Two simple changes -- lowering dietary fat and taking fish oil supplements -- can slow the spread of prostate cancer, a new study suggests.

Researchers fed some men with prostate cancer a diet comprised of just 15 percent fat, plus 5 grams of fish oil per day. The others got a typical Western diet high in fat. After four to six weeks, both groups underwent surgical removal of the prostate.

Researchers found a reduced rate of cancer cell proliferation in the excised glands of the men fed the low-fat, fish oil diets. .

"We are extremely encouraged by our findings that a low-fat diet with fish oil may have the potential to slow the progression of prostate cancer," says William Aronson, clinical professor of urology at the University of California Los Angeles Jonsson Comprehensive Cancer Center, who reported the findings in the journal Cancer Prevention Research.

Fish oil, high in omega-3 fatty acids, has been found to fight inflammation common in many cancers.