Plant-Based Diets Associated with Reduced Risk of Prostate Cancer Spreading

Prostate cancer is the second most common cancer among men in the U.S. A study of 2062 men with an average age 65.0, diagnosed with localized prostate cancer and followed in 43 different urology practices, found that the men with cancer who ate the most plant-based foods had a 47 percent reduced chance of having their prostate cancer spread in 6.5 years, compared to men who ate the least plant-based foods (JAMA Netw Open, June 1, 2024;7(5):e249053).

The authors strongly recommend that all men diagnosed with prostate cancer be instructed on plant-based diets. This study did not evaluate how much meat, eggs and dairy the men with prostate cancer ate, so it only shows that eating a lot of plants is associated with reduced prostate cancer spread.

Plant-based diets are generally recommended for most patients with cancers (Med Sci Sports Exerc. 2003;35(3):415-424) and more specifically, those with prostate cancer (Am J Epidemiol, 2012;176(3):240-252). Plant-based diets are also associated with a reduced death rate from prostate cancer (JAMA Intern Med, 2013;173(14):1318-1326).

Plant-Based Diets Reduce Prostate Cancer Risk
We have similar data on diet and risk of developing prostate cancer. A review of 32 studies found strong evidence that a plant-based diet is associated with reduced risk for developing prostate cancer in the first place (Prostate Cancer Prostatic Dis, 2022 Sep;25(3):444-452). Several studies also show that eating mammal meat is associated with increased risk of developing prostate cancer (Front Nutr, Feb 7, 2022;9:801722; Nutr Cancer, 2011; 63(4): 525-537).

How might a plant-based diet prevent spread and death from prostate cancer? Fruits and vegetables contain antioxidants, anti-inflammatory compounds (Nutr Cancer, 2011;63(6):860-872), and fiber (Nutrients, 2020;12(10):3209). Meat and dairy may be harmful because they have a lot of hormones and heterocyclic amines (Chimia (Aarau), 2018;72(10):718-724). Regular intake of meat is associated with insulin resistance and insulin-like growth factor-1, which are linked to increased risk for prostate cancer (Int J Epidemiol, 2023;52(1):71-86).

My Recommendations
All men may develop prostate cancer if they live long enough, but fewer than five percent of men will die from their prostate cancer. This recent study shows that eating lots of plants is associated with reduced risk of prostate cancer spreading in men who already have prostate cancer.