Broccoli 'could help fight cancer'

Broccoli may combat prostate cancer by altering the activity levels of genes involved in tumour growth, a ground-breaking study has shown.
Scientists made the discovery after adding either peas or broccoli to the normal diets of two groups of men for a year.
During the study tissue samples were removed from the men's prostate glands and analysed using "gene chip" technology to gauge the activity of thousands of genes. The results showed that a broccoli-rich diet produced changes in gene activity, or expression, that were likely to prevent or hinder cancer growth and inflammation in the prostate.
In particular, biological signalling pathways involving two growth factors, TGF beta 1 and EGF, as well as the hormone insulin, were altered.
Growth factors are proteins that typically stimulate cell division or development, and often play a role in cancer. TGF beta 1, EGF and insulin signalling have all been implicated in prostate and other cancers.
Messenger RNA - the molecule that carries genetic instructions to protein-making machinery in the cell - was also affected by eating broccoli, the scientists found. The implications of this are still being investigated.
Before the study it was already known that eating as little as one portion of broccoli every week can reduce the risk of prostate cancer, and lessen the chances of confined cancer becoming more aggressive.
However scientists have been unable to explain with any certainty how the process works. Animal and laboratory experiments have suggested possible mechanisms but involved doses of broccoli extract far in excess of what would be consumed in real life.
The new study is said to be the first in which gene expression in a target tissue has been studied after a dietary intervention.
Professor Richard Mithen, from the Institute of Food Research in Norwich, who led the British and Italian team, said: "This is the first study providing experimental evidence obtained in humans that diets rich in cruciferous vegetables may reduce the risk of prostate cancer."