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

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.

Effect of Fuel Preheating on Engine Characteristics of Waste Animal Fat-Oil Biodiesel in Compression Ignition Engine.

The present study aims at understanding the effects of fuel preheating on engine characteristics of waste animal fat-oil (WAF-O) biodiesel in a single-cylinder CI engine, with the preheating technique proposed as an effective means for enhancing the fuel properties. To understand the effects of the preheated fuel, the WAF-O biodiesel was preheated at 60, 80, 100 and 120 °C and tested along with neat diesel and unheated WAF-O biodiesel. For this purpose, biodiesel was produced from different animal wastes by means of KOH-assisted ethanol-based transesterification, reporting its maximum yield as 96.37 ± 1.8%, with significant distribution of unsaturated oleic acid, saturated palmitic acid and stearic acid. Upon evaluating its fuel characteristics as per ASTM D6751 standards, a rise in preheating temperature by 1 °C reduced the density and kinematic viscosity of WAF-O biodiesel by 0.383 kg/m3 and 0.025 mm2/s, respectively, and was explained by the weakening of intermolecular forces between its fatty acid ester molecules. Preheated samples reported superior combustion characteristics by exhibiting increased in-cylinder pressure (2.24%, on average) and heat release rates in addition to their shortened ignition delay (1−4 °CA). Furthermore, preheating of WAF-O biodiesel reduced its specific fuel consumption and increased its brake thermal efficiency by 7.86% (on average) and 9.23% (on average), respectively. However, higher preheating temperatures (>120 °C) resulted in increased fuel consumption owing to its varied flow characteristics. In addition to the changes in combustion characteristics, preheating WAF-O bio-diesel also resulted in reduced carbon monoxide, nitrous oxide and hydrocarbon emission by 13.88%, 7.21% and 26.94%, respectively, and increased carbon dioxide emission by 7.58%. Summing up, the enhancements in overall engine characteristics of preheated samples were accounted for by their improvised fuel injection characteristics due to their reduced density and viscosity, which ensured for their effective combustion.