Granaatappelsap effectief bij prostaatkanker.*

Uit een gedegen Amerikaans onderzoek ( een fase II studie) onder 50 mannen met prostaatkanker die behandeld waren door chirurgie en/of bestraling, blijkt dat het drinken van een groot glas granaatappelsap per dag het kankerproces zeer duidelijk doet vertragen. De normale tijd waarin bij deze mensen de PSA waarden verdubbelen ligt ongeveer op 15 maanden. Met iedere dag granaatappelsap is deze “dubbeltijd” bijna vier keer zo lang en gemiddeld 54 maanden. Het is al langer bekend dat granaatappels ontstekingsremmend werken en veel antioxidanten bevatten die het lichaam beschermen tegen vrije radicalen schade. Verder bevatten granaatappels veel bioa-actieve stoffen zoals polyfenolen die ook gevonden worden in groene thee , isoflavonen zoals die gevonden worden in soja en ellagetaninnes zoals die gevonden worden in frambozen.

Deze ellagitaninnes staan bekend om hun dodende werking op kankercellen. Gelet op de zeer goede resultaten van deze studie wordt nu al een vervolgstudie (een fase III studie) opgezet.

Pomegranate Juice Keeps PSA Levels Stable in Men Treated for Prostate Cancer

Drinking an eight ounce glass of pomegranate juice daily increased by nearly four times the period during which PSA levels in men treated for prostate cancer remained stable, a three-year UCLA study has found.

The study involved 50 men who had undergone surgery or radiation but quickly experienced increases in prostate-specific antigen or PSA, a biomarker that indicates the presence of cancer. UCLA researchers measured "doubling time," how long it takes for PSA levels to double, a signal that the cancer is progressing, said Dr. Allan Pantuck, an associate professor of urology, a Jonsson Cancer Center researcher and lead author of the study.

Doubling time is crucial in prostate cancer, Pantuck said, because patients who have short doubling times are more likely to die from their cancer. The average doubling time is about 15 months. In the UCLA study, Pantuck and his team observed increases in doubling times from 15 months to 54 months, an almost four-fold increase.

"That's a big increase. I was surprised when I saw such an improvement in PSA numbers," Pantuck said. "In older men 65 to 70 who have been treated for prostate cancer, we can give them pomegranate juice and it may be possible for them to outlive their risk of dying from their cancer. We're hoping we may be able to prevent or delay the need for other therapies usually used in this population such as hormone treatment or chemotherapy, both of which bring with them harmful side effects."

The study appears in the July 1 issue of Clinical Cancer Research, the peer-reviewed journal of the American Association of Cancer Research.

"This is not a cure, but we may be able to change the way prostate cancer grows," Pantuck said. "We don't know yet the specific factors behind this response - that's our next step in this research. 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 effects and high levels of anti-oxidants, which are believed to protect the body from free-radical damage. It also contains poly-phenols, natural antioxidant compounds found in green tea, as well as isoflavones commonly found in soy, and ellagic acid, which is believed to play a role in cancer cell death.

"There are many substances in pomegranate juice that may be prompting this response," Pantuck said. "We don't know if it's one magic bullet or the combination of everything we know is in this juice. My guess is that it's probably a combination of elements, rather than a single component."

The levels of PSA in men immediately following treatement should be undetectable, Pantuck said. If PSA can be detected, it's an indication of an aggressive cancer that is likely to progress. The men in Pantuck's study all had detectable PSA following treatment. Of the 50 men enrolled, more than 80 percent experienced improvement in doubling times.

Conventional treatment for men with recurrent prostate cancer includes hormonal therapy, a chemical castration which removes testosterone from the system. Men treated with hormonal therapy can experience hot flashes, osteoporosis, fatigue, depression, muscle wasting, loss of libido and erectile dysfunction. If drinking pomegranate juice can delay or prevent the need for hormonal therapy, patients would experience a better quality of life for a longer time, Pantuck said.

The patients in Pantuck's study experienced no side effects and none of the participants had cancers that metastasized during the study.

Pantuck, along with UCLA colleagues including Dr. Arie Belldegrun, professor and chief of urologic oncology, and Dr. David Heber, professor and director of the Center for Human Nutrition, first began research on pomegranate juice in prostate cancer about six years ago, conducting preclinical research in cell cultures and in animals. Those studies showed pomegranate juice slowed the growth of prostate cancer, Pantuck said.

The data was impressive enough to test pomegranate juice in clinical trials, Pantuck said. To confirm their findings, a larger Phase III study, headed up by UCLA, will be conducted at ten centers across the county. UCLA is the only Southern California center involved in the study. For more information on the Phase III trial, call (310) 825-5538.

Pantuck said he has men on the study more than three years out who are not being treated for prostate cancer other than drinking pomegranate juice and their PSA levels continue to be suppressed.

"The juice seems to be working," he said.

The study, performed at the Clark Urology Center, was funded by the Stewart and Lynda Resnick Trust. The Resnicks own POM Wonderful, which provided the juice from the Wonderful variety of pomegranate for the study.

UCLA's Jonsson Comprehensive Cancer Center comprises more than 240 researchers and clinicians engaged in research, prevention, detection, control, treatment and education. One of the nation's largest comprehensive cancer centers, the Jonsson center is dedicated to promoting research and translating the results into leading-edge clinical studies. In July 2005, the Jonsson Cancer Center was named the best cancer center in the western United States by U.S. News & World Report, a ranking it has held for six consecutive years.

Phase II Study of Pomegranate Juice for Men with Rising Prostate-Specific Antigen following Surgery or Radiation for Prostate Cancer

Allan J. Pantuck¹, John T. Leppert¹, Nazy Zomorodian¹, William Aronson¹, Jenny Hong¹, R. James Barnard³, Navindra Seeram², Harley Liker², Hejing Wang⁴, Robert Elashoff⁴, David Heber², Michael Aviram⁵, Louis Ignarro² and Arie Belldegrun¹

Authors' Affiliations: Departments of ¹ Urology, ² Medicine, ³ Physiologic Science, and ⁴ Biomathematics, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California and ⁵ Technion Faculty of Medicine, Rambam Medical Center, Bat-Galim, Haifa, Israel

Requests for reprints: Allan J. Pantuck, Department of Urology, David Geffen School of Medicine, University of California at Los Angeles, 66-118 Center for Health Sciences, Box 951738, Los Angeles, CA 90095-1738. Phone: 310-206-2436; Fax: 310-206-4082; E-mail: apantuck@mednet.ucla.edu.

Purpose: Phytochemicals in plants may have cancer preventive benefits through antioxidation and via gene-nutrient interactions. We sought to determine the effects of pomegranate juice (a major source of antioxidants) consumption on prostate-specific antigen (PSA) progression in men with a rising PSA following primary therapy.

Experimental Design: A phase II, Simon two-stage clinical trial for men with rising PSA after surgery or radiotherapy was conducted. Eligible patients had a detectable PSA >0.2 and <5 ng/mL and Gleason score 7. Patients were treated with 8 ounces of pomegranate juice daily (Wonderful variety, 570 mg total polyphenol gallic acid equivalents) until disease progression. Clinical end points included safety and effect on serum PSA, serum-induced proliferation and apoptosis of LNCaP cells, serum lipid peroxidation, and serum nitric oxide levels.

Results: The study was fully accrued after efficacy criteria were met. There were no serious adverse events reported and the treatment was well tolerated. Mean PSA doubling time significantly increased with treatment from a mean of 15 months at baseline to 54 months posttreatment (P < 0.001). In vitro assays comparing pretreatment and posttreatment patient serum on the growth of LNCaP showed a 12% decrease in cell proliferation and a 17% increase in apoptosis (P = 0.0048 and 0.0004, respectively), a 23% increase in serum nitric oxide (P = 0.0085), and significant (P < 0.02) reductions in oxidative state and sensitivity to oxidation of serum lipids after versus before pomegranate juice consumption.

Conclusions: We report the first clinical trial of pomegranate juice in patients with prostate cancer. The statistically significant prolongation of PSA doubling time, coupled with corresponding laboratory effects on prostate cancer in vitro cell proliferation and apoptosis as well as oxidative stress, warrant further testing in a placebo-controlled study.

(Juli 2006) (Opm. Bijzonder nieuws voor mannen met of met verhoogd risico op prostaatkanker, een effectief middel zonder enige bijwerking. Gelukkig is nu op veel plaatsen dit granaatappelsap te koop.)