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 all-cause mortality among CKD patients for the first time.

Methods
This prospective analysis included 4807 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-h dietary assessments, with risk of all-cause 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 showed a 34% lower risk of mortality [HRQ4vsQ1 (95% CI): 0.66 (0.52–0.83), ptrend <0.001]. Those with the highest uPDI scores had a 52% [1.52 (1.20–1.93), ptrend = 0.002] higher risk of mortality compared to participants with the lowest respective scores. 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 30% and 34% 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 less healthy plant-based foods was associated with a higher risk of mortality. 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.