Plant-based diets are associated with multiple health benefits as well as a favorable environmental impact. For prostate cancer, previous studies suggest a beneficial role of specific plant-based foods (e.g., tomatoes with lycopene) and a potentially harmful role of specific animal-based foods (e.g., meat and dairy). However, less is known about plant-based dietary patterns and prostate cancer risk.


This was a prospective study including 47,243 men followed for up to 28 years in the Health Professionals Follow-up Study. Plant-based dietary indices were calculated using data from food frequency questionnaires collected every four years. Cox proportional hazards models were used to calculate multivariable hazard ratios (HR) and 95% confidence intervals (CI) of the association between plant-based diet in relation to risk of incident prostate cancer. A priori we hypothesized that a plant-based diet would be associated with a lower risk of advanced, lethal and fatal cancers, and among men less than 65 years at diagnosis.


A total of 6,660 men were diagnosed with prostate cancer over follow-up, including 516 with advanced stage at diagnosis, 958 with lethal disease and 807 deaths from prostate cancer. There was no association between the overall plant-based dietary index with total prostate cancer risk, although greater overall plant-based consumption was associated with a nonsignificant lower risk of fatal prostate cancer. In men age less than 65 at diagnosis, greater overall consumption of plant-based diet was associated with a lower risk of advanced prostate cancer (HR 0.68, 95% CI 0.42-1.10, p-trend=0.046). Moreover, among younger men, greater consumption of a healthful plant-based diet was associated with lower risks of total prostate cancer (HR 0.81; 95% CI 0.70-0.95, p-trend=0.01) and fatal disease (HR 0.53; 95% CI 0.32-0.90, p-trend=0.03). There were no associations with either the overall or healthful plant-based diet indices with prostate cancer among men older than 65 years. Limitations of the study include that <1% of the participants followed a strict vegetarian or vegan diet.


In addition to well-established benefits for general health and the environment, data from this prospective study provide supportive evidence that greater consumption of healthful plant-based foods may be associated with a lower risk of total and fatal prostate cancer among younger men.

Source of Funding:

This work was supported by grants from the National Institutes of Health (U01 CA167552, T32 CA009001). SL and LAM are supported by the Prostate Cancer Foundation. SB is supported by grant 1K12DK111028 from the National Institute of Diabetes, Digestive, and Kidney Disorders