Is Mediterranean Diet good for longevity?

Yes — the evidence for this is strong. The Mediterranean diet is among the most rigorously studied dietary patterns in nutrition science, anchored by the PREDIMED randomized controlled trial, which found reduced cardiovascular events in high-risk adults, alongside decades of large cohort studies (including the influential Greek EPIC cohort) linking adherence to lower mortality. That's reflected in an evidence score of 89/100 for its role in longevity, drawn from 9 studies, with an estimated impact on longevity rated substantial (94/100).