What is men's health?
The use of complementary and alternative medicine (CAM) for managing men’s health is increasing worldwide. A survey released in December of 2008 by the National Institutes of Health found that 33.5 percent of men use some form of complementary or alternative medicine. In North America, about 30 percent of men diagnosed with prostate disease use some form of CAM therapy.
Many dietary, phytotherapeutic, supplemental, and herbal agents have been used to prevent or treat prostate cancer, benign prostate hyperplasia, erectile dysfunction, and male infertility, but the role of CAM in managing men’s health conditions continues to be debated. If CAM is evaluated by criteria of evidence-based medicine, available data have not clearly established the efficacy of many alternative agents. Different extraction procedures, variations in the quality of raw products, and the lack of knowledge regarding mechanisms of action of active ingredients make comparisons between various products virtually impossible and lead to conflicting results in clinical trials. Nonetheless, many health care professionals believe that when used properly, CAM can be beneficial in improving men’s health.
Prostate cancer is the most common cancer diagnosed in men and the second leading cause of cancer-related deaths in men in the United States. No complementary or alternative treatments will cure prostate cancer, but several CAM alternatives may be helpful in preventing the disease. CAM therapies present valuable opportunities for prostate cancer, particularly in the watchful waiting population. A June 2010, survey revealed that more than one-third of recently diagnosed persons with prostate cancer utilize some form of CAM therapy.
Foods that protect against prostate cancer. Several types of foods have shown potential for preventing prostate cancer. Of special interest are soy and soy products. Epidemiological data show a ten- to one-hundred-times lower incidence of prostate cancer in Asia, compared with Western countries. Soy products are a traditional staple in the diets of Eastern countries, suggesting that nutrition plays an important role in prostate cancer prevention. Legumes such as soybeans are rich in a variety of phytochemicals and are rich in isoflavones such as genistein and several other anticarcinogens that inhibit the growth of prostate cancer cells.
Lycopene, a carotenoid found mainly in tomatoes and tomato-derived products, has been shown in a number of clinical studies to have protective effects against the development of prostate cancer. Lycopene is an acyclic isomer of beta-carotene, and its most important anticancer property may be its strong antioxidant activity.
Cruciferous vegetables such as cabbage, Brussels sprouts, and broccoli have been shown to possess anticancer activities, possibly because of the substances they contain, such as indole-3-carbinol, glucaric acid, and sulforaphane, and because of their high concentration of the carotenoids lutein and zeaxantin.
The role of dietary supplements. The effectiveness of selenium in preventing prostate cancer has been the subject of numerous clinical trials, and different trials have yielded conflicting results concerning this trace element’s protective efficacy. It is thought that selenium’s antioxidant properties may help repair deoxyribonucleic acid (DNA), prevent cell invasion, and stimulate the signaling of transforming growth factor beta.
The Nutritional Prevention of Cancer Trial, which studied 1,312 men with low selenium levels, found a 63 percent reduction in prostate cancer incidence in men supplemented with selenium, compared with placebo. The men showed a 49 percent lower risk of prostate cancer through a seven-plus-year follow-up period. Reaching opposite conclusions, the Selenium and Vitamin E Cancer Prevention Trial of 35,000 men concluded that selenium and vitamin E, taken alone or together, do not prevent prostate cancer.
The Alpha-Tocopherol, Beta-Carotene Cancer Prevention Trial studied the protective effects of vitamin E and beta-carotene in 29,133 male smokers age fifty to sixty-nine. In this trial, vitamin E supplementation led to a 32 percent reduction in prostate cancer incidence and a 41 percent decrease in prostate cancer deaths.
Herbal therapy. Interest has been growing in the use of herbs in preventing prostate cancer. Among these agents, the catechins in green tea have shown encouraging results. In a one-year trial, men with precancerous changes in the prostate received green tea extract providing 600 milligrams of catechins per day, or a placebo. Prostate cancer developed in 3.3 percent of the men receiving green tea extract and in 30 percent of those given a placebo.
CAM therapies have also been useful in treating benign prostatic hyperplasia (BPH), an affliction that eventually affects at least 80 percent of men after age fifty. BPH is not related to cancer and is more bothersome than dangerous. The cause is thought to be related to variations in levels of hormones such as dihydrotestosterone or estrogen (or both), causing enlargement of the prostate, which partially blocks the urethra and hinders urinary voiding.
Some nutraceuticals have produced results equal to or better than pharmaceuticals prescribed to treat BPH. Several meta-analyses suggest clinical efficacy and good tolerability for extracts from Serenoa repens (saw palmetto), Pygeum africanum (from the bark of the African plum tree), stinging nettle, and pumpkin seeds.
Saw palmetto extract, derived from the fruit of S. repens, the American dwarf palm, is the botanical best studied and most used to treat symptoms of BPH. It appears to contain substances that have activity similar to (but weaker than) 5-alpha-reductase inhibitors, which prevent conversion of testosterone to dihydrotestosterone. Some studies have found that the efficacy of S. repens extract is comparable to that of finasteride and alpha-blockers.
Extract of the bark of the African plum tree P. africanum moderately improves urinary symptoms associated with BPH. Numerous studies report that pygeum significantly reduces urinary hesitancy, frequency, nocturia, and pain with urination in men with mild to moderate symptoms.
Clinical studies have shown that pumpkin seed oil (Cucurbita pepo), in combination with saw palmetto, effectively reduces symptoms of BPH. Researchers have suggested that the zinc, free fatty acid, or plant sterol content of pumpkin seeds may account for their efficacy.
Stinging nettle root (Urtica dioica), in combination with other herbs (especially saw palmetto), is effective in relieving symptoms of BPH. Clinical studies have shown stinging nettle to be comparable to finasteride in slowing the growth of certain prostate cells. Unlike finasteride, however, the herb does not decrease prostate size.
The inability of men to achieve or maintain an erection sufficient for satisfactory sexual function can have considerable impact on interpersonal relationships and quality of life. According to Douglas MacKay, writing in Alternative Medicine Review, erectile dysfunction (ED) affects 50 percent of men forty to seventy years of age in the United States; by extrapolation, about thirty million men in the United States are affected. While prescription drugs have proven valuable in managing ED, they are not without limitations.
Over the centuries, many products have been touted as enhancing male vigor and libido. While the effectiveness of many of these substances cannot be adequately confirmed, arginine, yohimbine, Panax ginseng, and Ginkgo biloba all provide some degree of evidence that they are helpful for treating ED.
Nitric oxide (NO) is intimately related to penile erections. When a man becomes aroused, NO secretion begins in the blood vessels that lead into the penis, allowing the vessels to relax and widen to allow an increased flow of blood to enter the penis and harden it. NO levels decline as men age, resulting in ED. L-arginine, an amino acid found in muscle and cell tissues, is the biological precursor of NO. The formation of NO depends on sufficient levels of L-arginine in the body. L-arginine supplementation is particularly effective for treating men with abnormal NO metabolism, and most clinical trials have shown positive treatment results, often doubling levels of vascular NO.
Derived from the bark of an African evergreen tree (Corynanthe yohimbe or Pausinystalia yohimbe), yohimbine (also known as yohimbe) is regulated as a drug in some countries, where it is pharmacologically classified as an alpha-2-adrenergic receptor antagonist. As such, it blocks brain receptors involved in releasing norepinephrine in the genitals. Norepinephrine is the principal neurotransmitter involved in the vascular smooth muscle contraction that reduces penile blood flow, ending an erection. Therefore, blocking norepinephrine receptors helps prolong tumescence. Yohimbine increases the amount of blood that is allowed to flow into the penis and prevents it from flowing out.
For more than two millennia, P. ginseng has been used by Chinese healers for its restorative properties. Modern scientists have identified active constituents, including triterpene saponin glycosides known as ginsenosides, which may be responsible for some of ginseng’s antioxidant and health-preserving properties. Ginsenosides have been shown to increase the release of NO, and preliminary studies suggest that this is ginseng’s primary mechanism of action, resulting in improved penile hemodynamics.
The herb Ginkgo biloba also has vasodilating properties. It is used in many alternative herbal supplements to help increase blood flow to the genitals. Recent evidence supports indications that Ginkgo biloba extract is effective in the treatment of ED caused by the lack of blood flow to the genitals. It enhances blood circulation and appears to help ED by increasing blood flow to the penis. It can also relax the muscles and assist with penis blood flow.
Reports show that about 6 percent of adult males are believed to be infertile. Male infertility is usually associated with a decrease in the number, quality, or motility (power of movement) of sperm. Taken together, low sperm count in the semen, decreased sperm motility, and abnormal shape of the sperm are responsible for infertility in about 40 percent of men.
Excessive reactive free radicals can be very damaging to sperm. Elements in the sperm cell membrane are highly susceptible to oxidative damage. Several antioxidant supplements that regulate the effects of oxidative stress, such as vitamin C, vitamin E, glutathione, selenium, and coenzyme Q10 (CoQ10), have proven to be effective in treating this cause of male infertility.
The effects of oxidative DNA damage and the role of dietary ascorbic acid (vitamin C) in preventing this damage have encouraged examination of these factors in relation to human sperm DNA. One study showed that dietary ascorbic acid protects human sperm from oxidative DNA damage that could affect sperm quality and increase the risk of genetic defects. Another study found that daily supplementation with 200 to 1,000 milligrams of vitamin C increased the fertility of men with a condition called agglutination, in which sperm stick together.
Vitamin E supplementation has been shown to enhance fertility in men, most probably by decreasing free-radical damage to sperm cells. In another study, men with low fertilization rates were given 200 IU (international units) of vitamin E daily. After one month of supplementation, fertilization rates increased significantly, and the amount of oxidative stress on sperm cells decreased.
Glutathione and selenium are vital to the antioxidant defenses of sperm and have shown positive effects on sperm motility. Deficiencies in either of these substances can lead to defective sperm motility. In a clinical study of twenty infertile men, glutathione demonstrated a statistically significant improvement in sperm motility. Another study reported that fertile males had significantly higher selenium levels in their seminal fluid than infertile men.
Zinc deficiency is associated with decreased testosterone levels and reduced sperm count. An adequate amount of zinc ensures proper sperm production and motility. Several studies have found supplemental zinc to be helpful in treating cases of low sperm count or of decreased testosterone levels.
The amino acid L-arginine is a biochemical precursor of substances that are thought to be essential to sperm production and motility. L-arginine is also essential for the production of testosterone, the predominant hormone necessary for healthy sperm production. In one study, 74 percent of men with low sperm count experienced significant improvement in sperm count and motility after taking 4 grams of L-arginine per day for three months.
Carnitine, derived from an amino acid, contributes directly to sperm motility and may be involved in the successful maturation of sperm. This is especially important because sperm tend to accumulate carnitine while in the epididymis. Low levels of carnitine lead to potential alterations in sperm motility. One study found a direct correlation between semen carnitine content and sperm motility.
CoQ10 is concentrated in the mitochondria of sperm cells, where it is involved in energy production. It also functions as an antioxidant, preventing lipid peroxidation of sperm membranes. In one study, 10 milligrams per day of an analog of CoQ10 was given to infertile men, resulting in increases in sperm count and motility.
National Cancer Institute. Complementary and Alternative Medicine. http://www.cancer.gov/cancertopics/cam.
National Center for Complementary and Alternative Medicine. http://nccam.nih.gov.
Trivieri, Larry, Jr., and John W. Anderson. eds. Alternative Medicine: The Definitive Guide. 2d ed. Berkeley, Calif.: InnoVision Health Media, 2002.