Plant-Based and Planetary-Health Diets, Environmental Burden, and Risk of Mortality: A Prospective Study in Chinaplant-Based and Planetary-Health Diets, Environmental Burden, and Risk of Mortality: A Prospective Study in China

Background: Plant-based and planetary-health diets (PBDs and PHD) are recommended for their potential health and environmental benefits, but population-based evidence in various cultures and developmental contexts is limited.Methods: We included 9420 adults aged >=45 years (52·3% female) from the open cohort of the China Health and Nutrition Survey. Dietary intake was assessed using 3-day 24-hour dietary recalls combined with weighing methods from 1997 to 2011, and mortality was documented until 2015. We calculated overall, healthful, and unhealthful PBD indices (PDI, hPDI, and uPDI, range: 18-90) and PHD score (range: 0-140), estimated their related greenhouse gas (GHG) emissions, land appropriation (LA), and total water footprint (TWF), and examined their associations with mortality. Findings: PBD indices were inversely related to GHG emissions , LA, and TWF, whereas higher PHD score was related to higher environmental burdens (P-trends <0·0001). During follow-up (mean = 9·2 years), 800 (8·5%) death cases were documented. PDI and hPDI were not significantly associated with mortality (hazard ratio for highest vs. lowest quartile = 1·10, 95% confidence interval: 0·90-1·35 for PDI and 0·97, 0·79-1·20 for hPDI), whereas higher uPDI was related to higher mortality risk (1·56, 1·27-1·93). In contrast, higher PHD score was associated with lower mortality risk (0·68, 95% CI: 0·53-0·86).Interpretation: The environmentally friendly PBDs are not necessarily associated with lower mortality risk. The PHD, developed mainly based on Western populations, was related to lower mortality risk but higher environmental burdens in the Chinese population.Funding: This study was supported by National Natural Science Foundation of China (72273126) (granted to XW); Fundamental Research Funds from the Central Universities of Zhejiang University and Zhejiang University Global Partnership Fund (granted to CY).Declaration of Interest: The authors declare no competing interests.