Healthful and Unhealthful Plant-Based Diets in Relation to Mortality Among Older Adults in China: A National Community-Based Prospective Study (2008-2018)

Background: Plant-based dietary pattern has been recommended for its potential health and environmental benefits. However, the relation of plant-based diet patterns to mortality warrants further exploration. Our study aimed to examine the prospective association of plant-based dietary patterns with all-cause mortality among older adults in China. Methods: In the Chinese Longitudinal Healthy Longevity Survey (CLHLS), we included a total of 13,154 participants with a mean follow-up of 5·7 years in our analysis. Death cases were ascertained through close family members or official death certificates during follow-up. Overall plant-based diet index (PDI), healthful plant-based diet index (hPDI), and unhealthful plant-based diet index (uPDI) were calculated to assess the dietary patterns. Multivariable time-varying Cox proportional hazard model was applied to estimate the corresponding hazard ratios (HRs) of mortality.Findings8,937 (67·94%) deaths occurred during a total of 74,056 person-years of follow-up. Compared with the lowest quintile, those in the highest quintile of PDI and hPDI had a decreased risk of all-cause mortality (HR pdi = 0·92, 95%CI: 0·87, 0·98; HR hpdi = 0·81, 95%CI: 0·76, 0·87), whereas higher uPDI was associated with an increased risk (HR Q5vsQ1 = 1·17, 95%CI: 1·10,1·26). Associations of PDIs with mortality risk were consistently observed across strata defined by gender, residence, smoking status, and history of major non-communicable disease. Interpretation: Higher adherence to a healthful plant-based diet was associated with a decreased risk of mortality, whereas an opposite association was observed for higher adherence to unhealthful plant-based diets. The quality, not only quantity, of plant-based diet should be emphasized in relevant public health recommendations. Funding: None to declare. Declaration of Interest: None to declare. Ethical Approval: The study was approved by the Biomedical Ethics Committee of Peking University, Beijing, China (IR1052-13074).