Ultra-processed food consumption, genetic susceptibility, and the risk of hip/knee osteoarthritis

Background The associations between ultra-processed food (UPF) consumption, genetic susceptibility, and the risk of osteoarthritis (OA) remain unknown. This study was to examine the effect of UPF consumption, genetic susceptibility, and their interactions on hip/knee OA. Methods Cohort analyses included 163,987 participants from the UK Biobank. Participants' UPF consumption was derived from their 24-hour dietary recall using a questionnaire. Genetic risk scores (GRSs) of 70 and 83 single nucleotide polymorphisms (SNPs) for hip and knee OA were constructed. Findings After 1,461,447 person-years of follow-up, 11,540 patients developed OA. After adjustments, compared to participants in the low quartile of UPF consumption, those in the high quartile had a 10 % (hazard ratio [HR], 1.10; 95% confidence interval [CI], 1.03–1.18) increased risk of knee OA. No significant association was found between UPF consumption and hip OA. Replacing 20% of UPF diet weight with an equivalent proportion of unprocessed or minimally processed food caused a 6% (HR, 0.94; 95% CI, 0.89–0.98) decreased risk of knee OA, respectively. A significant interaction was found between UPF consumption, genetic predisposition, and the risk of knee OA (P = 0.01). Participants with lower OA-GRS scores experienced higher knee OA risks due to UPF consumption. Interpretation UPF consumption was associated with a higher risk of knee OA but not hip OA, particularly in those with lower genetic susceptibility. These results highlight the importance of reducing UPF consumption to prevent knee OA.