Pomegranate is a rich source of antioxidants, and has been linked to improving heart health, joint health, dental health, and supporting a healthy immune system.

A growing body of research now suggests that the fruit also protects against prostate cancer. A new study indicates that the anti-prostate cancer effects of pomegranate and its extracts may be related to stopping an enzyme in the liver which processes environmental carcinogens.

The main antioxidants found in pomegranate are ellagitannin compounds like punicalagins and punicalins, which account for about half of the fruit's antioxidant ability, and these are reportedly behind its proposed health benefits.

The new study explains how the constituents of the fruit may boost prostate health.

They report that pomegranate's ellagitannin compounds may inhibit the activity of an enzyme known to be highly expressed in various human cancers, but not in normal tissues, and a known target in the prevention of prostate cancer.

"Our study has asserted a previously unknown mechanism of action of pomegranate juice constituents, which could potentially contribute to prostate cancer chemoprevention,"

"We proved that systemically available metabolites of pomegranate juice are effective inhibitors of CYP1B1 enzyme activity/expression and could lower the incidence of prostate cancer initiation and sustenance."

"It is also well-known that prostate cancer typically possesses long latency periods and develops in older men; therefore, cancer chemoprevention by dietary supplement-based intervention is a desirable form of chemotherapy,"

"Pomegranate juice consumption, thus, may be of considerable advantage in prostate cancer chemoprevention, not only in patients with a genetic predisposition toward prostate cancer but also in patients undergoing cancer therapy."

Research paper details:

S.G. Kasimsetty, D. Bialonska, M.K. Reddy, C. Thornton, K.L. Willett, D. Ferreira. Effects of pomegranate Chemical Constituents/Intestinal Microbial Metabolites on CYP1B1 in 22Rv1 prostate cancer Cells. Journal of Agricultural and Food Chemistry, published online ahead of print.

Pomegranates are also rich in vitamins B and C, and pomegranate juice has been found to contain three times the amount of polyphenols than are found in green tea. Physical Activity Cuts prostate cancer Risk

A further study published in the online British Journal of Cancer, suggests that high levels of physical activity may also help reduce risk of prostate cancer.

After analyzing data over 10 years, researchers found an inverse association between lifetime physical activity, such as walking or bicycling, and risk of prostate cancer.

For every 30 minutes per day increment of lifetime walking or bicycling in the range of 30 to 120 minutes per day, the risk for total prostate cancer decreased by 7 percent; for localized prostate cancer by 8 percent and for advanced prostate cancer by 12 percent. The researchers concluded:

"Our results suggest that not sitting for most of the time during work or occupational activity and walking or bicycling more than 30 min per day during adult life is associated with reduced incidence of prostate cancer."

Research paper details:

Orsini N, Bellocco R, Bottai M, Pagano M, Andersson SO, Johansson JE, Giovannucci E, Wolk A. A prospective study of lifetime physical activity and prostate cancer incidence and mortality. Br J cancer. 2009 Oct 27.