One important clue to the cause of prostate cancer emerged in a recent comparison of prostate cancer cells and healthy ones. William Nelson, M.D., of the Johns Hopkins University School of Medicine, Baltimore, Md., discovered a genetic defect in prostate cancer cell samples from 88 of 91 men. This defect prevents the body from producing glutathione S-transferase (GST), a substance needed by the liver to detoxify harmful chemicals. The defect was not found in cells from healthy men.

"GSTs have been proposed to play a critical role in defending normal cells against...carcinogens...a possible prostate cancer prevention strategy might be the therapeutic augmentation of GST activity by using GST inducers," Nelson wrote in Proceedings of the National Academy of Sciences of the USA (Nov. 22, 1994; 91:11733-7).  This strategy for preventing prostate cancer can be put into practice without waiting for additional research. GST is dependent on glutathione, a powerful antioxidant found in food and also made by the body (from the amino acids glutamic acid, cysteine, and glycine). Vitamin C and the amino acid lysine promote the formation of glutathione and GST. Nutritional chemicals called isothiocyanates and sulforaphanes, found in broccoli, cauliflower, and brussels sprouts, also increase production of glutathione and GST.

Another group of nutrients, called (bio)flavonoids, appears to protect against invasive prostate cancer. More than 4,000 flavonoids have been identified in plants, but a particular one in soy may be the most important in terms of preventing prostate cancer.  This soy flavonoid, (Research) genistein, has a very weak estrogenic effect--so weak, in fact, it will not affect masculinity. Yet, it seems to protect against prostate cancers stimulated by male and female hormones. (In actuality, the "female" hormone estrogen is also produced in the male body, though in very small amounts.)  An international team of researchers has suggested that soy intake may account for why some men have a low incidence of invasive prostate cancer relative to others. Herman Adlercreutz, M.D., and his colleagues from Finland and Japan compared levels of several types of flavonoids in the blood of 14 healthy middle-aged Japanese and 14 Finnish men. On average, blood levels of these nutrients--including genistein--were 7 to 110 times higher among the Japanese men, compared with the Finns. Other research has shown that genistein prevents malignant angiogenesis, the development of blood vessels that promote cancer growth. It also encourages normal cellular differentiation in some types of cancer cells, such as leukemia cells.

"A life-long high concentration of isoflavonoids in (blood) plasma might explain why Japanese men have small latent carcinomas that seldom develop to clinical disease," wrote Adlercreutz, in the journal Lancet (Nov. 13, 1993; 342:1209-10).

Soy foods, such as tofu and soy milk, are excellent sources of genistein, and a person doesn't have to consume large amounts to benefit. Mark Messina, Ph.D., author of The Simple Soybean and Your Health (Avery Publishing Group, 1994), says that one serving daily--3-4 ounces of tofu, an 8-ounce glass of soy milk--is probably sufficient.

Certain types of dietary fat, such as alpha-linolenic acid, may increase your risk of invasive prostate cancer. While alpha-linolenic acid doesn't cause prostate cancer, it does seem to encourage the cancer's spread beyond the prostate.  In an analysis of several hundred cases of prostate cancer among 51,000 men, Edward Giovannucci, M.D., of the Harvard Medical School, found that men eating large amounts of meat and animal fat, high in alpha-linolenic acid, were 80 percent more likely to die from prostate cancer than those who ate meat sparingly. Also at risk were men who ate large amounts of mayonnaise, creamy salad dressings, and butter, according to Giovannucci's article in the Journal of the National Cancer Institute (Oct. 6, 1993; 85:1571-9).  In a follow-up article, published in the Journal of the National Cancer Institute (Feb. 16, 1994; 86:281-6), Giovannucci explained that men consuming meat five times a week were two to three times more likely to develop invasive prostate cancer than those who ate meat only once per week.  Other studies have reported that omega-3 fatty acids from fish oils suppress the growth of prostate cancer cells, according to an article in Nutrition and Cancer (1994; 22:1-10) by Ernst L. Wynder, M.D., director of the American Health Foundation, New York City. However, Giovannucci's own findings on the protective role of fish oils were mixed.

Testicular cancer, while relatively rare, is the most common type of cancer among men ages 15 to 35, and its worldwide incidence has increased as much as fourfold since 1940. During this same period--since the introduction of synthetic estrogens into the environment--the incidence of undescended testicles in young men has doubled and sperm counts have dropped by 50 percent. At a scientific meeting, "Estrogens in the Environment," held in January 1994 in Washington, D.C., Niels E. Skakkebaek, M.D., an endocrinologist at the University of Copenhagen, Denmark, and Richard M. Sharpe, Ph.D., of the Medical Research Council's Center for Reproductive Biology, Edinburgh, noted that many synthetic chemicals polluting the environment can imitate estrogenic hormones. One of the estrogen links comes from similarities among the sons of women treated with DES. As early as the 1970s, Skakkebaek noticed that many male patients with reproductive malformations eventually developed testicular cancer. He found that some of the abnormal, precancerous cells from children were similar to fetal cells, suggesting that something went awry while they were still in the womb. But don't blame everything on DES mothers and environmental estrogens. Fathers play an important role in promoting the health of their sons, too.

In one study, Paul A. Motchnik, Ph.D., of the University of California, Berkeley, discovered that low levels of vitamin C increase the likelihood of genetic damage to sperm. That, in turn, increases the odds of children with genetic defects and increases their cancer risk, according Motchnik's article in Proceedings of the National Academy of Sciences (Dec. 15, 1991; 88:11003-6).

Several studies have found that smoking tobacco lowers the body's levels of vitamin C. One bright spot is a study by Earl B. Dawson, Ph.D., of the University of Texas, Galveston, showing that 1,000 mg of vitamin C daily dramatically improves sperm quality. You cannot, however, expect to reverse the effects of smoking just by taking vitamin C.

Prostate enlargement, technically known as benign prostatic hyperplasia (BPH), tends to affect most men past 50. By this age, levels of the male hormone testosterone begin declining while a hormonal byproduct, dihydrotestosterone, starts increasing. The latter causes the prostate to enlarge, which then pinches the urethra and blocks the flow of urine from the bladder.  Sometimes BPH can cause painful urination. Often, it's just a nuisance or embarrassing--getting up several times during the night to urinate, never feeling like you've emptied yourself, or dribbling.

Doctors often prescribe two aggressively marketed drugs for BPH, including of terazosin HCl (Abbott Laboratories' Hytrin) or finasteride (Merck & Company's Proscar). Their side effects include dizziness, impotence, and loss of libido. For years, alternative practitioners have recommended three safe, effective, and inexpensive herbs for the treatment of BPH. They are saw palmetto  (Research) (Serenoa repens), pygeum  (Research) (Pygeum africanum), and stinging nettles  (Research) (Urtica dioica). Their value in BPH has for many years been documented in European medical journals.  Saw palmetto works the same way the drug finasteride does, but it's cheaper and appears much safer. It prevents the breakdown of testosterone to dihydrotesterone. Since the mid-1980s, at least 10 studies--including well-controlled double-blind studies--on more than 1,000 patients in Europe have confirmed the value of saw palmetto. In a recent three-month study, 88 percent of the patients treated with saw palmetto and their physicians reported improvement in urinary flow, less residual urine, and reduced prostate size. (Braeckman, J., Current Ther Res,1994; 55:776-85.)   An Italian study, published in 1991, reported that pygeum reduced urinary problems and prostate inflammation--and also increased sexual desire. (Carani, C., Archivio Italiano di Urologia, Nefrologia, Andrologia, Sept. 1991; 63:341-5.) At least a dozen other studies have been published on the benefits of pygeum in BPH.

More and more, men are willing to consider ways to actively prevent prostate and other male cancers. While no one relishes the thought of cancer, the consequences of surgery and radiation for prostate cancer can be as discouraging as the disease. Impotence and incontinence are common because surgery and radiation can damage nerves that lead to the penis and rectum. In addition, surgery kills 2 percent of men over age 75 and causes major heart and lung complications in 8 percent of the others, according to a report in the Journal of the American Medical Association (May 26, 1993; 269:2633-36).  Another reason to carefully weigh the need for prostate surgery is that, for most cases, life expectancy with treatment is practically the same as with no treatment. That's why Craig Fleming, M.D., of the Oregon Health Sciences University in Portland, pointed out in JAMA (May 26, 1993; 269:2650-58) that "watchful waiting" may be the best treatment for a localized, non-invasive form of the disease. A rational dietary plan to prevent prostate, and perhaps testicular, cancer would include abundant soy foods, fresh fish, organic produce grown without pesticides, and limited consumption of red meat. You may still not avoid prostate cancer, but you are likely to reduce your risk of the deadlier invasive form of the disease. This article originally appeared in Let's Live magazine. The information provided by Jack Challem and The Nutrition Reporter&trade newsletter is strictly educational and not intended as medical advice. For diagnosis and treatment, consult your physician.

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