For men who choose not to (or are advised not to) use hormone replacement therapy, nutrients can play a vital role in a comprehensive program designed to reduce the impact of aging on sex hormone production and metabolism. The following is a list of nutrients that are part of Life Extension's comprehensive male hormone restoration program.
Essential nutrients for optimal testosterone production:
This mineral is involved in almost every aspect of male reproduction, including testosterone metabolism, sperm formation, and sperm motility (Ali et al 2005). A prime example of the usefulness of zinc was illustrated in a study of 37 infertile men with decreased testosterone levels and associated low sperm counts (Netter et al 1981). The men were given 60 mg of zinc daily for 45-50 days. In the majority of patients, testosterone levels significantly increased and mean sperm count rose from 8 million to 20 million. Some men require higher levels of zinc to adequately suppress aromatase.
DHEA is an important hormone that tends to be depleted steadily with age (Basar NM et al 2005). A 2006 study assessing DHEA supplementation in men of average 65 years of age found that the men experienced significant increases in testosterone and significant decreases in low-density lipoprotein (Martina et al 2006).
Tribulus terrestris, also known as puncture vine, contains the active ingredient protodioscin, which is reportedly converted to DHEA in the body (Adimoelja A 2000). This DHEA-boosting activity may account for puncture vine’s reputation as an aphrodisiac in its native Europe and Asia. Animal studies appear to confirm the ability of tribulus to improve sexual function (Gauthaman et al 2003; Milasius et al 2009).
One reason testosterone production may decline with advancing age is oxidative damage in the tissues that produce testosterone. A study examining the role of antioxidants in male hormone imbalance in aging men noted that antioxidant supplements (including vitamins A and E, zinc and selenium) all supported testosterone production (He et al 2005).
Natural products keep aromatase and/or sex hormone-binding globulin (SHBG) in check:
The bioflavonoid chrysin is a natural aromatase inhibitor (Kellis et al 1984). Bodybuilders have used chrysin as a testosterone-boosting supplement, because it minimizes the conversion of testosterone to estrogen. Although chrysin has low oral bioavailability (Walle et al 2001), its bioavailability may be significantly enhanced by co-administration with the black pepper extract, piperine, thus enhancing its actions as an aromatase inhibitor (Srinivasan et al 2007).
One study showed that red wine inhibits aromatase, thus inhibiting the conversion of testosterone to estrogen. The study attributed this effect to the quercetin and other ingredients (Eng et al 2002).
Lignans contained in nettle root extract may help prevent the binding of sex hormone-binding globulin to testosterone. This may help ensure that free testosterone is available for promoting male vitality and youthful sexual function (Anon 2007, Chrubasik et al 2007). Nettle root extract is used extensively, either incombination with saw palmetto (Lopatkin 2005) or by itself (Safarinejad 2005) for relief of BPH symptoms.
A study examined how the essential fatty acids EPA and DHA affected SHBG levels in men 43 to 88 years of age (Nagata et al 2000). After controlling for other variables, the researchers concluded that both EPA and DHA decreased levels of SHBG in middle-aged and elderly men.
While adequate protein consumption is vital to maintaining muscle mass, it is also important in maintaining testosterone levels. A study examined the relationship between diet and SHBG, and found that diets low in protein in men 40-70 years old may lead to elevated SHBG levels and consequently decreased testosterone bioactivity (Longcope et al 2000).
Natural products to support sexual function:
Muira puama, Ptychopetalum olacoides, grows in the Amazon region of Brazil. It is considered an aphrodisiac and an effective treatment for impotence. It has been studied by Jacques Waynberg (Waynberg 1990), a prominent medical sexologist at the Institute of Sexology in Paris. In one of his studies, men with loss of libido received 1.5 grams/day of muira puama for 2 weeks. 62% rated the treatment as having a dynamic effect, and 52% with erectile dysfunction rated the treatment as beneficial. In another study, muira puama treatment was given to 100 men, aged 18 years or older, with impotence and/or loss of libido. A significantly Increased frequency of intercourse was reported in 66% of the men. Of the 46 men who complained of loss ofdesire, 70% reported libido intensification. The stability of erection during intercourse was restored in 55% of men, and 66% of men reported a reduction in fatigue. Other reported beneficial effects included improved sleep and morning erections.
Maca has been used among indigenous people in the Andes region for centuries. It is a reputed aphrodisiac and fertility enhancer. Peruvian researchers conducted a randomized, placebo-controlled double-blind study on a small group of men aged 21-56. Results showed that, versus placebo, maca improved subjective reports of male sexual desire. Subjects consumed either 1,500 mg or 3,000 mg of maca, or placebo, for three months. After eight weeks, improvements were noted in sexual desire among the subjects who consumed maca (Gonzales et al 2002).
L-Carnitine is an amino acid derivative that may be more active than testosterone in aging men who have sexual dysfunction and depression caused by an androgen deficiency (Cavallini G et al 2004). Both testosterone and carnitine improve sexual desire, sexual satisfaction, and nocturnal penile tumescence, but carnitine is more effective than testosterone in improving erectile function, nocturnal penile tumescence, orgasm, and general sexual well-being. L-Carnitine was also more efficacious than testosterone for treating depression (Cavallini G et al 2004).
Natural products to support prostate health
I3C protects against dangerous estrogen metabolites and subsequent prostate cancer. An adequate intake of I3C, through vegetables such as broccoli, Brussels sprouts, and cabbage, or via supplements, may be very helpful for aging men in both keeping undesirable estrogen metabolites such as 16-alphahydroxyestrone in check and decreasing their riskof prostate cancer. Studies have demonstrated that I3C increases the ratio of 2-hydroxyestrone to 16-alpha-hydroxyestrone. For men, this very well might mean a decrease in prostate cancer risk (Sepkovic et al 2001, Bradlow 2008). In a study that examined the association of prostate cancer risk with estrogen metabolism, the authors said, “results of this case-control study suggest that the estrogen metabolic pathway favoring 2-hydroxylation over 16-alpha-hydroxylation may reduce risk of clinically evident prostate cancer” (Muti et al 2002).
A bark extract from the native African cherry tree, Pygeum africanum has been used in Europe to treat BPH since 1960, and is currently the most commonly used therapeutic agent for this condition in France (Buck 2004). One theory for the anti-BPH action of pygeum involves the conversion of testosterone to dihydrotestosterone (DHT), a potent testosterone metabolite that may exacerbate BPH, via the enzyme 5-a-reductase (Wilt et al 2002). A recent study identified that N-butylbenzene-sulfonamide (NBBS) was isolated from P. africanum as a specific androgen receptor (AR) antagonist. NBBS inhibits AR- and progesterone receptor (PR)- mediated transactivation, as well as endogenous PSA expression and growth of human prostate cancer cells (Papaioannou et al 2009).
In Europe, saw palmetto (Serenoa repens) has been used extensively as a drug for reducing symptoms of (BPH). Saw palmetto has multiple mechanisms of action: inhibition of 5-alpha-reductase; inhibition of DHT binding to the androgen receptor; reduction of the inflammatory component of prostate growth (by inhibiting COX-2 and an enzyme called 5-lipoxygenase); induction of apoptosis and inhibition of prostate cell proliferation (Debruyne 2002; Goldmann et al 2001; Paubert-Braquet et al 1997; Vacherot et al 2000). Its clinical benefits for prostate enlargement include reduced nocturnal urinary urgency (Pavone et al 2010), decreased residual urine volume in the bladder (Giannakopoulos et al 2002), and less discomfort from urination symptoms (Mantovani 2010).
Testosterone and Prostate Cancer: The Myth
For more than 6 decades, the medical establishment erroneously conjectured that testosterone replacement therapy increases one’s risk of developing prostate cancer. This fear has made it standard practice for physicians to deprive hypogonadal male patients of testosterone replacement that could otherwise provide them with a world of cardiovascular, musculoskeletal, cognitive, metabolic and other health benefits, as discussed above.
Remarkably, though, it appears that, in most cases, the opposite is true—lower levels of endogenous testosterone present a greater risk of prostate cancer than higher levels (Morgentaler 2009). A review of data from the National Institutes of Health revealed that, in men of advancing age, “high testosterone levels are not associated with an increased risk of prostate cancer, nor are low testosterone levels protective against prostate cancer” (Morgentaler 2006).
A collaborative review of 18 prospective studies compared serum concentrations of androgen and estrogen in 3,886 men with prostate cancer with those in 6,438 healthy controls. The results showed no significant associations between the risk of prostate cancer and sex hormone levels (Roddam et al 2008).
In more than 500 men diagnosed with prostate cancer (followed over a mean of 8.7 years), high androgen levels were actually associated with a decreased risk of aggressive prostate disease, compared with no change in the risk of non-aggressive disease. Overall, levels of any steroid hormones (except estradiol) were not correlated with the risk of aggressive prostate cancer (Severi et al 2006).
Abraham Morgentaler, an associate clinical professor at the Harvard Medical School, in his book Testosterone for Life,convincingly makes the case for the benefits and safety of high testosterone vs. the dangers of low testosterone. He also goes back to the original 1941 Nobel Prize-winning research (Huggins et al 1941) about testosterone and shows how these data have been misinterpreted and unquestioned for over 70 years.
What You Need to Know: Optimizing Testosterone Levels in Aging Men
- Testosterone, the chief male hormone, is essential for libido and erectile function, and plays a crucial role in mood, energy, bone health, and body composition.
- Testosterone levels decline with age, usually beginning in a man’s mid-30s. Diminishing testosterone levels have been linked with disorders such as depression, fatigue, obesity and cognitive decline.
- Low testosterone in men is strongly associated with metabolic syndrome, and may be a risk factor for type 2 diabetes and cardiovascular disease.
- Restoring testosterone to youthful levels offers men a wealth of health benefits, including benefits for heart health, body composition, mood, and memory.
- Bioidentical testosterone has not been found to have adverse effects on the healthy prostate gland—in fact, it may help improve prostate symptoms in men with low-normal testosterone levels. Testosterone therapy is contraindicated in men with prostate cancer.
- Regular blood testing can help you and your physician decide if testosterone therapy is right for you. Optimizing testosterone levels requires a multi-pronged approach that includes optimal diet, proper nutrition, nutritional supplements, exercise, and bioidentical testosterone.