Lifestyle Management of Prostate Cancer

A recent paper published in Journal of Urology and based on work conducted at University of California, San Francisco, presents the first controlled study showing that intensive changes in diet and lifestyle could affect the progression of slow-growing prostate cancer. A group of 93 men, averaging 66 years of age, and with prostate cancer verified by biopsy, elected to not undergo conventional treatment (such as radiation, surgery or androgen deprivation therapy). This approach to managing slow-growing prostate cancer is also known as watchful waiting.

Risk factors identified for prostate cancer include: age – the disease is rare in men younger than 45; family history; race – it’s more common in African Americans (incidence and mortality trends can be found here); presence of high-grade neoplastic cells detectable under a microscope (requires a biopsy to confirm this); and diet – a diet high in animal fats or meat might pose an increased risk; a diet high in fruits and vegetables may be associated with a lower risk. Other factors that appear to be less important include benign prostatic hyperplasia, obesity, smoking, a sexually transmitted virus and lack of exercise. A vasectomy does not appear to be a significant risk factor. High levels of testosterone is another risk factor that is being studied.

Dietary factors that may be important in prevention include lycopene, a plant-derived carotenoid responsible for the red color in tomatoes and tomato-based foods, selenium and Vitamin E.

While these findings have created a little flurry of stories in the news, it seems that this work has been ongoing for some years now. A preliminary report was published in this research compilation on prostate cancer in Urology (April 2001, Vol. 57, Issue 4, Supplement 1, New Clinical Trial Strategies for Prostate Cancer Prevention).

The experimental group participants were placed on a vegan diet, and participated in moderate aerobic exercise, yoga/meditation, and a weekly support group session. The diet consisting primarily of fruits, vegetables, whole grains, and legumes supplemented with soy, vitamins and minerals. In addition to not having to undergo treatment for their prostate cancers, the participants in the experimental group also reported improvements in their quality of life.

The outcome of the study was that after one year, prostate specific antigen (PSA) levels decreased 4% in the experimental group but increased 6% in the control group. None of the experimental group patients, but 6 control patients, underwent conventional treatment due to an increase in PSA levels and/or detected progression of disease. Serum from the experimental group individuals inhibited the growth of LNCaP cells (a human prostate tumor cell line) 8-fold more than the control group. The conclusion from this study is that intensive lifestyle changes may affect the progression of early, low grade prostate cancer, warranting further studies and longer term followup.

Not everyone apparently is convinced this approach has merit. The Detroit Free Press tells us:

However, urologists not associated with the research said the length of the study was too short, the number of men too few and the outcome measures too imprecise to make definitive conclusions about the benefits of the intervention.

In addition, maintaining the strict diet used in the study would be very difficult for many men, urologists said.

"I don't know if draconian is the word," said William See, chairman of the urology department at the Medical College of Wisconsin. But "the ability of the average Midwesterner to tolerate that kind of diet is questionable."

I suppose the detractors have some points. Studies of larger groups of men, followed for longer periods of time should be performed to determine how to incorporate these findings into clinical practice; however, the authors did say that further study should be performed. There is some cause for concern in the implication that a doctor can’t convince the average Midwesterner to go vegan, even if it means preserving his life. I guess Skyline Chili and Bob Evans are powerfully habit-forming. I have difficulty appreciating the attraction, but then again I’m a transplanted Midwesterner. Have they tried motivational interviewing with their prostate cancer patients? You can learn something new all the time when you blog – MI now being something I’m familiar with thanks to The Rest of The Story.

I wonder if part of the problem with the critics is that the lead investigator is Dean Ornish, who is a strong proponent of preventive medicine through managing lifestyle factors (more on Dr. Ornish can be found here). He is somewhat lined up with the “alternative medicine” crowd. Also, I guess that watchful waiting and intensive lifestyle changes aren’t as certain or as “take-charge” as burning out the cancer cells with radiation, starving them with hormonal treatment or cutting them out with surgery. If I found myself as a prostate cancer patient, I’d be giving careful thought to the side effects from conventional treatment, along with the rate of growth of the tumor, in making treatment decisions.

A good summary of the lifestyle changes that can keep prostate cancer at bay, which gets to the point in fewer words than NCI, can be found here. Consumer’s note: LEF is a proponent of nutritional supplements, so they will tend to point you to the pills. But as long as you keep in mind that proper food choices are superior to supps to achieve optimal nutrition, the health and nutritional information appears sound and well documented, and warrants a look.

The last part of this story is the possible collateral environmental health benefits from diet and lifestyle changes. For example, the largest contribution to dietary exposure to dioxin-like compounds (dioxins, furans and co-planar PCBs) is from animal products (meat, particularly beef and animals fats including those used in processed foods). The very limited evidence available suggests that lower dietary intake of meat and animal fat also reduces exposure to dioxin-like compounds, although the authors caution that a long time may be needed to see any reductions because of the long half-lives of these compounds. It’s an area that requires wider study, however the Institute of Medicine seems sufficiently persuaded that they wrote an entire book on the topic of reducing dioxin exposure through the human foodchain.