Walnuts, Broccoli and Pomegranates Cut Risk of Prostate Cancer
Prostate cancer represents one of the most significant health threats to American men. According to the American Cancer Society, one in six men in the U.S. will develop the cancer, and one in 35 men will die of the disease.
The good news is that prostate cancer often responds favorably to positive lifestyle changes, especially changes in diet.
The results of a recent study at UC Davis and the U.S. Department of Agriculture demonstrated that consumption of walnuts can slow the progression of prostate tumors. Walnuts are rich in beneficial omega-3 fatty acids, antioxidants and other cancer-fighting plant nutrients known as polyphenols.
For the study, the researchers fed a diet with whole walnuts to mice that had been genetically programmed to develop prostate cancer. After 18 weeks, tumor growth was reduced by as much as 40 percent in mice consuming the human equivalent of 2.4 ounces of walnuts daily compared to mice fed nut-free rations.
Human studies show that eating at least one serving of broccoli each week can reduce the risk of developing prostate cancer in the first place. In men who have the disease, regular consumption of broccoli can help prevent the cancer from spreading.
According to a scientific review published last year in the Journal of Human Nutrition and Dietetics, diets rich in plant foods are beneficial in the prevention and treatment of prostate cancer. Regular consumption of tomatoes and cruciferous vegetables, such as broccoli, kale and cauliflower, was linked to a significantly lower risk of developing the disease and a slowing of its progression.
The results of a study conducted at the University of Pittsburgh suggest that the polyphenols found in cruciferous vegetables act by impairing the growth of prostate cancer cells. These powerful plant compounds also inhibit the formation of new blood vessels that feed the tumors and allow the cancer to spread.
Regular consumption of broccoli offers excellent cancer protection, but the protection provided by a combination of broccoli and tomatoes may be even better. Researchers at the University of Illinois found that prostate tumors shrank more in animals fed extracts of both broccoli and tomatoes than in those fed either substance alone.
While raw broccoli appears to offer greater cancer protection than cooked broccoli, heated tomato products may be more beneficial than raw tomatoes. Slicing, dicing and heating tomatoes makes their primary cancer-fighting compound, lycopene, easier for the body to absorb.
Numerous studies have proven the benefits of lycopene in the prevention and treatment of prostate cancer. In a six-year trial involving nearly 48,000 male health professionals, Harvard researchers found that those who consumed tomato products more than twice weekly lowered their risk of developing prostate cancer by as much as 34 percent.
At the Karmanos Cancer Institute, researchers found that when men with prostate tumors were treated with lycopene, the cancer was significantly less likely to grow or spread throughout the body. Treatment with lycopene from tomatoes also lowered blood levels of prostate specific antigen (PSA), a biomarker used to evaluate the progression of prostate cancer.
Like tomatoes, pomegranate juice has proven benefits in the prevention and treatment of prostate cancer. The pomegranate, a fruit native to the Middle East, is rich in antioxidants and polyphenols with powerful anticancer properties.
In a three-year UCLA study, researchers evaluated the effects of daily consumption of pomegranate juice in 50 men with prostate cancer. The men had undergone treatment with surgery or radiation, but quickly experienced ominous rises in PSA levels.
The researchers measured the “doubling time,” or the length of time in which PSA levels double, a signal that the cancer is progressing. Doubling time is critically important in prostate cancer, because men who exhibit short doubling times in PSA are more likely to die from the disease.
The men in the study who drank an 8 ounce glass of pomegranate juice daily experienced a nearly fourfold increase in the period during which PSA levels remained stable, rather than rising. Compared to an average doubling time of roughly 15 months, the men treated with pomegranate juice exhibited much more favorable doubling times of 54 months.
A diet rich in pomegranate juice, walnuts, broccoli and tomatoes can’t be considered a cure for prostate cancer, but it might help prevent a recurrence in men with a history of the disease. For men who have never had the condition, regular consumption of these and other plant foods could dramatically reduce the risk of getting prostate cancer in the first place.