Nearly all men, if they live long enough, develop prostate cancer. If you're one of the 'lucky' ones, the disease usually starts in your sixties and you'll have to take anti-androgens for the rest of your life. Not a great prospect, which is why there's growing interest in cheap, non-toxic supplements that inhibit prostate cancer. Researchers at Georgia State University have found a new one: ginger extract.
Men got the short end of the stick: their sexual organs house a ticking time bomb – the prostate. The gland grows with age and the bigger it gets, the greater the chance that the cells in the prostate turn into cancer cells. Men with a naturally high testosterone level are less likely to develop prostate cancer, according to epidemiological studies [Int J Cancer. 2004 Jan 20;108(3):418-24.], but in elderly men the opposite may be true. [Int J Cancer. 2008 May 15;122(10):2345-50.]
Some studies show that men who consume large amounts of synthetic folic acid [J Natl Cancer Inst. 2009 Mar 18;101(6):432-5.] and zinc [Eur Urol. 2007 Oct;52(4):1052-6.] are more likely to develop prostate cancer. That's why men who take large amounts of high-dose multi-vitamin supplements develop prostate cancer more often. [J Natl Cancer Inst 2007;99:754–64.] On the other hand, there are studies that suggest that fish oil, [Int J Cancer. 2007 Jan 15;120(2):398-405.] soya, magnesium and of course lycopene in tomato products [Cancer Res. 1999 Mar 15;59(6):1225-30.] can protect men against cancer. Add the animal studies too, then curcumin, a low-carb diet [Prostate. 2008 Jan 1;68(1):11-9.] and broccoli [Cancer Res. 2007 Jan 15;67(2):836-43.] are also interesting for men looking to reduce their risk of developing prostate cancer.
The British Journal of Nutrition is about to publish the results of an American study in which ginger [Zingiber officinale] extract killed human prostate cancer cells. The researchers did test-tube experiments on cells, and observed that more died at concentrations around 100 microgram/millilitre. Healthy prostate cells [PrEC] and human primary fibroblasts [HDT] did not die. GE = ginger-extract.
The researchers implanted human PC-3 prostate cancer cells in mice. Some of the mice were given daily oral doses of 100 mg ginger extract per kg bodyweight; others were given nothing. The experiment lasted eight weeks, during which time the extract halved the growth of the tumour. The human equivalent of this dose – based on a man weighing 70 kg – is 567 mg extract per day. A hundred grams of fresh ginger will give you this, the researchers have estimated.
The extract inhibited the synthesis of Cyclin B1, D1 and E. Cyclines are proteins that direct the development of a cell. Protein synthesis is higher in cancer cells. The extract boosted the concentration of p21 and active Caspase-3. These two proteins are active when cells commit suicide. Cancer cells deactivate these suicide mechanisms, but apparently ginger is capable of reactivating them.
"Our data present the potential usefulness of ginger extract in prostate cancer and warrant further studies", the researchers write.
Br J Nutr. 2011 Aug 18:1-12. [Epub ahead of print].