Broccoli helps prevent prostate cancer in high risk men
A recently published study presents the finding of a team led by Professor Richard Mithen at the Institute of Food Research of how broccoli helps reduce prostate cancer risk. Earlier research has shown that weekly consumption of broccoli, a member of the cruciferous family of vegetables, is associated with a lower risk of developing prostate cancer as well as a reduction in the progression of localized disease.
In the current study, 21 men with a diagnosis of high grade prostatic intraepithelial neoplasia (high grade PIN), a pre-invasive stage of localized prostate cancer, were divided to receive a diet containing 400 grams broccoli or 400 grams peas per week in addition to their normal diet. Blood or tissue samples obtained at the beginning of the study were evaluated for the presence of the glutathione S-transferase mu 1 (GSTM1) gene, which has been associated with obtaining a greater benefit from eating broccoli. Global gene expression in prostate tissue was analyzed at the beginning of the treatment period, and at six and twelve months.
Comparisons of prostate biopsy samples from beginning and end of the study showed significantly more gene changes that may be associated with a lower risk of cancer among men who consumed broccoli who had the GSTM1 gene, than in the group assigned to peas. The study is the first to demonstrate how broccoli reduces the risk of developing prostate cancer. "Other fruits and vegetables have been shown to also reduce the risk of prostate cancer and are likely to act through other mechanisms," Dr Mithen noted. "Once we understand these, we can provide much better dietary advice in which specific combinations of fruit and vegetable are likely to be particularly beneficial. Until then, eating two or three portions of cruciferous vegetable per week, and maybe a few more if you lack the GSTM1 gene, should be encouraged." The article is published July 2, 2008 in the online journal Public Library of Science One (PLoS ONE )