Association of Plant-Based Diet Index with Prostate Cancer Risk.

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

To examine the relationship between Plant-based Diet Indices and prostate cancer risk, including clinically relevant disease.

This was a prospective cohort study including 47,239 men in the Health Professionals Follow-up Study (1986-2014). Overall and healthful Plant-based Diet Indices were calculated from food frequency questionnaires. Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) to examine the risk of incident prostate cancer (total and by clinical category), among men ages < 65 and ≥ 65.

6,655 men were diagnosed with prostate cancer over follow-up, including 515 with advanced stage at diagnosis, 956 with lethal disease (metastasis or death) and 806 prostate cancer deaths. Greater overall plant-based consumption was associated with a significantly lower risk of fatal prostate cancer (HR 0.81, 95% CI 0.64,1.01; p-trend = 0.04). In men age < 65, higher Plant-based Diet Index was associated with a lower risk of advanced, lethal and fatal prostate cancer. Moreover, greater consumption of a healthful plant-based diet was associated with lower risks of total (HR 0.84; 95% CI 0.73,0.98; P-trend = 0.046) and lethal prostate cancer (HR 0.56; 95% CI 0.34,0.94; P-trend = 0.03) at age < 65. There were no associations between overall or healthful Plant-based Diet Indices with prostate cancer among men ≥ 65 years. Less than 1% of participants followed a strict vegetarian or vegan diet.

This prospective study provides supportive evidence that greater consumption of healthful plant-based foods is associated with a lower risk of aggressive forms of prostate cancer, with stronger benefit among men age < 65.

The American journal of clinical nutrition. 2021 Nov 13 [Epub ahead of print]

Stacy Loeb, Benjamin C Fu, Scott R Bauer, Claire H Pernar, June M Chan, Erin L Van Blarigan, Edward L Giovannucci, Stacey A Kenfield, Lorelei A Mucci

Department of Urology and Population Health, New York University and Manhattan Veterans Affairs, NY, NY, USA., Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA, USA., Department of Medicine and Urology, UCSF; Division of General Internal Medicine, San Francisco VA Healthcare System, USA., Departments of Epidemiology and Biostatistics, and Urology, University of California, San Francisco, San Francisco, CA, USA., Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA.