A narrative review published in The American Journal of Clinical Nutrition examined three decades of global research on the Mediterranean diet, synthesizing findings from large population-based cohort studies, randomized clinical trials, and biological analyses. The authors found consistent associations between the Mediterranean-style diet and reduced risks of cardiovascular disease, type 2 diabetes, cancer, cognitive decline, and all-cause mortality.
Unlike a systematic review or meta-analysis, this synthesis draws from a wide body of literature to provide a qualitative, integrated overview of the diet’s long-term health and environmental impact.
What Is the Mediterranean-Style Diet?
The Mediterranean diet emphasizes vegetables, fruits, whole grains, legumes, nuts, and olive oil, with moderate intake of fish and wine and limited consumption of red and processed meats. While originally rooted in the food traditions of Greece, southern Italy, and surrounding regions, the authors note that “Mediterranean-style diet” is a more appropriate term when applied outside the Mediterranean due to regional variations in ingredient access—especially olive oil.
The original Mediterranean Diet Pyramid, published in 1995, has informed dietary models in multiple regions and marked its 30th anniversary in 2024.
Cardiometabolic and Cognitive Benefits
The review highlighted findings from several large studies frequently cited in nutritional epidemiology:
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In the PREDIMED trial, individuals at high cardiovascular risk randomized to a Mediterranean-style diet supplemented with extra-virgin olive oil had a 31% lower risk of major cardiovascular events over five years, compared to a control group advised to follow a low-fat diet. However, the authors note that the control group’s fat intake averaged 37% of total energy, suggesting it functioned more as a usual care group than a true low-fat comparator.
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A secondary prevention trial, CORDIOPREV, found a 26% risk reduction in recurrent cardiovascular events among patients with coronary artery disease who followed the Mediterranean-style diet. A similar intervention with mixed nuts yielded a 28% risk reduction.
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Among 22,000+ Greek adults, higher adherence to the diet was associated with reduced cardiovascular and cancer mortality.
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The Nurses’ Health Study and Health Professionals Follow-Up Study, involving over 200,000 participants, found a 29% lower risk of coronary artery disease and a 17% lower risk of all-cause mortality with high adherence to the Mediterranean diet.
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A meta-analysis of 14 prospective studies (410,000+ participants) found a 21% reduced risk of type 2 diabetes among those with the highest adherence. Each 2-point increase in diet adherence score reduced risk by 14%.
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In cancer-related outcomes, a meta-analysis of more than 3.2 million individuals linked the diet to a 13% reduction in cancer mortality and lower risks for colorectal, breast, gastric, liver, head and neck, bladder, and respiratory cancers.
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Cognitive benefits were also noted. High adherence was associated with a 25% lower risk of mild cognitive impairment and a 29% lower risk of Alzheimer disease. Randomized trials reported improvements in memory performance.
Mechanisms: Omics and Olive Oil
Emerging omics research, including metabolomics and microbiome analysis, has helped uncover how the Mediterranean-style diet exerts its protective effects. Biomarker studies from the PREDIMED trial and U.S. cohorts show improvements in lipid metabolism, reductions in inflammatory markers, and positive shifts in gut microbiota composition.
Higher consumption of olive oil, a central feature of the diet, was independently associated with lower mortality from cardiovascular, cancer, and neurodegenerative diseases—even in U.S. populations where intake is typically lower than in the Mediterranean.
Beyond Health: Sustainability and Cultural Impact
In addition to its health effects, the Mediterranean-style diet aligns with planetary health goals. The review emphasizes the diet’s lower environmental footprint—especially its reduced reliance on animal products—leading to significantly lower greenhouse gas emissions and land use, as modeled in both international and Spanish studies. The review notes that olive groves, legumes, and tree nuts may contribute to soil health and carbon sequestration.
The MedDiet has also inspired the development of culturally adapted dietary pyramids in Asia, Africa, and Latin America. The “Planeterranean” diet, promoted by UNESCO, aims to apply the Mediterranean principles globally using regionally available foods to promote both health and sustainability.
Conclusion
The authors conclude that over the past 30 years, an extensive body of observational and interventional evidence has strongly supported the Mediterranean-style diet’s role in preventing chronic diseases and promoting healthy aging. While more long-term and culturally diverse trials are needed, the diet’s consistent benefits across disciplines—from public health to microbiome science to environmental sustainability—support its consideration as a dietary model for chronic disease prevention and healthy aging.
The authors reported no conflicts of interest.
