Prostate Cancer

 Prostate Cancer

If you're a man in your 40s or 50s, you're probably giving more than passing thought to the risk of prostate cancer. Even if you're younger, there's reason to be concerned about "male" problems.

Testicular cancer, which generally affects men under age 35, is on the rise--and sperm counts are dropping fast among men of all ages. What's going on? Many researchers have been drawing attention to male health issues, as if to balance the recent medical emphasis on breast cancer in women. Significantly, male and female reproductive diseases are not mutually exclusive, and many of their causes appear be identical. In addition, eating the right foods and avoiding environmental pollutants may protect both men and women.

Prostate Cancer

For years, prostate cancer was considered a disease of elderly men, most of whom died of other causes without ever having any symptoms of prostate cancer. The reason is that prostate cancers generally grow slowly and don't pose an immediate threat to health. In fact, cross-cultural medical studies have shown that prostate cancers occur at about the same incidence regardless of where men live. So, what has changed? For one, medicine has gotten better at diagnosing prostate cancer, largely because of a super-sensitive blood test called the PSA, for prostate specific antigen.

The American Cancer Society estimates that some 165,000 men will be diagnosed with the condition this year. But many doctors still question whether most of these men require any treatment at all.

Another change is medicine's growing concerns with invasive prostate cancer. The incidence of this deadly form prostate cancer does appear to be increasing among men in their 40s and 50s in some countries, including the United States. Unlike most prostate cancers, invasive cancer rapidly engulfs the organ and spreads throughout the body. This is the type of cancer that, a couple of years ago, killed actor Bill Bixby and musician Frank Zappa in middle age and at the peak of their careers.

Low Glutathione Increases Risk

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.

Soy Flavonoids Protective

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.

Red Meat May Contribute to Cause

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.

Environmental Pollutants

In addition to diet, researchers have also fingered "environmental" estrogens as a cause of prostate and other male reproductive cancers. These environmental estrogens--found in polychlorinated biphenyls (PCBs), plastics, and common pesticides--have already been implicated as a cause of breast cancer in women. "If pollutants are acting as estrogens, their effects may parallel those of the notorious drug diethylstilbestrol (DES)," observed John Rennie in Scientific American (Sept. 1993). DES, given to women from 1948 to 1971 to prevent miscarriage, was banned because it increased the risk of breast cancer in the daughters of these women.

As it turns out, the sons of women who took DES suffer above average incidence of reproductive disorders, including undescended testicles, penile deformities, and testicular cancer. The first indication that estrogen-like chemicals could affect men appeared in studies of wild animals. A researcher at the University of Florida discovered that DDT runoff led to elevated estrogen levels and small penises in male alligators. Other researchers reported that DDT exposure led to larger female populations of Western gulls and sterile males. Laboratory experiments have since confirmed that estrogen imitators, such as PCBs, encourage feminine characteristics in animals.

Although DDT is no longer used agriculturally in the United States, it is still widely used around the world to spray food crops, many of which are imported into this country. In addition, one of DDT's breakdown products, DDE, is still commonly found in land and water in the United States and works its way into the food supply. DDE has the same estrogen-mimicking properties as DDT. Once again, soy flavonoids and antioxidants might offer some protection. A Finnish study found that a high-soy diet was somewhat protective against precancerous tissue changes in mice given DES. Similarly, a study at the University of Cincinnati found that a soy diet protected against breast cancer triggered by an estrogen-like chemical.

Testicular Cancer and Low Sperm Counts

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.

Three Herbs for Benign Prostate Enlargement

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  (Serenoa repens), pygeum  (Pygeum africanum), and stinging nettles  (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.

Likewise, a number of respectable European medical journals have described the use of stinging nettles. For example, one study of 67 men with BPH found that supplements of this herb reduced nighttime urination. (Belaiche, P. Phytother Res, 1991; 5:267-9.) As you might expect, combinations of at least two of these herbs exert greater benefits at low doses. For example, a French study noted that a combination of stinging nettles and pygeum led to dramatic improvements in BPH in only one month. (Krzeski, T., Clinical Therapeutics, Nov.-Dec. 1993; 15:1011-20.)

 Conclusion

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 is strictly educational and not intended as medical advice. For diagnosis and treatment, consult your physician.