We are inviting men to take part in this study who have already participated in the ProtecT and ProMPT studies. Men we are inviting either had a PSA (prostate specific antigen) result between 2.0 and 2.95 ng/ml or had a prostate biopsy without cancer being detected. Compared to men with very low PSA levels, these men are at higher risk of developing prostate cancer in the future. The ProDiet study is investigating whether that increased risk can be reduced through diet.
Modifying what you eat may help to reduce the risk of cancer. Two components of diet that have been investigated in cancer research are green tea and lycopene (found mostly in tomato products). The precise effects of these products on the prevention of prostate cancer are unknown, but some evidence suggests that they inhibit the growth of cancer cells. The ProDiet study is investigating the feasibility of increasing the amount of green tea and lycopene in men's diets, through supplements and dietary advice, and whether the results of that increase can be detected in blood tests.
Lycopene is a red carotenoid pigment (vegetable pigment) found mostly in tomatoes. It has antioxidant activity, which means that it can reduce damage to the DNA in the body's cells, and may prevent the process leading to the growth of cancer. Green tea contains several polyphenol catechins (another antioxidant plant substance). As with lycopene, these may act on the body's cells in order to inhibit tumour growth.
Hilary Moody, Study Nurse, School of Social and Community Medicine, University of Bristol, Bristol, BS8 2PS Tel: 0117 928 7272
Christine Croker, Study Secretary, School of Social and Community Medicine, University of Bristol, Bristol, BS8 2PS Tel: 0117 928 7272
Dr Athene Lane, Study Co-ordinator, School of Social and Community Medicine, University of Bristol, Bristol, BS8 2PS Tel: 0117 928 7335