ASCO 2023: Association of Plant-Based Diet Index with Quality of Life in Patients with Prostate Cancer

(UroToday.com) The 2023 ASCO annual meeting included a prostate cancer session, featuring a presentation by Dr. Stacy Loeb discussing the association of plant-based diet index with quality of life in patients with prostate cancer. Plant-based diets have many health benefits including a lower risk of fatal prostate cancer and improving erectile dysfunction. However, less is known about the relationship between diet and functional outcomes among prostate cancer survivors. Dr. Loeb and colleagues hypothesized that greater consumption of plant-based food after prostate cancer diagnosis is associated with improved quality of life.


This prospective cohort study included 3,505 participants in the Health Professionals Follow-up Study with non-metastatic prostate cancer (1986-2016). Overall and healthful Plant-based Diet Indices were calculated from food frequency questionnaires with cumulative updating. Quality of life scores were calculated using the Expanded Prostate Cancer Index Composite. Statistically, generalized estimating equations were used to examine associations between Plant-based Diet Indices and 5 quality of life domains (sexual, urinary incontinence and irritation, bowel, and hormone/vitality), and adjusted for age, PSA, Gleason score, stage, body mass index, physical activity, calories, smoking, alcohol, diabetes, heart disease, stroke, and hypertension.

 Among the groups of patients, the median age was late 60s, >90% were white, ~50% had a radical prostatectomy, 1/3 had radiation therapy, median body mass index was ~25 kg/m2, and only 1% were current smokers. The complete demographics are as follows:

plant based diet and prostate cancer.jpg

Higher Plant-Based Diet Index was associated with improved scores for sexual function (fully adjusted: Diff -0.36, p = 0.02), urinary irritation/obstruction (fully adjusted: Diff -0.21, p = 0.01), and urinary incontinence (fully adjusted: Diff -0.26, p = 0.03) among men with prostate cancer. Consuming more healthful plant-based foods was also associated with better scores for bowel function (age adjusted: Diff -0.41, p < 0.0001) and hormonal/vitality (age adjusted: Diff -0.29, p < 0.0001) in the age-adjusted models. Results were similar in sensitivity analyses excluding patients with pre-existing erectile dysfunction or lower urinary tract symptoms, and adjusting for the use of sexual or urinary medications. A limitation of this study is that no participants followed a strict vegan diet.

Dr. Loeb concluded her presentation by discussing the association of plant-based diet index with quality of life in patients with prostate cancer by highlighting that this prospective study suggests that greater consumption of healthful plant-based foods is associated with modest improvements in quality of life domains (sexual, urinary, bowel, and vitality) among patients with prostate cancer.

Presented by: Stacy Loeb, MD, New York University, New York, NY

Written by: Zachary Klaassen, MD, MSc – Urologic Oncologist, Associate Professor of Urology, Georgia Cancer Center, Augusta University/Medical College of Georgia, @zklaassen_md on Twitter during the 2023 American Society of Clinical Oncology (ASCO) Annual Meeting, Chicago, IL, Fri, June 2 – Tues, June 6, 2023.