According to findings published in the Journal of Urology and presented at the 104th Annual Scientific Meeting of the American Urological Association (AUA), a daily glass of pomegranate juice experienced slower doubling times of prostate specific antigen (PSA).
PSA is a marker commonly used to screen for prostate cancer and for tracking the disease after its diagnosis.
"This study suggests that pomegranate juice may effectively slow the progression of prostate cancer after unsuccessful treatment," said Christopher Amling, MD, spokesperson for the AUA.
"This finding and other ongoing research might one day reveal that pomegranate juice is an effective prostate cancer preventative agent as well."
Pomegranate, a rich source of antioxidants, has been linked to improved heart health, but a growing body of science indicates the fruit protect against prostate cancer. Studies have also reported a role in joint health by slowing cartilage loss in arthritis.
It is these antioxidants, and particularly ellagitannin compounds like punicalagins and punicalins, which accounts for about half of the fruit's antioxidant ability, that are reportedly behind the proposed health benefits.
Forty-eight participants with rising PSA after surgery or radiotherapy, and PSA levels between 0.2 and 5 ng/ml were assigned to drink 237ml (eight ounces) of pomegranate juice daily.
During 56 months of follow-up, the participants continued to experience a significant increase in PSA doubling time, from an average of 15.4 months at the start to 60 months after treatment. When the researchers compared patients who remained on the study with ex-study participants, they found that the PSA doubling time prolongation and the decline in median PSA slope were greater in the active, pomegranate-receiving participants.
The phase 2 study is being followed by a phase 3 study, which will evaluate the benefits of pomegranate juice in a placebo-controlled manner, said the researchers.
Building the science
The study follows similarly positive results from UCLA published in 2006 in the journal Clinical Cancer Research (Vol. 12, pp. 4018-4026). In that instance, 46 men were given eight ounces (227g) of pomegranate juice (Wonderful variety, equivalent to 570 mg of polyphenols) every day, and followed in three-month intervals.
The researchers found that the average doubling time increased from an average of 15 months to 54 months for the men drinking the pomegranate juice.
Over half a million men worldwide are diagnosed with prostate cancer every year, with over 200,000 deaths from the disease. The lowest incidence of the cancer is in Asia and the Far East, in particular India and China.
Source: Journal of Urology 2009, Volume 181, issue 4, Page 295“Long term follow up of phase 2 study of pomegranate juice for men with prostate cancer shows durable prolongation of PSA doubling time” Authors: A.J. Pantuck, N. Zomorodian, M. Rettig, W.J. Aronson, D. Heber, A.S. Belldegrun