The adoption of plant-based diets has surged in recent years, demonstrating potential benefits for individuals grappling with chronic conditions such as prostate cancer, a prevalent malignancy affecting men across the United States. Given the limited understanding of the relationship between plant-based diets and prostate cancer outcomes, this cohort study delved into the association between clinical trajectories in prostate cancer patients and postdiagnosis consumption of plant-based foods. The investigation centered on two key plant-based diet indices: the overall plant-based diet index (PDI) and the healthful plant-based index (hPDI).
In this comprehensive examination, researchers categorized food intake into plant-based diets by delineating 18 distinct groups based on nutritional commonalities. These groups were subsequently amalgamated into three broader categories: seven comprising healthy foods, five comprising unhealthy foods, and six comprising animal-based foods. The primary endpoint under scrutiny encompassed the progression of prostate cancer, encompassing parameters such as bone metastases, recurrence, and the initiation of secondary treatments. Additionally, mortality stemming from prostate cancer served as a secondary outcome measure.
Analyzing data garnered from multiple surveys administered over the years, a cohort of 2,062 participants (with a mean [IQR] age at diagnosis of 65.0 [59.0-70.0] years) who met the inclusion criteria emerged. Notably, PDI scores ranged from 27 to 76, while hPDI scores spanned from 29 to 84, with a moderate positive correlation observed between the two indices (r=0.34; P<.001). Comparing participants in the highest quintile to those in the lowest quintile revealed a noteworthy 47% reduced risk of prostate cancer progression (HR, 0.53; 95% CI, 0.37-0.74; P for trend=.003). Moreover, among 680 participants diagnosed with a Gleason grade of 7 or higher at diagnosis, those in the highest quintile exhibited a remarkable 55% decrease in cancer progression risk compared to their counterparts in the lowest quintile (HR 0.45; 95% CI, 0.25-0.81; P for trend=.01).
In summation, findings from this investigation underscore a compelling association between heightened consumption of plant-based foods postdiagnosis and diminished risk of prostate cancer progression among affected individuals. These insights shed light on the potential therapeutic role of plant-based diets in mitigating disease progression and merit further exploration in the realm of prostate cancer management and prevention.