Plant‐based diet associated with better quality of life in prostate cancer survivors

Abstract Background Plant‐based diets have many health benefits, including a lower risk of fatal prostate cancer, and greater environmental sustainability. However, less is known regarding the impact of plant‐based diets on quality of life among individuals diagnosed with prostate cancer. The authors' objective was to examine the relationship between plant‐based diet indices postdiagnosis with quality of life. Methods This prospective cohort study included 3505 participants in the Health Professionals Follow‐Up Study (1986–2016) with nonmetastatic prostate cancer. Food‐frequency questionnaires were used to calculate overall and healthful plant‐based diet indices. Quality‐of‐life scores were calculated using the Expanded Prostate Cancer Index Composite. Generalized estimating equations were used to examine associations over time between plant‐based diet indices and quality‐of‐life domains (sexual functioning, urinary irritation/obstruction, urinary incontinence, bowel functioning, hormonal/vitality), adjusted for demographics, oncologic history, body mass index, caloric intake, health‐related behaviors, and comorbidities. Results The median age at prostate cancer diagnosis was 68 years; 48% of patients underwent radical prostatectomy, and 35% received radiation as primary therapy. The median time from diagnosis/treatment to first the quality‐of‐life questionnaire was 7.0 years. A higher plant‐based diet index was associated with better scores for sexual function, urinary irritation/obstruction, urinary incontinence, and hormonal/vitality. Consuming more healthful plant‐based foods was also associated with better sexual and bowel function, as well as urinary incontinence and hormonal/vitality scores in the age‐adjusted analysis, but not in the multivariable analysis. Conclusions This prospective study provides supportive evidence that greater consumption of healthful plant‐based foods is associated with modestly higher scores in quality‐of‐life domains among patients with prostate cancer.