WASHINGTON (Reuters) - Men who eat plenty of onions,
garlic and similar foods may irritate their romantic partners but may cut their
risk of prostate cancer in half, researchers reported on Wednesday.
Men who ate the most vegetables containing allium --
the pungent, sulfur-based compound blamed for the antisocial effects of garlic
and onions -- had a 50 percent lower risk of having prostate cancer than those
who ate the least, the study found.
Ann Hsing of the National Cancer Institute and colleagues interviewed 238 men with prostate cancer and 471 men
without prostate cancer about what they ate.
Men who ate more than a third of an ounce (10 grams)
a day of onions, garlic, chives or scallions were much less likely to be in the
cancer group, Hsing reported in Wednesday's issue of the Journal of the National
Cancer Institute.
This adds to research showing the right diet can
reduce the risk of cancer, the American Institute for Cancer Research, which
investigates the links between cancer and diet, said.
"Several case-control studies (in which the diets of
cancer patients are compared to the diets of healthy individuals) have linked
allium vegetables to lower risk for cancer of the stomach, colon, esophagus,
breast and endometrium (lining of the uterus)," the group said in a statement.
Jamie Bearse of the prostate cancer coalition
agreed.
"It's great to see that more flavorable foods are
proving to be preventatives for prostate cancer," he said in a statement. "Maybe
it will encourage men to put down that Big Mac and pick up a salad with chives
and onions."
In a piece of bad news for prostate cancer patients,
a team at the University of Rochester in New York 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," Chawnshang Chang, who led the study,
said in a statement. "The effect of the drug reverses completely."
His team studied a drug called flutamide, made by
Schering, but he said other, similar drugs are likely to have a similar effect.
A common 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 men who die of prostate cancer each year, the
cancer cells have become capable of growing even when we starve the cells of
testosterone," Dr. Edward Messing, a urology professor at Rochester, said.
Writing in the journal Cancer Research, Chang and colleagues said they may
have an explanation. Flutamide cuts off testosterone by targeting a protein
known as the androgen receptor. But it also turns on MAP kinase -- an enzyme
that promotes cell growth and is known to play a role in breast and prostate
cancer.
Yi-Fen Lee, who worked on the study, said the findings do not mean prostate
cancer patients should avoid flutamide or similar drugs.
"These drugs are necessary for patients who otherwise have few options," Lee
said. "Perhaps these findings will help lead to a new drug target so that men
with this disease can be treated more effectively."
