Adherence to a healthful plant-based diet and risk of mortality among individuals with chronic kidney disease: A prospective cohort study

Background: Plant-rich dietary patterns may protect against negative health outcomes among individuals with chronic kidney disease (CKD), although aspects of plant-based diet quality have not been studied. This study aimed to examine associations between healthful and unhealthful plant-based dietary patterns with risk of mortality among CKD patients for the first time. Methods: This prospective analysis included 4,807 UK Biobank participants with CKD at baseline. We examined associations of adherence to both the healthful plant-based diet index (hPDI) and unhealthful plant-based diet index (uPDI), calculated from repeated 24-hour dietary assessments, with risk of mortality using multivariable Cox proportional hazard regression models. Results: Over a 10-year follow-up, 675 deaths were recorded. Participants with the highest hPDI scores had a 33% lower risk of mortality [HR (95% CI): 0.67 (0.53-0.84), p = <0.001], while those with the highest uPDI scores had a 49% higher risk [1.49 (1.18-1.89), p = 0.004], compared to participants with the lowest respective scores and following adjustment for other dietary and lifestyle factors. In food group-specific analyses, higher wholegrain intakes were associated with a 29% lower mortality risk, while intakes of refined grains, and sugar-sweetened beverages were associated a 28% and 31% higher risk, respectively. Conclusions: In CKD patients, a higher intake of healthy plant-based foods was associated with a lower risk of mortality, while a higher intake of unhealthy plant-based foods was associated with a higher risk. These results underscore the importance of plant food quality and support the potential role of healthy plant food consumption in the treatment and management of CKD to mitigate unfavourable outcomes.