Associations of Plant- and Animal-Sourced Ultra-Processed Foods and Incident CKD in the Cardiovascular Health Study

Ultra-processed foods (UPFs) are associated with adverse health. Plant foods can be highly processed. It is not clear whether plant- and animal-sourced UPFs are associated chronic kidney disease (CKD) risk.

Data came from the Cardiovascular Health Study, a prospective cohort of 2,661 older adults (≥65 years). The exposure was UPF intake, classified as plant- or animal-sourced in servings/day using the Nova framework from food frequency questionnaires (1989-1990, 1995-1996). The outcome was incident CKD (estimated glomerular filtration rate [eGFR] <60 mL/min/1.73 m2) and absolute eGFR change (up to 18 years). Time-dependent Cox and linear models were used to examine the associations between total, plant-, and animal-sourced UPF, and minimally-processed food (MPF) intake with incident CKD and eGFR change.

After a median 6.8 years follow-up and adjusting for demographics and health behaviors, those in the highest tertiles of total and animal-sourced UPF intake had 26% and 37% higher risk of incident CKD compared to the lowest tertile (Hazard Ratio (HR) 1.26; 95% CI 1.08, 1.47; p-trend=0.003 and HR 1.37; 95% CI 1.17, 1.60; p-trend<0.001, respectively). Per standard deviation higher plant-sourced UPF was associated with higher CKD risk (HR 1.07; 95% CI 1.01, 1.13) but not in categorical analyses (p-trend=0.12). Higher total MPF was associated with 20% lower risk of incident CKD (HR 0.80 for tertile 3 vs. 1; 95% CI 0.69, 0.95; p-trend = 0.008). Replacing three servings of total MPF with total UPF (HR 1.02; 95% CI 1.001, 1.03, p=0.04) and plant-sourced MPF with plant-sourced UPF (HR 1.02; 95% CI 1.002, 1.05, p=0.03) was weakly associated with elevated risks of CKD. No associations were observed for eGFR change. Competing risks analyses for mortality attenuated estimates.

Total, and animal-sourced UPF were associated with incident CKD and plant-sourced UPF was modestly associated. Health benefits of plant foods may be dampened by ultra-processing, but additional work is needed in younger populations.