Today at the Prostate Cancer Foundation’s Annual Scientific Retreat, researchers will share new findings on how eating common foods such as tomatoes and fish, maintaining a healthy weight, and avoiding meats cooked at high temperatures may help prevent prostate cancer, and help men live healthier and longer after diagnosis. One in six men will be diagnosed with prostate cancer in their lifetime, and an estimated 218,890 cases will occur in The United States this year.
Since the 1980s, researchers have hypothesized that nutrition choices could be connected to prostate cancer. Today, those ideas are being substantiated by more widespread studies, in combination with newer technologies in gene research.
“There are strong indicators in our research that diet and lifestyle are very important with this particular form of cancer,” said Meir Stampfer, M.D., Professor of Epidemiology and Nutrition, Harvard School of Public Health. “When we look at men from other cultures like in Asia, the rates of prostate cancer are significantly lower than in the U.S. Yet when these same men move here, within one generation, the rates increase very rapidly. We believe there is a clear correlation to how we live and eat.”
June Chan, ScD, of the University of California San Francisco, has been studying the potential impact of fish oil and tomato extracts on the prostate gland prior to and after exposure. “What we’re trying to determine is if men with low grade prostate cancer can manage their disease with these kinds of nutritional interventions and delay or avoid the need for more aggressive treatments, all of which carry a risk of side effects that can adversely affect physical function and quality of life,” said Chan. “In combination with other studies, the potential we see for these everyday supplements or foods to help men avoid or delay treatment is promising.”
This type of approach, often deemed “active surveillance,” is a prostate cancer disease management option that monitors prostate-specific antigen (PSA) levels as well as the grade and stage of the tumor until a more aggressive treatment option may become necessary. One-quarter to one-half of all cases of diagnosed prostate cancer in the U.S. and Europe are considered candidates for this kind of approach, which researchers hope leads to better outcomes for patients with low-risk disease. One aspect of this management approach may include specific dietary modifications such as minimizing intake of red, processed or well-done meats.
Angelo De Marzo, M.D., Ph.D., along with colleague William G. Nelson M.D., Ph.D. of the Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, have been studying one of the most high profile issues around diet and prostate cancer: don’t overheat your meat. “We’ve known since the 1980s that ingesting meat cooked at very high temperatures can cause cellular mutations, some of which can lead specifically to prostate cancer. What we’ve found now in the rodent prostate is that the specific areas within the organ that develop cancer after exposure to the meat compounds also first become inflamed and develop a form of atrophy that resembles damaged areas in the human prostate that are likely a very early indicator of a problem.” According to De Marzo, if scientists can develop markers of damage and dietary exposures it may be possible for doctors to intervene before cancer ever develops in the prostate.
De Marzo also has some practical advice: “If you’re going to eat meat cooked at high temperatures, like I still enjoy, flip your hamburgers more often so the outside does not burn, marinate the meat in ingredients (such as teriyaki sauce) that don’t create a crust, precook it in the microwave, or at the least scrape off the charred material.” De Marzo also suggests replacing chicken, beef, veal or lamb with soy protein or fish, taking a page from the Asian diet where disease rates are very low. “We need to be realistic: you can help reduce your chance of developing prostate cancer without becoming a vegetarian.”
With more widespread testing for prostate cancer using the common PSA test, increasing numbers of new cases are being tracked. The resulting volume of patients, many of whom may have less virulent forms of prostate cancer, is creating a challenge for physicians determined to provide patients with the most appropriate advice – which may not always include aggressive treatment.
“Thanks to funding from the Prostate Cancer Foundation and others like the National Cancer Institute, we’re getting closer every day to developing the best protocols for thousands of men with this diagnosis,” said Stampfer. Our goal is that any man with low risk prostate cancer can make simple changes that will extend his life and that healthy men can avoid it altogether.”
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