Revisiting the associations between cooking oils and survival among older people in China: A nationwide, community-based, prospective cohort study

Abstract

Background The study aimed to investigate the associations between cooking oils and survival outcomes in a nationwide, community-based, prospective cohort study of older adults in China. Methods A total of 5372 older participants (median age: 85.0, inter-quartile range [IQR] age: 77.0–93.0; male: 46.1%) from the 2014 wave of the Chinese Longitudinal Healthy Longevity Survey (CLHLS) in 2014 were included, with follow-up until 2018. The exposure was cooking oils, including vegetable oils and lard, and outcomes were overall survival (OS) and disease-specific survival (i.e., cardiovascular disease [CVD]-specific survival and non-CVD-specific survival). Accelerated failure time (AFT) models were used to analyze the associations between cooking oils and study outcomes. Results During a median follow-up of 3.5 years (IQR: 2.4–4.2 years), 2064 (38.4%) deaths were recorded, including 433 CVD deaths, 1229 non-CVD deaths, and 402 deaths with unknown causes. Kaplan-Meier analysis revealed cooking with lard was associated a higher CVD-specific survival probability than vegetable oils (93.9% vs. 88.2%, log-rank p < 0.001); however, there were no significant differences in OS and non-CVD-specific survival between the two groups (log-rank p = 0.076 and 0.210, respectively). Furthermore, multivariate AFT models indicated cooking with lard was significantly associated with a longer CVD-specific survival compared to vegetable oils (time ratio [TR]=1.44, 95% confidence interval [CI]: 1.08–1.91), and was not associated with OS and non-CVD-specific survival, with adjusted TRs of 1.06 (95% CI: 0.95–1.18) for OS and 1.08 (95% CI: 0.93–1.26) for non-CVD-specific survival, respectively. Conclusions Cooking with lard was associated with significantly longer CVD- specific survival compared to vegetable oils among older adults in China.