A Diet Rich in Vegetables and Fruit and Incident CKD: A Community-Based Prospective Cohort Study

Rationale & Objective: A diet rich in vegetables and fruit can lower blood pressure and may reduce cardiovascular risk. However, the association between this dietary pattern and incident chronic kidney disease in the general population is unknown. Study Design: A community-based prospective cohort study. Setting & Participants: 9,229 study participants with normal kidney function from the Korean Genome and Epidemiology Study database. Predictors: Daily consumption of nonfermented and fermented vegetables and fruit classified into tertiles based on a validated semiquantitative food-frequency questionnaire. Outcomes: Incident occurrence of estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m(2), incident proteinuria (>= 1+ by dipstick test), and repeated measures of estimated net endogenous acid production. Analytical Approach: Multivariable cause-specific hazards model to assess the association of vegetable and fruit intake with incident chronic kidney disease. Results: During a mean follow-up of 8.2 years, 1,741 (21.9/1,000 person-years [PY]) participants developed eGFRs < 60 mL/min/1.73 m(2). Incident eGFR < 60 mL/min/1.73 m(2) occurred less frequently with higher intake of nonfermented vegetables, occurring at rates of 22.8/1,000 PY, 22.7/1,000 PY, and 20.1/1,000 PY for the lowest, middle, and highest tertiles, respectively; P for trend < 0.001. The incidence of proteinuria was also lower in the middle and highest tertiles. In a multivariable cause-specific hazards model, the highest tertile of nonfermented vegetable intake was associated with 14% lower risk for incident eGFR < 60 mL/min/1.73 m(2) than the lowest tertile. The highest tertile was also associated with 32% lower risk for proteinuria than the lowest tertile. There were no associations of fermented vegetable and fruit intake with incidence of eGFR < 60 mL/min/1.73 m(2). However, the highest tertiles of both fermented vegetable and fruit intake were associated with 14% and 45% lower risks for incident proteinuria compared with the lowest tertiles (both P < 0.001). During follow-up, estimated net endogenous acid production increased in the lowest tertile of intake of nonfermented or fermented vegetables and fruit, whereas it decreased in the highest tertile. Limitations: Self-reported dietary intake, single ethnicity population. Conclusions: A diet rich in vegetables and fruit may reduce the risk for kidney disease.