TESTOSTERONE AND AGING.

This material for this article was drawn from the November issue 1999 of the Life Extension Foundation Journal.

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 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. 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 drive 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.

Herbs and male sexual potency

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.

 Chrysin, for example, is also a potent antioxidant that possesses vitamin-like effects in the body. It has been shown to induce an anti-inflammatory effect.,

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 as well as "sexual performance anxiety" that prevents them from being able to achieve erections when they are expected to. 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.

Chrysin may therefore offer libido-enhancing effects in the aging male by:

•  Increasing free testosterone
•  Decreasing excess estrogen
•  Producing a safe anti-anxiety effect.

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Nettle Root Extract

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.

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.

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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.

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Testosterone

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.

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.

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.