Vegetable Fats May Reduce Mortality Risk in Prostate Cancer Patients
Researchers say nuts are better than meat (June 10)
Replacing carbohydrates and animal fat with vegetable fat — such as that found in nuts and olive oil — may reduce the risk of all-cause mortality in men with non-metastatic prostate cancer, according to a new study published in JAMA Internal Medicine.
Researchers at the University of California–San Francisco found that switching 10% of daily calories from carbohydrates to vegetable fat was associated with a 29% lower risk of lethal prostate cancer and a 26% lower chance of dying from any cause. Conversely, replacing 5% of those calories with saturated fat, or just 1% with trans fat, led to a 25% to 30% higher risk of death during the study period. Saturated and trans fats are often found in meat and processed foods.
Until now, little was known about the association between diet after diagnosis and prostate cancer progression and overall mortality. Therefore, the investigators conducted a prospective analysis of 4,577 men with non-metastatic prostate cancer in the Health Professionals Follow-up Study (1986–2010). During a median follow-up period of 8.4 years, 315 events of lethal prostate cancer and 1,064 deaths were observed.
In the highest and lowest quintiles of fat intake, the crude rates per 1,000 person-years of lethal prostate cancer were 7.6 vs. 7.3, respectively, for saturated fat; 6.4 vs. 7.2 for monounsaturated fat; 5.8 vs. 8.2 for polyunsaturated fat; 8.7 vs. 6.1 for trans fat; 8.3 vs. 5.7 for animal fat; and 4.7 vs. 8.7 for vegetable fat.
For all-cause mortality, the rates were 28.4 vs. 21.4 for saturated, 20.0 vs. 23.7 for monounsaturated, 17.1 vs. 29.4 for polyunsaturated, 32.4 vs. 17.1 for trans, 32.0 vs. 17.2 for animal, and 15.4 vs. 32.7 for vegetable fat.
Replacing 10% of energy intake from carbohydrates with vegetable fat was associated with a significantly lower risk of lethal prostate cancer (hazard ratio [HR], 0.71; P = 0.04) and all-cause mortality (HR, 0.74; P = 0.001). Saturated and trans fats after diagnosis (replacing 5% and 1% of energy from carbohydrate, respectively) were associated with significantly higher all-cause mortality (HR, 1.30; P = 0.02; and HR, 1.25; P = 0.01, respectively).
Vegetable fats contain antioxidants and may reduce inflammation in the body, thereby making it harder for cancer to spread, the authors suggest.