The association between adherence to the planetary health diet and chronic kidney disease (CKD) remains under characterized. This study aim to investigate the association of planetary health diet index (PHDI) with the risk of CKD and assess potential effect modification by genetic predisposition.

A large, population-based cohort study was conducted using data from UK Biobank. Eligible participants included those without a history of CKD who completed at least one 24 -h dietary recall questionnaire.

Three distinct planetary health diet indexes (PHDIs) were used to assess dietary adherence. A polygenic risk score (PRS) for CKD was calculated to evaluate genetic susceptibility. Cox proportional hazards models were used to estimate the associations between the PHDI and the risk of incident CKD. The joint effects of PHDI and genetic susceptibility were further examined. Sensitivity analyses were conducted to evaluate the robustness of the findings.

A total of 139,165 participants were included in the primary analysis. Over a median follow-up of 13.3 years, 6,391 incident CKD cases were identified. Compared with participants in the lowest adherence category, the hazard ratios (HRs) of incident CKD for those in highest adherence were 0.827 (95% CI, 0.757−0.904), 0.865 (95% CI, 0.805−0.929), and 0.891 (95% CI, 0.821−0.996) for Stubbendorff PHDI, Colizzi PHDI and Knuppel PHDI, respectively. Participants with highest adherence to planetary health diet and low genetic risk showed the lowest risk of CKD, with HRs of 0.707 (95% CI, 0.600−0.832), 0.682 (95% CI, 0.597−0.778), and 0.770 (95% CI, 0.663−0.893) across the three different PHDIs. These associations remained robust in several sensitivity analyses.

Higher adherence to the planetary health diet was associated with lower risk of CKD, and these effects were enhanced by jointing with genetic susceptibility. Promoting this sustainable dietary pattern may play a key strategy for CKD prevention.