Association of cooking oil and incident of frailty in older adults: a cohort study

Abstract Background Studies examining the potential association between cooking oil and frailty risk in older adults have produced conflicting outcomes. Therefore, our objective was to explore the relationship between cooking oil (vegetable and animal fat oils), changes in oil usage, and the risk of frailty in older adults. Methods We included 4,838 participants aged ≥ 65 years without frailty (frailty index < 0.25) from the 2011 wave of the Chinese Longitudinal Healthy Longevity Survey. Follow-up occurred in the 2014 and 2018 waves. Cox proportional hazard models were utilized to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) to examine the association between cooking oil and frailty. Additionally, we evaluated the effect of switching cooking oil on frailty during the follow-up period. Results During a median follow-up of 3.0 (2.8–6.9) years, 1,348 individuals (27.9%) developed frailty. Compared to those using vegetable oil, users of animal fat oil had a lower risk of frailty (HR = 0.72, 95% CI: 0.61–0.85). Participants who switched from vegetable oil to animal fat oil, as well as those consistently using animal fat oil, had lower risks of frailty with HRs of 0.70 (0.52–0.95) and 0.63 (0.51–0.77) respectively, compared to those who consistently used vegetable oil. Conversely, individuals who switched from animal fat oil to vegetable oil experienced an increased risk of frailty (HR: 1.41, 95% CI: 1.01–1.97). Conclusions The utilization of animal fat oil in cooking exhibited a reduced frailty risk among older adults. Conversely, transitioning from animal fat oil to vegetable oil may elevate the risk. These findings propose that substituting vegetable oil with animal fat oil in the diet may safeguard against frailty.