This prospective cohort study (nested in the Health Professionals Follow-Up Study) examined whether post-diagnosis dietary fat type was associated with long-term mortality in 4,884 men with nonmetastatic (T1–T3) prostate cancer, diagnosed 1986–2019 and followed through December 2022 (median 12.8 years).
Higher saturated fat intake (Q5 vs. Q1) was linked to greater all-cause mortality (HR 1.24, 95% CI 1.05–1.47) and cardiovascular mortality (HR 1.42, 95% CI 1.02–1.98). Substituting 5% of calories from saturated fat with monounsaturated fat reduced all-cause mortality (HR 0.80, 95% CI 0.70–0.91); substituting 10% of animal fat calories with plant-based fat also reduced it (HR 0.84, 95% CI 0.76–0.93). No dietary fat type was associated with prostate cancer–specific mortality.
- Observational design; residual confounding from unmeasured dietary and lifestyle factors cannot be excluded. - Study population was predominantly White male health professionals, limiting generalizability. - Dietary fat was measured by self-reported food frequency questionnaire every 4 years, introducing measurement error.
Counsel nonmetastatic prostate cancer survivors to shift away from saturated and animal fats toward plant-based and monounsaturated fat sources to lower cardiovascular and all-cause mortality risk. These changes will not affect prostate cancer–specific death but may meaningfully improve overall survival.
