Onions, garlic cut prostate cancer risk

Men who eat plenty of onions, garlic and similar foods may irritate their romantic partners but they cut their risk of prostate cancer in half, researchers have reported.

Men who eat the most vegetables containing allium - the pungent, sulphur-based compound blamed for the antisocial effects of garlic and onions - are 50 per cent less likely to get prostate cancer than those who eat the least, the study found.

Ann Hsing of the US National Cancer Institute and her colleagues interviewed 238 men with prostate cancer and 471 men without it about what they ate.

Men who ate more than 10g a day of onions, garlic, chives or scallions were much less likely to be in the cancer group, Hsing reported in the Journal of the National Cancer Institute.

This adds to research showing the right diet can reduce the risk of cancer, said the American Institute for Cancer Research, which investigates links between cancer and diet.

"Several case-control studies [in which the diets of cancer patients were compared to the diets of healthy individuals] have linked allium vegetables to lower risk for cancer of the stomach, colon, oesophagus, breast and endometrium [lining of the uterus]," the group said.

Bad news for prostate cancer patients is that a team at the University of Rochester, New York, has found some drugs used to treat prostate cancer can in fact cause it to grow.

"It's a real surprise that the same compound that kills cancer cells also makes them grow," said Chawnshang Chang, who led the study. "The effect of the drug reverses completely."

His team studied a drug called flutamide, made by Schering, but he said other similar drugs were likely to have a similar effect.

A treatment for prostate cancer is castration using drugs or surgery to cut off testosterone. The hormone fuels the growth of prostate cancer cells in many cases. But for reasons that doctors have not understood, after one or two years the cancer cells often start growing again.

"In all of the more than 30,000 [US] men who die of prostate cancer each year, the cancer cells have become capable of growing even when we starve the cells of testosterone," said Dr Edward Messing, a urology professor at Rochester.

Yi-Fen Lee, who worked on the study, said the findings did not mean prostate cancer patients should avoid flutamide or similar drugs.

"These drugs are necessary for patients who otherwise have few options. Perhaps these findings will help lead to a new drug target so men with this disease can be treated more effectively."

- REUTERS

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