Prostate cancer is the most common cancer to afflict American men. In fact, approximately 10 years ago, 1 in 10 men had a lifetime risk of developing prostate cancer. Today 1 in 6 men will be diagnosed over a lifetime. Due to the fact that American (and European) men are much more likely to die from prostate cancer than Asian men, the Western diet seems to be a risk factor. While the link between diet and prostate cancer remains somewhat elusive, there are specific dietary factors tied to a reduced risk of developing this disease.
Tomatoes and Lycopene
Lycopene is one of the carotenoids (beta-carotene being the most well-known), a group of disease-fighting phytochemicals (plant compounds) that act as powerful antioxidants. Lycopene protects prostate cells against cancerous mutations (changes). There is a significantly lower incidence of prostate cancer in men who consume the most dietary lycopene. Tomotoes, especially canned and processed (tomato puree, tomato paste and sauce) are lycopene-rich.
In the mid-1990s, Harvard researchers reported that men who consumed 10 servings per week of foods made with tomato sauce had a 35 percent lower risk of developing prostate cancer than those who consumed fewer than 1.5 servings per week. Other foods that are particularly high in lycopene are guavas, watermelon, carrots and papayas.
Green Tea
One of the reasons that Asian men have significantly lower rates of prostate cancer could be the fact that they consume a great deal of green tea. The tea plant is naturally high in a group of antioxidants known as catechins. Green tea offers more catechins than black tea because its production involves less processing and fermentation. One cup of green tea provides 142 mg of catechins.
Several studies have shown a beneficial effect of high catechin intake and lower rates of prostate cancer. In a study involving 50,000 Japanese men, the risk of developing advanced prostate cancer was 50 percent lower in those who consumed five or more cups of green tea daily (more than 600 mg catechins) than those who drank less than one cup daily (less than 150 mg catechins).
Other Plant Foods
Some research has shown that men who consume the most dietary fiber are at the lowest risk for developing prostate cancer. In fact, there is a link between dietary fiber and many cancers. Foods rich in dietary fiber include beans, dried fruits, vegetables such as broccoli, whole grain breads and cereals, and whole, unpeeled fruits, such as apples and pears.
Some research suggests that soy products may be protective against prostate cancer but further investigation is needed. In one cohort study that followed 82,000 men in Hawaii and Los Angeles, those who ate the most soy foods had the lowest risk of prostate cancer but another research study, focused specifically on soy isoflavones, did not show a significant difference.
A vegetable-rich diet appears to offer some protection against the development of prostate cancer. Men who consume the most vegetables (quantity), in the greatest variety (type), appear to develop less prostate cancer (over 6 servings daily versus less than 4). The best advice is to consume a wide variety of colorful vegetables daily.
References
- Journal of the National Cancer Institute; Intake of carotenoids and retinol in relation to risk of prostate cancer; E Giovannucci, A Ascherio, EB Rimm, et al.; Dec 1995
- American Journal of Epidemiology; Green tea consumption and prostate cancer risk in Japanese men: a prospective study; N Kurahashi, S Sasazuki, M Iwasaki, et al.; July 2008
- International Journal of Cancer; Legume and isoflavone intake and prostate cancer risk: The Multiethnic Cohort Study; SY Park, SP Murphy, LR Wilkens, et al.; June 2008
