THURSDAY, May 15 (HealthDay News) -- Eating less polyunsaturated fat, the kind often found in baked and fried goods, helps prevent prostate cancer in mice, according to researchers.

The finding by University of California, Los Angeles, scientists is believed to be the first of its kind in a mouse model that closely mimics human cancer.

The fat used in the study, published in the April 15 issue of the Cancer Research, came mostly from corn oil, which is made up primarily of omega-6 fatty acids -- the polyunsaturated fat commonly found in Western diets.

Mice that ate a low-fat diet, in which just 12 percent of their calories come from fat, had a 27 percent reduced incidence of prostate cancer compared to mice who ate a more traditional Western-type diet, in which 40 percent of the calories came from fat.

Research also found that precancerous prostate cells, or those that would soon become cancer, grew much more slowly in the mice eating the low-fat diet.

"A low-fat, high-fiber diet combined with weight loss and exercise is well known to be healthy in terms of heart disease and is known to reduce the risk of heart attacks and strokes, so that would be a healthy choice to make," study senior author William Aronson, a Jonsson Cancer Center researcher, said in a prepared statement. "Whether or not it will prevent prostate cancer in humans remains to be seen."

Previous studies done in Aronson's lab showed that a low-fat diet slowed the growth of aggressive human prostate cancers in mice and helped them live longer.

Aronson found that mice on the low-fat diet had higher levels of a protein in their blood that binds to insulin during the time when the precancerous prostate lesions usually develop. Aronson believes the low-fat diet caused the increase in the binding protein, and the protein helped prevent prostate cancer from thriving.

A short-term study in men assigned either a diet high in polyunsaturated fat or a low-fat diet with fish oil supplements will now take place to further determine whether diets affect malignant and benign human prostate tissue, Aronson said.

"We're looking at specific markers and growth factors in human tissue known to be important for development and progression of prostate cancer," he said. "It's this work we hope will lead to longer term prevention strategies incorporating dietary changes."

More information

The National Cancer Institute has more about prostate cancer.

SOURCE: University of California, Los Angeles, news release, May 15, 2008