Association between habitual adherence to the planetary health diet and mortality and major chronic disease risk among UK Biobank participants

Background: Since a healthy diet is a key contributor to human health and risk of developing noncommunicable diseases, the EAT-Lancet Commission proposed the "planetary health diet" (PHD) in 2019. The literature on the association between the PHD and risk for health outcomes is sparse and diverse. Objectives: To increase the knowledge of the potential effects of the PHD on human health, we analyzed data from a prospective cohort study, investigating whether habitual adherence to the PHD was associated with health outcomes among participants in the UK Biobank cohort study. Methods: Depending on the health outcome, between 196,099 and 204,778 participants of the UK Biobank, aged 39-72 y at recruitment, were included. The UK Biobank Oxford WebQ 24-h dietary assessment data was used to define a scoring system, ranging from 0 to 14 points that reflects participants' habitual adherence to the PHD. Habitual dietary intake was determined by using the Multiple Source Method. Cox proportional hazards regression models were fitted to investigate the association of adherence to the PHD with all-cause mortality, cancer risk, and cardiovascular disease (CVD) risk. Results: For every 1-point increase in the PHD score, a 3% lower all-cause mortality (hazard ratio (HR): 0.97; 95% confidence interval (CI): 0.96, 0.99) and a 9% lower lung cancer risk (HR: 0.91; 95% CI: 0.87, 0.96) were observed. A trend between adherence to the PHD and all-cancer risk (HR: 0.99; 95% CI: 0.98, 1.00) and a null association between PHD adherence and CVD risk (HR: 0.99; 95% CI: 0.96, 1.02) were found. Conclusions: Our results point toward an inverse association between habitual adherence to the PHD and all-cause mortality and cancer risk, although the associations with cancer depended on the cancer type. Our study provides additional evidence that sustainable diets can improve human health.