Drinking an eight-ounce glass of pomegranate juice dailyincreased by nearly four times the period during which PSA levels in mentreated for prostate cancer remained stable, a three‑year UCLA study hasfound.
The study involved 50 men who had undergone surgery orradiation but quickly experienced increases in prostate-specific antigen orPSA, a biomarker that indicates the presence of cancer. UCLA researchersmeasured "doubling time," how long it takes for PSA levels to double, a signalthat the cancer is progressing, said Dr. Allan Pantuck,an associate professor of urology, a
Doubling time is crucial in prostate cancer, Pantuck said, because patients who have short doublingtimes are more likely to die from their cancer. The average doubling time isabout 15 months. In the UCLA study, Pantuck and histeam observed increases in doubling times from 15 months to 54 months, analmost four-fold increase.
"That's a big increase. I was surprised when I saw such animprovement in PSA numbers," Pantuck said. "In oldermen 65 to 70 who have been treated for prostatecancer, we can give them pomegranate juice and it may be possible for them tooutlive their risk of dying from their cancer. We're hoping we may be able toprevent or delay the need for other therapies usually used in this populationsuch as hormone treatment or chemotherapy, both of which bring with themharmful side effects."
The study appears in the July 1 issue of Clinical CancerResearch, the peer-reviewed journal of the American Association of CancerResearch.
"This is not a cure, but we may be able to change the wayprostate cancer grows," Pantuck said. "We don't knowyet the specific factors behind this response — that's our next step in thisresearch. We want to find out what cell signaling pathways might be affected,what is happening to keep PSA levels stable."
Pomegranate juice is known to have anti-inflammatory effectsand high levels of antioxidants, which are believed to protect the body fromfree-radical damage. It also contains polyphenols,natural antioxidant compounds found in green tea, as well as isoflavones commonly found in soy, and ellagicacid, which is believed to play a role in cancer cell death.
"There are many substances in pomegranate juice that may beprompting this response," Pantuck said. "We don'tknow if it's one magic bullet or the combination of everything we know is inthis juice. My guess is that it's probably a combination of elements, ratherthan a single component."
The levels of PSAin men immediately following treatment should be undetectable, Pantuck said. If PSA can be detected, it's an indication ofan aggressive cancer that is likely to progress. The men in Pantuck'sstudy all had detectable PSA following treatment. Of the 50 menenrolled, more than 80 percent experienced improvement in doubling times.
Conventional treatment for men with recurrent prostatecancer includes hormonal therapy, a chemical castration that removestestosterone from the system. Men treated with hormonal therapy can experiencehot flashes, osteoporosis, fatigue, depression, muscle wasting, loss of libidoand erectile dysfunction. If drinking pomegranate juice can delay or preventthe need for hormonal therapy, patients would experience a better quality oflife for a longer time, Pantuck said.
The patients in Pantuck's studyexperienced no side effects and none of the participants had cancers thatmetastasized during the study.
Pantuck, along with UCLAcolleagues including Dr. Arie Belldegrun,professor and chief of urologic oncology, and Dr. David Heber, professor anddirector of the Center for Human Nutrition, first began research on the effectsof pomegranate juice on prostate cancer about six years ago, conducting preclinicalresearch in cell cultures and in animals. Those studies showed pomegranatejuice slowed the growth of prostate cancer, Pantucksaid.
The data was impressive enough to test pomegranate juice inclinical trials, Pantuck said. To confirm their findings,a larger Phase III study, headed up by UCLA, will be conducted at 10 centersacross the county. UCLA is the only
Pantuck said he has men on thestudy more than three years out who are not being treated for prostate cancerother than drinking pomegranate juice and their PSA levels continue to besuppressed.
"The juice seems to be working," he said.
The study, performed at the
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