Designer diet for prostate cancer
rpautrey2
Designer diet for prostate cancer
Eating one or more portions of broccoli every week can reduce the risk
of prostate cancer, and the risk of localised cancer becoming more
aggressive.
For the first time, a research group at the Institute of Food Research
led by Professor Richard Mithen has provided an explanation of how
eating broccoli might reduce cancer risk based upon studies in men, as
opposed to trying to extrapolate from animal models. Prostate cancer
is the most common non-skin cancer for males in western countries. The
research has provided an insight into why eating broccoli can help men
stay healthy.
For the study, published in the online, open-access journal PLoS ONE
on July 2, men who were at risk of developing prostate cancer ate
either 400g of broccoli or 400g of peas per week in addition to their
normal diet over 12 months. Tissue samples were taken from their
prostate gland before the start of the trial and after 6 and 12
months, and the expression of every gene measured using Affymetrix
microarray technology.
It was found that there were more changes in gene expression in men
who were on the broccoli-rich diet than on the pea diet, and these
changes may be associated with the reduction in the risk of developing
cancer, that has been reported in epidemiological studies.
Previous studies have suggested that the fifty percent of the
population who have a GSTM1 gene gain more benefit from eating
broccoli than those who lack this gene. The study showed that the
presence of the GSTM1 gene had a profound effect on the changes in
gene expression caused by eating broccoli.
This study fills the gap between observational studies and studies
with cell and animal models. While observational studies have shown
that diets rich in cruciferous vegetables may reduce the risk of
prostate cancer and other chronic disease, they do not provide an
explanation of how this occurs. Evidence from animal and cell models
has sought to provide an explanation, but these studies are usually
based on high doses that would not normally be experienced as part of
the diet.
The results of the study suggested that relatively low amounts of
cruciferous vegetables in the diet – a few portions per week – can
have large effects on gene expression by changing cell signalling
pathways. These signalling pathways are the routes by which
information is transmitted through a molecular cascade which amplifies
the signal to the nucleus of the cell where gene expression occurs.
The Norwich-based team are currently planning a larger study with men
with localised prostate cancer, and will compare the activity of
standard broccoli with the special variety of high glucosinolate
broccoli used in the current study.
Designer studies for health promotion
"Other fruits and vegetables have been shown to also reduce the risk
of prostate cancer and are likely to act through other mechanisms,"
says Professor Mithen.
"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."
Citation: Traka M, Gasper AV, Melchini A, Bacon JR, Needs PW, et al.
(2008) Broccoli Consumption Interacts with GSTM1 to Perturb Oncogenic
Signalling Pathways in the Prostate. PLoS ONE 3(7): e2568. doi:10.1371/
journal.pone.0002568
Source: Public Library of Science
This news is brought to you by PhysOrg.com