Health Wellness

Nutrition & Prostate Cancer:Top 10 Risk Reducers

by Dr. Andrew Weil

Men can greatly lower their odds of prostate cancer by adjusting what is—and isn’t—on their dinner plates and in their drinking glasses. For instance, diets high in red meat and dairy have been linked to a higher risk of the disease, and preliminary research suggests the omega-6 fatty acids in corn and other vegetable oils may spur prostate cancer growth, probably by increasing inflammation. Meanwhile, I’ve seen mounting evidence that other foods and beverages described here have protective effects.

Pot of cooked tomatoesCooked tomatoes. Eating tomato sauce at least twice a week can lower the risk of prostate cancer by 33 percent, according to data from more than 47,000 men in the Health Professionals Follow-Up Study (Journal of the National Cancer Institute, March 6, 2002). Tomatoes are rich in lycopene, a carotenoid pigment that acts as a powerful antioxidant and helps to ward off the malignancy. My advice: Lycopene is more readily available from cooked tomatoes than from raw ones and needs some fat to be absorbed, so a good choice is tomato sauce made with olive oil. Watermelon and pink grapefruit also have lycopene, but in smaller amounts.



vegi imageCruciferous vegetables. Other findings from the Health Professionals Follow-Up Study concluded that men who ate at least five servings a week of cruciferous veggies were 10 to 20 percent less likely to develop prostate cancer (Cancer Epidemiology, Biomarkers & Prevention, December 2003). Crucifers—including broccoli, kale, Brussels sprouts, cabbage, collards, cauliflower and bok choy—are packed with cancer-protective phytonutrients like indoles and sulforaphane. These vegetables are also a source of vegetable fiber, which has been linked with a lower risk of prostate cancer. My advice: Eat cruciferous vegetables most days of the week.

soybean plantSoy foods. A recent analysis of eight studies concluded that regular consumption of soy foods was associated with a 30 percent lower risk of prostate cancer (International Journal of Cancer, November 20, 2005). Plus, eating a soy-rich diet may improve prostate-specific antigen (PSA) levels, a marker for prostate cancer, in men with the disease. Soy is high in isoflavones, phytoestrogens that may protect against prostate and breast cancer by helping normalize hormone levels. One theory is that phytoestrogens attach to estrogen receptors but activate them only weakly. My advice: Eat one or two servings a day of whole soy foods like tofu, tempeh, soy milk, edamame and soy nuts. Soy supplements, including soy protein powder, may not offer the same benefits.

Grilling fishOily fish. Men with the highest intakes of the omega-3 fatty acids EPA and DHA from oily fish were 26 percent less likely to develop advanced prostate cancer than men with the lowest intakes, according to an analysis of data from the Health Professionals Follow-Up Study (American Journal of Clinical Nutrition, July 2004). EPA and DHA may cut cancer risk by inhibiting inflammation, and lab studies suggest they can block the spread of prostate cancer to other parts of the body. My advice: Eat oily fish such as wild Alaskan salmon, sardines, herring or black cod at least twice a week, or take a fish-oil supplement at a dose of 1 to 2 grams a day.

 

flaxseedsFlaxseed. These tiny seeds are the richest food source of lignans, phytoestrogens thought to protect against hormone-driven cancers such as prostate, breast and ovarian. Flax is also a good source of omega-3s and fiber. My advice: Eat 2 tablespoons of freshly ground flaxseed a day; sprinkle it on cereals, salads and vegetables. Avoid supplementing with flaxseed oil, which often lacks the beneficial lignans and fiber and also goes rancid quickly.

 


Chili peppersChili peppers
. Capsaicin, the compound in chili peppers that gives them their heat, may also kill prostate cancer cells, says preliminary research. Capsaicin caused some 80 percent of human prostate cancer cells growing in mice to die, and prostate cancer tumors in mice fed capsaicin were about one-fifth the size of those in untreated mice. These findings have yet to be confirmed in humans, but researchers believe capsaicin may work by blocking a chemical that promotes cancer cell growth (Cancer Research, March 15, 2006). My advice: You may want to spice up meals with jalapeños, habaneros and other hot peppers.


Green tea. This beverage is high in antioxidant compounds called polyphenols that may be protective against a range of cancers. In a clinical trial of 62 men with precancerous prostate cells, those who supplemented with 600 mg daily of polyphenols extracted from organic green tea (the equivalent of drinking 15 cups) for a year were less likely to develop prostate cancer than men who took a placebo (Cancer Research, January 15, 2006). My advice: Men at an elevated risk for prostate cancer (like African Americans and those with a strong family history of the disease) might consider taking a green-tea extract, but otherwise, I suggest men drink at least two cups of green tea daily (4 cups may be better).

Red Wine and Prostate Cancer

Red wine. In a study of 1,456 middle-aged men, those who drank four or more 4-ounce glasses of red wine a week had a 48 percent lower risk of prostate cancer than non-drinkers (International Journal of Cancer, January 1, 2005). The antioxidant resveratrol, abundant in the skins of red grapes, may be responsible for wine’s protective effects. My advice: If you’re a teetotaler, there’s no need to change. But if you do drink, favor red wine and limit your intake to a glass or two a day.

Pomegranate juice. A recent study of 46 men with rising PSA levels after surgery or radiation for prostate cancer suggests that drinking two cups of pomegranate juice daily may slow the progression of the disease (Clinical Cancer Research, July 1, 2006). These findings have prompted a larger clinical trial at 10 medical centers. Pomegranate juice is very high in polyphenols and contains isoflavones found in soy and ellagic acid found in berries, another compound with cancer-preventive properties. My advice: Consider drinking a daily glass of pomegranate juice if you’re at high risk.

Supplements. Vitamins D and E and selenium have shown promise for reducing prostate cancer risk, but it’s difficult to get adequate amounts of these nutrients from diet alone. My advice: Take daily supplements of vitamin D3 (cholecalciferol; at least 1,000 IU), vitamin E (either 400 IU of natural mixed tocopherols, or 80 mg of mixed tocopherols and tocotrienols), and selenium (200 mcg). Men at high risk may also want to take New Chapter’s Zyflamend, which contains anti-inflammatory herbs such as turmeric. A lab study found that the supplement suppressed the growth of—and helped destroy—prostate cancer cells (Nutrition and Cancer, October 2005), and a clinical trial is now under way.


The Age Connection

Your age may influence how some dietary and other lifestyle factors affect your prostate cancer risk. Harvard researchers theorize that inflammation plays a significant role in prostate cancer that occurs in older men, while hormones may be more important to causing the disease in younger men. Some key examples:
Lycopene. This pigment in tomatoes appears more protective in men over 65 than in those under 65. Lycopene helps reduce damage from inflammation.

Exercise. Moderate physical activity lowers an older man’s risk of prostate cancer, but seems to offer little or no protection in younger men. Exercise can reduce inflammation by improving insulin resistance.

Note: Natural (Organic) vegetables may be best for your health. They do not contain pesticides, growth hormones, additives or preservatives.