension magazine, there are testosterone drugs and estrogen
suppressing drugs that can be prescribed by your doctor. Understandably,
however, some people do not want to use drugs if nutrients can
accomplish the same objective. In order to ascertain the safety and
efficacy of various nutrients that are purported to modulate male
hormone levels, The Life Extension Foundation has been sponsoring
clinical studies to assess the effects of specific supplements on blood
levels of testosterone, estrogen, SHBG, etc. The results from the first
pilot study showed that nine out of 10 men experienced a significant
reduction in serum estradiol (estrogen) levels after only thirty days,
compared to baseline. In this brief study, total testosterone increased
in seven out of 10 men, but free testosterone increased in only four of
the 10 men studied. Other blood parameters were not statistically
altered. A more comprehensive study incorporating a different
combination of nutrients resulted in 8 out of 8 men experiencing
increases in free testosterone while levels of the undesirable SHBG
declined in seven out of eight men, compared to baseline. Estrogen and
other blood parameters were not significantly altered in this study. A
third study was undertaken to evaluate still another combination of
nutrients. It revealed that after thirty days, 12 out of 17 men
experienced an increase in total testosterone and 11 out of 17 showed an
increase in free testosterone, compared to baseline. Again, other blood
parameters were not significantly altered. Clinical trials are ongoing,
and are expected to continue into early year 2000.
Medical Testing
For the average male over age 40, increasing free
testosterone can restore the sexual fire of youth. The only downside to
increasing free testosterone levels to those of a healthy 21-year-old is
the potential effects it may have on men with prostate cancer. Before
embarking on a testosterone-enhancement program a baseline blood PSA
test and a digital rectal exam taken to rule out existing prostate
cancer. When using testosterone drugs, PSA blood tests should be taken
every 30-45 days for the first five months to rule out hidden prostate
cancer. When using slower acting testosterone boosting nutritional
supplements, PSA testing can be reduced to every 60-90 days for the
first eight months. Remember, the preponderance of the published
literature shows that increasing free testosterone does not increase the
risk of cancer in healthy men, but those with existing prostate cancer
should avoid testosterone boosting drugs and supplements.
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