Prostate Cancer:  Pomegranate Juice

It has been suggested that Pomegranate Juice offers some prospect for slowing the progress of prostate and other cancers.  Here are some relevant links.  Please note from the Disclaimer that the main aim of my website is to provide information for researchers - as such, I conclude by raising some puzzles.

• For some simplified information on prostate cancer - see  BBC News, 15 Dec 2003.  Botanical and horticultural information on pomegranate can be found at the AgroForestryTree Database.  The tree makes a handsome bonsai.

• In studies at the Rambam Medical Center in Haifa, the juice of the pomegranate was found to slow down cholesterol oxidation by almost half, and reduce the retention of LDL.  Preliminary studies suggest that pomegranate juice may contain almost three times the total antioxidant ability compared to the same quantity of green tea or red wine - see BBC News 28 Nov 2004.  The site also gives a brief background to the fruit.

• Researchers at the University of  Wisconsin (See BBC News 26 Sep 2005)found that :

  • the juice kills laboratory cultures of human prostate cancer cells

  • the progress of cancer was significantly reduced in mice receiving a supplement of 0.2% of the juice in water, as measured by the PSA marker

• Researchers at the University of California suggested that drinking a daily (0.24 litre/about 8 ounce) glass of pomegranate juice can significantly slow the progress of prostate cancer - see BBC News, 1 July 2006.  Funding was received from a company which makes pomegranate juice for a 3-year study involving 50 men experiencing a return of the disease after surgery and/or radiotherapy.  After drinking the juice, the PSA level doubling time increased from 15 to 54 months, indicating a slower progress of the cancer.  Some men who did not receive any other treatment showed suppressed PSA levels even after 3 years.  This provides some scope for avoiding or delaying the need for hormone treatment and chemotherapy which can have harmful side effects.  See Cancer Research UK site for side-effects of hormone treatment.

• The wiki page on Pomegranate includes links to research suggesting other health benefits, such as the lowering of systolic pressure and the slowing of arthritis.  Researchers at the University of Wisconsin also found that oral consumption of pomegranate fruit extract inhibits growth and progression of primary lung tumours in mice (see Cancer Research, 27 March 2007).

Contraindications: 

• There are several varieties of pomegranate -  http://www.soymilkquick.com/pomegranatejuice.html  This site also gives some helpful tips on choosing fruit.

• In much the same way in which varieties of fruit, such as apples and mango, have very different characteristics, I wonder whether some varieties may be better than others, while some may not be suitable.  The juice of the pomegranate is known to vary in sourness.  Some varieties of mango, like some crab apples, can have unpleasant effects on some people.  I personally find that grapefruit and citrus varieties (such as mandarin and tangerine) suit me, while most other citrus fruit cause reactions, such as sensitive teeth, sore gums, heartburn, colitis and cystitis.  It makes me grind my teeth to alleviate tension.

• I also get sore gums and throat when I eat pomegranate or drink the the juice.  Yet, the fruit is used in traditional medicine for treating sore gums and for fastening loose teeth (as reported in article by Jeannie Graham).  This paradox may be explained by the idea that "like cures like" which was first proposed by Hippocrates in 4th Century BC.  Hahnemann, who founded Homeopathy, affirmed the law of similars which states that the symptoms induced by a given homeopathic remedy in a group of healthy individuals will cure a similar set of symptoms in the sick (British Homeopathic Association; but there are excellent books on this subject).  Perhaps, my reactions were 'proving' the remedy. 

• Pomegranate is astringent and acidic - like litmus paper, it is said to turn blue when subjected to alkaline conditions (wiki).  The juice may not suit all constitutions, so there is a need for further research on juice intolerance/allergy.
• Although the University of California research suggests no side effects, new evidence suggests that pomegranate juice may interact with certain medications, much like grapefruit juice does -see Harvard Health Publication, 1 April 2007.  For side effects of grapefruit juice see The People's Pharmacy.  Pomegranate juice and grapefruit juice, are both known to block the cytochrome P450 3A4 enzyme systems in the intestines. By inhibiting these enzymes, the juices may increase blood levels of many medications - from a report published in the September 1 2006 issue of the American Journal of Cardiology cited in http://altmedicine.about.com/od/druginteractions/a/pom_interaction.htm.  This can cause health problems, including myopathy (neuromuscular disorders) and kidney failure.
• Some side effects of pomegranate are noted in Loyola University site.

Another puzzle

• Here is another puzzle.  Prostate cancer feeds on the male sex hormone, testosterone, produced by the testicles in response to a signalling hormone produced by the pituitary gland.  The aim of hormone therapy is to use another hormone to block this signal (see  Cancer Research UK, Goserelin (Zoladex) for prostate cancer.  One side effect of this is impotence and reduced sexual drive.  An article in ProstrateCommons.com reports on doctors' views that hormone treatment is perhaps being overused and that it increases the risk of heart disease, diabetes and osteoporosis.

Paradoxically, pomegranate is a symbol of abundance, fertility and procreation in Greece, Armenia, the Middle East and China.  Sairam (1998: 232) notes that fresh fruit juice increases and improves the blood content.  It has usually been taken as a delicacy and has been regarded as an aphrodisiac and as a tonic (see item 5 under reasons why pomegranate is good for you in ChennaiOnline).  These fanciful ideas may be based on the appearance of the fruit (as explained on some web sites) rather than on experimental observations. 

However, if they are founded on observed outcomes, scientific research is needed to cast light on what appear to be puzzling contradictions.  If pomegranate juice has no effect or increases testosterone levels, it contradicts the premises on which Zoladex use is based.  The effectiveness of both treatments are monitored using PSA levels as markers.  However, PSA levels are only indicators, not foolproof measures.  Only a biopsy can truly diagnose prostate cancer.   It could be that the effectiveness of one or the other of the treatments may be due to factors unrelated to testosterone. 

Conclusion and Research Topics

All parts of the pomegranate tree have been used since ancient times in herbal medicine.  The discovery that the juice might delay the progress of prostate and other cancers is new.  If this symbol of fertility and fecundity can arrest the progress of cancer, it would be a boon to men suffering the side effects of Zoladex.  While science-based medicine does not hesitate to promote regular consumption of sponsors' products on very limited evidence without thorough testing for contraindications, it is all too dismissive of the potential value of alternative medicines, such as homeopathic cures - see Controversy over NHS funding for Alternative Medicines.  To my knowledge, pomegranate does not as yet feature in the catalogue of homeopathic remedies.  Homeopathic provings, while identifying potential applications, might also indicate the kind of person who might have adverse reactions to the juice. 

Research Topics

1. The advice of an 8oz glass of juice a day is too vague; what is the recommended level of concentration?
2. Potential side effects of pomegranate juice
3. Allergy or intolerance of pomegranate
4. Contraindications and reactions to other medicines.
5. Homeopathic proving of pomegranate juice
6. Pomegranate juice lowers PSA levels but this is not a totally reliable indicator.  Given that the current hormone therapy is targeted as reducing the level of testosterone, perhaps the effect of pomegranate juice on testosterone should be evaluated.
7. Varieties of pomegranate which have been in long use and other varieties (such as the wild form) which has only been used in medicine and not for regular consumption as a supplement.
8. What is the incidence of prostate cancer in countries (such as Iran and Turkey) where the fruit and juice have been traditionally consumed.  There are other questions which can be posed as a follow up.

Other sources of information on prostate cancer
 

Cancer Research UK - provides information on incidence, mortality, survival, risk factors, treatment, and screening & prevention.  The information on diet is under risk factors. 

University of York - research on gene therapy; found that the principal cause of cancer is the structure that controls the papilloma virus which causes warts (see National Cancer Institute).  As I have noted on my page on warts, there are many types of warts; most of these do not become cancerous. 

Disclaimer

© Mahes Visvalingam, 8 Jun 2007
Last updated on 16/09/07