Environmental and Health Sustainability of the Mediterranean Diet: A Systematic Review

The Mediterranean diet (MD) has been shown to be a healthy dietary pattern (DP), and lately it is increasingly being studied as a sustainable DP. The aim of this study is to analyze whether the MD is a sustainable and healthy DP accounting for its carbon footprint, water footprint (WF), land use (LU), and/or energy use, based on the existing scientific literature. We conducted a systematic review following PRISMA guidelines and registered in PROSPERO (CRD42022309916). We included 35 studies: 25 modeling studies, 7 cross-sectional, and 3 longitudinal. Twenty-four studies compared the sustainability of the MD with that of other DPs; 21 assessed the sustainability of the MD compared with dietary consumption data; and 9 evaluated the MD's adherence and its environmental impacts. A total of 29 studies analyzed the carbon footprint, 11 the LU, 20 the WF, and 7 the energy use of the MD. Six articles assessed the health aspect of the diet apart from the environmental impact. The MD showed high nutritional quality, ranging between 122 and 178 points on the health score and between 13.51 and 90.6 points on the nutrient-rich food index. Using the results for environmental footprints in the same measurement units, we were able to quantitatively compare the most frequently assessed diets with MD. When compared with other diets, 91% of the studies referred to the MD as a sustainable DP, and most of the articles in which its adherence was assessed obtained an inverse correlation with the environmental footprints. Environmental footprints of the MD ranged from 1.03 to 5.08 kg CO2-eq/person-day for greenhouse gas emissions, 257.2-2735.2 L/person-day for WF, and 4-14.8 m²/person-day and 2.85-3.32 m²∗year/d for LU. In summary, the available evidence suggests that, in general, the MD is a sustainable and healthy DP, which aligns with planetary health.