January 17, 2008
Veggie lovers could fare better in cancer fight
New and better information is coming to light every day about ways to prevent this common disease. Since doctors are getting better at catching it early, fewer men are dying of prostate cancer. But one in six men will still develop the disease in their lifetime.
Eat your Veggies, Drink Tea
Luckily, if you are at risk, there are things you can do. Prevention may be as simple as eating better, exercising more and taking a few key supplements. Many of these remedies, which cut inflammation, may also help men struggling with a benign enlarged prostate.
For example, eating a lot of red meat, processed foods, alcohol, sugar and high-fat dairy products can lead to inflammation in the prostate gland (and other parts of the body).
"It's best to have an overall healthy lifestyle," said dietician Dee Sandquist, a spokesperson for the American Dietetic Association (ADA). "You need to eat a balance of foods in moderate amounts."
Processed meats and high-fat dairy have more chemical residues, which also may be related to cancer risk. Instead, Sandquist suggests, eat lower on the food chain. Add more grains and legumes. Go vegetarian a couple of times per week.
One of the most promising natural compounds for prostate cancer prevention is lycopene, Sandquist suggested. You can find it in cooked tomatoes, watermelon and pink grapefruit. Sandquist recommends shooting for two to four servings of lycopene-rich foods per week. Since the body needs a little fat to absorb lycopene, have some olive oil with your pizza or spaghetti sauce.
Green tea can help, too. It's full of antioxidants that appear to fight cancer. In particular, studies show, it has a lot of promise for preventing prostate cancer cells from growing into a threat.
"Green tea leads damaged cells or cancer cells to commit suicide," said University of Wisconsin Cancer Center researcher Dr. Hasan Mukhtar.
He points to several epidemiological studies that show people who drink two to four cups of green tea per day have a lower incidence of prostate cancer (men in Asian countries, for example).
A 2005 study by Mukhtar showed pomegranate juice (the equivalent of two fruits per day) has anti-inflammatory effects that may also help with benign swelling of the prostate and cancer prevention.
Cruciferous vegetables -- such as broccoli, cauliflower, radish, turnip, cabbage and brussels sprouts -- also have cancer-busting qualities, studies show. Soy may help, but since it contains natural plant estrogens -- and prostate cancer is tied to hormones -- more study needs to be done. All of these foods should be part of a varied diet, Sandquist said. "We get the most health benefits from the overall variety," she said. "There's a synergy when these foods work together in the body. No one food has all the nutrients we need."
Does Selenium + Vitamin E = Prevention?
Meanwhile, a Phase III clinical trial of 35,000 men sponsored by the National Cancer Institute (NCI) is underway. Scientists want to know if a mix of selenium and vitamin E prevents prostate cancer. Doses used in the study include 400 milligrams per day of vitamin E and 200 micrograms per day of selenium (selenomethionine, not the yeast kind). Some of the subjects will take a placebo. Results for this longterm study, known as SELECT, will be released in 2012.
Researchers started the SELECT trial after previous smaller studies revealed benefits -- almost by accident. One study (which was actually looking at lung cancer) found men who took vitamin E had 30 percent lower incidence of prostate cancer. Another study (originally aimed at skin cancer) showed a 50 percent decrease in prostate cancer in men who took selenium.
"These are interesting agents that deserve study," said Dr. Howard L. Parnes, chief of the cancer prevention division of NCI's Prostate and Urologic Cancer Research Group. "They're both antioxidants, but that may not be how they work. They might interrupt the process in other ways."
Zyflamend Shows Promise
Another promising supplement is Zyflamend, a cluster of anti-inflammatory herbs such as tumeric and ginger, for sale by New Chapter (www.new-chapter.com) in most health food stores. Dr. Aaron Katz, director of Columbia University's Center for Holistic Urology, discovered Zyflamend when many of his patients said they were trying it for prostate problems. His initial research showed the mix of herbs in Zyflamend could stop cancer cells from growing.
"To date, 91 percent of the patients have not converted to cancer," Katz said.
He estimates 40 percent would have developed prostate cancer if they did not take Zyflamend. The men in the study took the compound three times a day, Katz said.
Mixed Results for Proscar
The only scientifically proven way to reduce the odds of prostate cancer is the conventional drug finasteride (Proscar). It's currently approved by the FDA to treat benign prostatic hyperplasia (BPH), or enlarged prostate and male-pattern baldness.
A recent NCI clinical trial showed finasteride reduced the relative risk of prostate cancer by 25 percent. But research also showed the men who took finasteride had a 1.3 percent higher risk of having high-grade prostate cancer -- the kind that is more deadly. More studies are underway that may explain the high-grade cancer risk, Parnes said. Studies of a similar drug, dutasteride, may offer additional hope.
Back to Basics
For now, making lifestyle changes and maintaining a healthy diet may be the most effective ways to prevent prostate cancer, experts say. "Obesity is actually an inflammatory state, so being physically active is incredibly important," Parnes said. "It's all about the balance between how much we eat and how much exercise we get."
In other words, get off the couch. And eat your vegetables. Especially the broccoli and tomatoes.
Melissa Knopper is a freelance writer specializing in health and science issues.