DAVIS, Calif., March 24 (UPI) -- A study in mice found walnuts slowed prostate tumors by 30 percent to 40 percent, U.S. researchers said.
Paul Davis of the University of California, Davis, said not only was prostate cancer growth reduced, but the mice had lower blood levels of a protein -- insulin-like growth factor -- strongly associated with prostate cancer.
Davis and colleagues said walnuts -- rich in omega-3 polyunsaturated fats, antioxidants and other plant chemicals -- had an effect on the gene activity in the prostate tumors with beneficial effects on genes related to controlling tumor growth and metabolism. The findings provide additional evidence walnuts -- already shown to be good for the heart -- may be high in fat, but healthful.
"This study shows that when mice with prostate tumors consume an amount of walnuts that could easily be eaten by a man, tumor growth is controlled," Davis said in a statement. "This leaves me very hopeful that it could be beneficial in patients."
For 18 weeks, Davis fed mice genetically programmed to get prostate cancer either a diet with whole walnuts -- the human equivalent of eating 2.4 ounces of walnuts per day -- or a diet with an equal amount of fat, but not from walnuts.
The findings were presented at the annual national meeting of the American Chemical Society in San Francisco.