Associations of adherence to the EAT-Lancet and plant-based diets with mortality and life expectancy: two nationwide cohort studies.

The EAT-Lancet diet (ELD) and plant-based diets (PBDs) are recommended for their potential health and environmental benefits, but comparative analyses of these dietary patterns in relation to mortality risk remain limited. This study aimed to evaluate the associations of ELD and PBDs with mortality and life expectancy in two nationwide cohorts. Participants from the UK Biobank and the US National Health and Nutrition Examination Survey (NHANES) (2003-2018) were included. Dietary intake was assessed using 24-h dietary recalls. The ELD index (ELD-I), overall PBD index (PDI), healthful PBD index (hPDI), and unhealthful PBD index (uPDI) were calculated and categorized into tertiles. Primary outcomes were all-cause mortality, cause-specific mortality, and life expectancy. After full adjustment, the hazard ratio (HR) for all-cause mortality when comparing the highest versus lowest tertiles was 0.87 (95% CI 0.82-0.92) for ELD-I, 0.88 (0.83-0.93) for PDI, 0.90 (0.85-0.95) for hPDI, and 1.14 (1.02-1.21) for uPDI in the UK Biobank; equivalent HRs in the US NHANES were 0.71 (0.65-0.78), 0.71 (0.64-0.78), 0.83 (0.73-0.94), and 1.44 (1.32-1.57), respectively. In both cohorts, PDI was associated with a lower risk of cardiovascular disease mortality, while ELD-I showed inverse associations with cancer mortality and respiratory disease mortality. At age 45 years, participants with higher adherence to the ELD-I and PDI had an average increase in life expectancy of 2.07 to 4.31 years and 1.33 to 3.90 years, respectively. These findings demonstrated that greater adherence to ELD and overall PBD was associated with a lower risk of all-cause mortality and longer life expectancy across diverse populations, highlighting the significant benefits of these environmentally friendly diets for human longevity.