Kellogg Parsons, MD, MHS Professor of Urology Moores UC San Diego Comprehensive Cancer Center

Does Increased Vegetable Consumption Affect Prostate Cancer Progression? Interview with:

Kellogg Parsons, MD, MHS Professor of Urology Moores UC San Diego Comprehensive Cancer Center

Dr. Parsons

Kellogg Parsons, MD, MHS
Professor of Urology
Moores UC San Diego Comprehensive Cancer Center What is the background for this study?

Response: Clinical guidelines for prostate cancer, circulated widely in the public domain, endorse the consumption of diets high in micronutrient-enriched vegetables. Drawing on expert opinion, epidemiological studies, and small preclinical experiments, these recommendations propose that vegetable-enriched diets may decrease cancer progression and death among prostate cancer survivors. However, data from randomized clinical trials focused on actionable clinical endpoints has been lacking.

We utilized a specific behavioral intervention, grounded in the field of social psychology, to “nudge” patients with prostate cancer toward healthier food choices. The intervention is telephone-based, like a call center: patient-focused, convenient, and simple. What are the main findings?

Response: Two primary factors compelled us to explore this topic further. First, patient interest. One of the most common questions we receive from patients with prostate cancer is, “Are there any changes I can make to my diet to help fight the cancer?” Our team strived to provide an answer through the most rigorous, scientific process possible.

Second, the lack of prospective, Level 1 evidence on this topic. To our knowledge this study is the first randomized clinical trial to explore the effect of behavior change and diet on prostate cancer progression within a real-world context. What should readers take away from your report?

    • Diets supplemented by increased vegetable intake provided no disease-specific benefits to patients with localized prostate cancer on active surveillance.
    • This finding runs contrary to prevailing scientific and public opinion.
    • Nevertheless, we also demonstrated—for the first time—that a simple, inexpensive, and convenient behavioral intervention can lead patients with prostate cancer to adopt healthy diets.


Parsons JK, Zahrieh D, Mohler JL, et al. Effect of a Behavioral Intervention to Increase Vegetable Consumption on Cancer Progression Among Men With Early-Stage Prostate CancerThe MEAL Randomized Clinical TrialJAMA. 2020;323(2):140–148. doi:10.1001/jama.2019.20207 


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Last Updated on January 14, 2020 by Marie Benz MD FAAD