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| Pomegranate inhibits prostate cancer. |
Prostate cancer patients treated
Johns Hopkins Prostate Cancer Center researchers tested 104 men who had recurring prostate cancer. They were treated at multiple health centers. The patients – with an average age of about 75 years old – were given either one or three grams of a pomegranate extract for a year and a half.
Both pomegranate extract groups experienced a slowing of PSA growth after being treated with the extracts. Those taking the one-gram dose went from having their PSA levels doubling in about 12 months to their PSAs doubling in 18.8 months. The three-gram dose group also had a slowing of PSA growth – from an average of 12 months to 17.6 months.
In addition, 13% of the treated patients experienced a lowering of their PSA levels during the duration of the treatment.
Thi is significant, because PSA levels typically rise with time in older men. Healthy men in their fifties will experience PSA levels that rise about 3.3% per year. The median PSA level for men in this age group is about 1.0 ng/mL (nanograms of PSA per milliliter of blood).
This rate of rise (3.3%) equates to a typical PSA doubling rate of about 21 years.
Doubling PSA rates explained
Men who have been battling prostate cancer – the leading cause of cancer deaths among men – will experience a significantly higher PSA doubling rate than 3.3%. For example, 2007 research from the Mayo Clinic College of Medicine found that among men who had prostate cancer surgery, PSA doubling rates of less than three months came with an imminent risk of death, while patients with doubling rates of more than 10 years accompanied a low risk of prostate cancer recurrence.
Thus, an increase of average PSA doubling rates from around 12 months to nearly 19 months as a result of pomegranate extract supplementation is a significant finding – even though the researchers were confused that the three-gram dose did not produce a better result than the one gram dose.
This latter result – of benefits not increasing as doses go higher – has been observed in other research on natural medicinal products. The reason is often that the benefit derived from the natural product stems from a strengthening of the immune system, and a reduction in inflammation damage through antioxidant effects. Both of these results can have diminishing returns with higher doses.
But beyond this inflammation reduction with pomegranate lies an even greater potential benefit of pomegranate: Inhibiting prostate cancer – the leading cause of cancer death among elderly men.
Pomegranate extract tested in cancer cells
Scientists from the Biotechnology Department at the Southern Taiwan University of Science and Technology studied human prostate cancer cells in the laboratory. They found that pomegranate extract produced cell death among the prostate cancer cells. The mechanisms observed indicated genetic alteration, through a regulation of transcription factors along with an immunity protein called nuclear factor kappa-beta (NFκ-B).
Transcription factors attach to and carry gene sequences as instructional genes are transferred between genes and proteins. This is the essential process that cells use to perform their tasks, and regulating these processes allow cells to stop mutation and even switch on death sequences to eliminate cancer cells.
As we reported on previously, other studies have also showed pomegranates can slow the growth of prostate cancer.
Research from the University of California found that pomegranate juice can alter prostate cancer cells’ ability to adhere to tissues and migrate through the prostate. Their research also determined that pomegranate can alter cancer cells’ cytoskeletons.
Pomegranate accomplishes this through an alteration of cancer cell genetic factors. When the molecules known as E-cadherin and ICAM-1 (intercellular adhesion molecule 1) are altered, cancer cells can no longer organize and grow within prostate tissue.
The UC researchers also found that pomegranate inhibits pro-inflammatory cytokines such as IL-6 and IL-1β, slowing cancer cell growth.
Research from Portugal’s University of Porto found that pomegranate modulate Bcl-2 proteins while increasing the p21 and p27 pathways – producing cancer cell death. They also found that pomegranate inhibits the pro-inflammatory NFκ-B pathway.
Pomegranate is a medicinal food
Pomegranates have been used as medicinal foods for thousands of years. They are mentioned in Biblical scriptures and have been used in ancient Ayurveda for their bitter and astringent properties. They contain a variety of nutrients, including flavonoids and ellagitannins. Ellagitannins have been shown in other research to inhibit cancer cell growth. The USDA’s Agricultural Research Service found that pomegranates contain several phytonutrients that provide for its antioxidant and anti-inflammatory effects, including polyphenols like punicalagins, punicalins and gallagic acid in addition to ellagic acid.
REFERENCES:
Paller CJ, Ye X, Wozniak PJ, Gillespie BK, Sieber PR, Greengold RH, Stockton BR, Hertzman BL, Efros MD, Roper RP, Liker HR, Carducci MA. A randomized phase II study of pomegranate extract for men with rising PSA following initial therapy for localized prostate cancer. Prostate Cancer Prostatic Dis. 2012 Jun 12. doi:10.1038/pcan.2012.20.
Lee ST, Wu YL, Chien LH, Chen ST, Tzeng YK, Wu TF. Proteomic exploration of the impacts of pomegranate on gene expression of prostate cancer cell. Proteomics. 2012 Sep 4. doi: 10.1002/pmic.201200084.
Tollefson MK, Slezak JM, Leibovich BC, Zincke H, Blute ML. Stratification of patient risk based on prostate-specific antigen doubling time after radical retropubic prostatectomy. Mayo Clin Proc. 2007 Apr;82(4):422-7.
Wang L, Alcon A, Yuan H, Ho J, Li QJ, Martins-Green M. Cellular and molecular mechanisms of pomegranate juice-induced anti-metastatic effect on prostate cancer cells. Integr Biol (Camb). 2011 Jul;3(7):742-54.
Faria A, Calhau C. The bioactivity of pomegranate: impact on health and disease. Crit Rev Food Sci Nutr. 2011 Aug;51(7):626-34.
Adhami VM, Siddiqui IA, Syed DN, Lall RK, Mukhtar H. Oral infusion of pomegranate fruit extract inhibits prostate carcinogenesis in the TRAMP model. Carcinogenesis. 2012 Mar;33(3):644-51.
Johanningsmeier SD, Harris GK. Pomegranate as a functional food and nutraceutical source. Annu Rev Food Sci Technol. 2011;2:181-201.