Lycopene is an antioxidant found in red fruit, such as tomatoes and watermelon. In 2004, an analysis of 21 observational human studies found a small protective effect against prostate cancer . A year later a placebo-controlled trial involved giving 4mg of lycopene twice a day to 40 patients with high grade prostatic intraepithelial neoplasia (HGPIN), a pre-cancerous prostate condition. This led to a 66% reduction in risk of prostate cancer after one year . Lycopene was considered an effective agent in the treatment of HGPIN, with no toxicity or tolerability problems .
A more recent review of 13 observational studies concluded that there is evidence to support tomato and lycopene consumption in decreasing the risk of prostate cancer, but recommended larger studies are undertaken . A prospective study published in 2014 followed nearly 50,000 male health professionals, assessing lycopene intake though questionnaires looked at total and lethal prostate cancer cases from 1986 to 2010. Higher lycopene intake was inversely associated with the number of prostate cancers, but even more strongly with potentially lethal prostate cancer biomarkers. Only consumption of lycopene early or before diagnosis was inversely associated with these benefits .
During cancer animal studies have shown conflicting results, but in vitro work has identified pathways where lycopene plays an anti-cancer role [5,6].
In humans, 10mg lycopene a day was given to 20 prostate cancer patients; seventeen continued on the study (average six months). The average fall in prostate-specific antigen (PSA) was 32%, which was significant. The dose was also safe .
1. Etminan M, Takkouche B, Caamano-Isorna F. The role of tomato products and lycopene in the prevention of prostate cancer: a meta-analysis of observational studies. Cancer Epidemiol Biomarkers Prev 2004;13:340-345.
2. Mohanty N, Saxena S, Singh UP et al. Lycopene as a chemopreventive agent in the treatment of high-grade prostate intraepithelial neoplasia. Urol Onco 2005;23:383–385.
3. Kavanaugh CJ, Trumbo PR, Ellwood KC. The U.S. Food and Drug Administration’s evidence-based review for qualified health claims: tomatoes, lycopene, and cancer. J Natl Cancer Inst 2007; 99: 1074–85.
4. Zu K Mucci L, Rosner BA et al. Dietary lycopene, angiogenesis, and prostate cancer: a prospective study in the prostate-specific antigen era. J Natl Cancer Inst 2014;106(2):djt430.
5. Elgass S, Cooper A, Chopra M. Lycopene treatment of prostate cancer cell lines inhibits adhesion and migration properties of the cells. Int J Med Sci 2014; 2;11(9):948-54.
6. Renju GL, Muraleedhara Kurup G, Bandugula VR. Effect of lycopene isolated from Chlorella marina on proliferation and apoptosis in human prostate cancer cell line PC-3. Tumour Biol 2014. [Epub ahead of print July 30]
7. Zhang X, Yang Y, Wang Q. Lycopene can reduce prostate-specific antigen velocity in a phase II clinical study in Chinese population. Chin Med J (Engl) 2014;127(11):2143-6.
Green Tea contains polyphenols and the most abundant of these is EGCG (epigallocatechin gallate). There is much interest in the use of green tea and EGCG and its potential to decrease progression of disease in the prostate. Mechanisms of the anti-tumour action of green tea include apoptosis and cell cycle arrest via cancer pathways . Both in vivo and in vitro studies have provided convincing evidence of the potential benefits of EGCG from green tea. A recent in vivo study showed that a combination of green tea and quercetin, a methylation inhibitor, can increase prevention of prostate cancer with no side effects . A study of 130 patients with adenocarcinoma of the prostate and 274 non-cancer controls found that the risk of prostate cancer declined with increasing frequency, duration and quantity of green tea consumption . Green tea may therefore be of benefit to the general male population.
1. Johnson JJ, Bailey HH, Mukhtar H. Green tea polyphenols for prostate cancer chemoprevention: a translational perspective. Phytomedicine 2010; 17: 3–13.
2. Wang P, Vadgama JV, Said JW, Magyar CE, Doan N, Heber D, Henning SM. Enhanced inhibition of prostate cancer xenograft tumor growth by combining quercetin and green tea. J Nutr Biochem. 2014;2:73-80.
3. Jian L, Xie LP, Lee AH, Binns CW. Protective effect of green tea against Prostate Cancer: a case-control study in southeast China. Int J Cancer. 2004;108:130–135.
Pomegranate is a fruit studied for its supportive health properties towards the prostate gland.
The positive effects are thought to be due to the polyphenol gallic acid compounds inside pomegranates. Supplements provide a concentrated version of whole pomegranate fruit.
A large multi-center animal and in vitro study looked at the effect of three preparations of pomegranate. Significant induction of cancer cell death and changes in cell cycle were found . The potential of pomegranate polyphenols to inhibit gene expression in androgen receptors in advanced prostate cancer models has also been studied .
During human clinical cancer trials, a study of 46 patients with rising PSA levels after treatment for prostate cancer were given 8oz of pomegranate juice daily. This resulted in significant prolongation of the PSA doubling time, from mean 15 months to 54 months and longer stabilisation of the disease .
A placebo-controlled trial included 70 men who took two tablets of pomegranate extract or placebo, daily up to four weeks before radical prostatectomy. Results showed that pomegranate extract may be protective against oxidative prostate cell DNA damage .
A randomised controlled trial of 199 localised prostate cancer patients used a formulation containing pomegranate, green tea, turmeric and broccoli. It found that the percentage PSA rise was slowed in those on active surveillance and watchful waiting over six months. The median rise in PSA in the active supplement group was 14.7%, as opposed to 78.5% in the placebo group . It may therefore be beneficial for men to consume pomegranate products.
1. Albrecht M, Jiang W, Kumi-Diaka J et al. Pomegranate extracts potently suppress proliferation, xenograft growth, and invasion of human prostate cancer cells J Med Food. 2004;7:274-83.
2. Hong MY, Seeram NP, Heber D. Pomegranate polyphenols downregulate expression of androgen-synthesizing genes in human prostate cancer cells overexpressing the androgen receptor. J Nutr Biochem 2008 19, 848–855.
3. Pantuck AJ, Leppert JT, Zomorodian N et al. Phase II study of pomegranate juice for men with rising prostate-specific antigen following surgery or radiation for prostate cancer Clin Cancer Res. 2006;12:4018-26.
4. Freedland SJ, Carducci M, Kroeger N et al. A double-blind, randomized, neoadjuvant study of the tissue effects of POMx pills in men with prostate cancer before radical prostatectomy. Cancer Prev Res (Phila). 2013;6:1120-7.
5. Thomas R, Williams M, Sharma H et al. A double-blind, placebo-controlled randomised trial evaluating the effect of a polyphenol-rich whole food supplement on PSA progression in men with prostate cancer—the UK NCRN Pomi-T study. Prostate Cancer Prostatic Dis. 2014; 17(2): 180–186.
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