Men who eat more healthy fats from vegetables, nuts and olive oil after a diagnosis of prostate cancer see better survival rates than peers whose diets are unchanged, a US study says.
The findings in the Journal of the American Medical Association (JAMA) Internal Medicine suggest that dietary improvements can be an important way to lower the death risk among men whose prostate cancer has not spread.
"Consumption of healthy oils and nuts increases plasma antioxidants and reduces insulin and inflammation, which may deter prostate cancer progression," said lead author Erin Richman, a postdoctoral scholar in the University of California San Francisco Department of Epidemiology and Biostatistics.
The study involved 4577 men who had been diagnosed with non-metastatic prostate cancer between 1986 and 2010.
Researchers found that men who replaced 10 per cent of their total daily calories from carbohydrates with healthy vegetable fats had a 29 per cent lower risk of developing lethal prostate cancer.
They also had a 26 per cent lower risk of dying from all causes.
The effects were seen even in small changes: adding one tablespoon of oil-based dressing per day was associated with a 29 per cent lower risk of lethal prostate cancer and a 13 per cent lower risk of death.
Adding one ounce of nuts per day was linked to an 18 per cent lower risk of lethal prostate cancer and an 11 per cent lower death risk.
Healthy vegetable fats included olive and canola oils, nuts, seeds and avocados.
"The beneficial effects of unsaturated fats and harmful effects of saturated and trans fats on cardiovascular health are well known," Richman said.
"Now our research has shown additional potential benefits of consuming unsaturated fats among men with prostate cancer."
About 2.5 million men are living with prostate cancer in the United States, and nearly 30,000 are expected to die from it this year.
Although one in six men will be diagnosed with prostate cancer in their lifetime, most do not die from it.
In the JAMA study, less than a quarter of participants - a total of 1064 men - died during the research period: 31 per cent from cardiovascular disease, 21 per cent from prostate cancer and 21 per cent from other cancers.