Health and environmental dietary impact: Planetary health diet vs. Mediterranean diet. A nationwide cohort in Spain

Author links open overlay panelMaría del Carmen Aznar de la Riera a, Rosario Ortolá a b, Stefanos N. Kales d, Auxiliadora Graciani a, Jesús Diaz-Gutierrez e, José R. Banegas a b, Fernando Rodríguez-Artalejo a b c, Mercedes Sotos-Prieto a b c dShow morehttps://doi.org/10.1016/j.scitotenv.2025.178924Get rights and contentHighlights•

The PHDI and the Med have shown to similarly reduce all-cause mortality risk.

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Similar reduced GHGE and LU result from adhering to these plant-based diets.

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Traditional diets like the Med already support health and environmental benefits.

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Each population’s customs are key when assessing health and environmental impacts.

AbstractBackground

Plant-based diets, such as the Planetary Health Diet (PHDI) and the Mediterranean Diet (Med), offer notable advantages for human and planetary health. However, knowledge on the PHDI’s benefits is limited, particularly in Southern European countries where the Med is culturally rooted and is an environmentally sustainable dietary pattern.

Objective

to evaluate the association of both PHDI and Med with mortality and assess their environmental burden in the adult population of Spain.

Methods

Data were taken from the study on Nutrition and Cardiovascular Risk in Spain (ENRICA) comprising 13,105 participants representative of the Spanish adult population. The PHDI score (0–140 points) was based on 15 food groups, while adherence to Med was assessed with the 14-item MEDAS score (0–14 points). Environmental impact was assessed using the SHARP-ID database (including greenhouse gas emissions and land use). Analyses were performed with Cox regression and adjusted for main confounders.

Results

During a mean 14.4-year follow-up, 1157 all-cause deaths occurred. The mortality hazard ratio (95 % CI) for the highest vs lowest tertile of the PHDI score was 0.78 (0.66, 0.91) but reached a plateau level at 90 points of PHDI. For the MEDAS, the corresponding results for the highest vs lowest tertile was 0.79 (0.68, 0.93) with a continuous inverse dose-response association. Adherence to some components of the PHDI (fruits, dairy, and unsaturated oils) and of MEDAS (nuts, and low consumption of soda and pastries) was independently and significantly associated with lower mortality. Results remained robust in sensitivity analyses. In terms of environmental impact, both plant-based diets had similar low footprints, with dairy and meat products being the largest contributors.

Conclusion

In this large cohort of Spanish adults, higher adherence to the PHDI and MEDAS was similarly associated with lower all-cause mortality and showed comparable low environmental impact.

Keywords

Planetary health diet

Mediterranean diet

Plant-based diet

Environment

Environmental health

Non-communicable diseases