Association of Planetary Health Diet with Decreased Risk of All-cause Mortality and Environmental Benefits: Insights...

Whether adherence to the Planetary Health Diet (PHD) benefits human and environmental health is less known. We included 131,130 adults from the National Health and Nutrition Examination Survey and UK Biobank. Adherence to the PHD was measured using the Planetary Health Diet Index (PHDI) and mortality was ascertained by linking to national registries. Cox proportional hazards and linear/ordinal logistic regression models were used to analyze the association between PHD and the risk of mortality and environmental impacts, respectively. During a median follow-up of 10.6 years, participants in higher adherence groups (Quartile 2: hazard ratio = 0.88, 95% confidence interval = 0.82-0.95; Quartile 3: 0.87, 0.82-0.93; Quartile 4: 0.70, 0.54-0.92) had a lower risk of mortality, compared to Quartile 1. The relationship between the PHDI and mortality showed linearity in the two cohorts ( P = 0.1877 and 0.5456, respectively), and body mass index mediated 11.88% of the relationship. A higher PHDI was associated with lower greenhouse gas emissions but higher freshwater use. Our findings suggest that greater compliance with the PHD reduces mortality risk; however, its benefits for environmental sustainability are less certain.