Mediterranean Diet

Regional foodways and the Keys era

A 1995 historical overview describes the diets of Mediterranean populations as a subject of interest since antiquity, and credits the work of Ancel Keys in the 1950s with establishing the largely plant-based Mediterranean diet as the original prototype for current dietary guidelines in the United States and elsewhere. The same overview warns that classic Mediterranean diets may be endangered by worldwide trends toward dietary uniformity.

The Cochrane review of Mediterranean-style diets states that the Seven Countries study in the 1960s showed lower coronary heart disease mortality in populations of the Mediterranean region, probably as a result of different dietary patterns, and that later observational studies and then clinical trials followed. The sources reviewed do not report the design details of the Seven Countries study itself, so it is described here only as these reviews characterize it.

Graphic representations and heritage recognition

A 2011 review presented a revised graphic representation of the diet, conceived as a simplified frame that could be adapted to different nutritional and socioeconomic contexts in the Mediterranean region. It added the idea of main meals built around a plant-based core, emphasized frugality and moderation, and included cultural and lifestyle elements such as conviviality, culinary activities, physical activity and adequate rest. The sources reviewed do not describe earlier pyramid versions, so their dates are not given here.

UNESCO lists the Mediterranean diet on the Representative List of the Intangible Cultural Heritage of Humanity, with inscription recorded in 2013 (8.COM). Its description covers skills, knowledge, rituals, symbols and traditions concerning crops, fishing, animal husbandry, food preservation, cooking and, above all, sharing meals. The page lists consent or inventory documents for Cyprus, Croatia, Spain, Greece, Italy, Morocco and Portugal, and includes a 2010 section naming Morocco, Italy, Greece and Spain. The 2011 review refers to the recognition as dating from 2010.

Names and working definitions

The pattern appears in the sources as the Mediterranean diet, the Mediterranean-style diet, MedDiet and, in United States guidelines, the Healthy Mediterranean-Style Dietary Pattern. The Cochrane review required two components for an intervention to count as Mediterranean-style: a high ratio of monounsaturated to saturated fat, from olive oil as the main cooking fat and/or foods such as tree nuts, and a high intake of plant foods including fruits, vegetables and legumes.

The same review listed additional components: low to moderate red wine, whole grains and cereals, low meat intake with more fish, and moderate dairy. Its authors note that the traditional diet is not low in fat, and that its distinguishing feature is a shift toward monounsaturated fat relative to saturated fat. Other studies and guidelines vary these elements, so the name does not identify one fixed set of foods.

Adherence scores

Researchers measure how closely people follow the pattern with scoring indices. An umbrella review of 14 publications, 27 meta-analyses and 70 primary cohort studies found substantial heterogeneity in the indices used, with two the most common: the Trichopoulou index and an alternative Mediterranean diet index. Subgroup comparisons showed little difference in associations between indices, and the authors advised future cohort studies to use more homogeneous definitions. Other scores, including the questionnaire-based screeners used in some trials, were not verified for this page.

Related Machipedia pages

On Machipedia this page is a member of the family page Dietary Approaches, which should be consulted for the wider group of eating patterns. DASH Diet, Plant-Based Diet and Anti-Inflammatory Diet have their own pages. The sources reviewed for this page do not compare these patterns with one another, so no equivalence between them is asserted here.

General features in guidelines

The Dietary Guidelines for Americans 2020-2025 present a Healthy U.S.-Style Dietary Pattern as the primary pattern and list the Healthy Mediterranean-Style Dietary Pattern as a variation with the same core elements. Those core elements are vegetables of all types, fruits, grains of which at least half are whole grain, dairy, protein foods including seafood, beans, nuts and seeds, and oils. The guidelines describe themselves as a framework to be customized to preferences, cultural traditions and budgets, not as prescriptive details.

A 2021 American Heart Association scientific statement stresses dietary patterns beyond individual foods or nutrients. Its pattern guidance favors plenty of fruits and vegetables, whole grains, mostly plant protein with regular fish and seafood, liquid plant oils, and minimally processed foods. The abstract reviewed does not name the Mediterranean diet, so this page does not state that the statement endorses it by name.

How trials delivered the pattern

In clinical trials the pattern has been delivered as advice, as provided foods, or both. The PREDIMED trial in Spain gave quarterly educational sessions and free extra-virgin olive oil or mixed nuts to the Mediterranean groups, while the control group received advice to reduce dietary fat. In CORDIOPREV, a team of dietitians delivered the dietary interventions, and the Lyon Diet Heart Study combined advice with a supplied canola margarine. These are trial designs, not instructions, and they show that results apply to packages of advice and foods.

Meals and food culture

UNESCO describes the practice as including the sharing of meals, with eating together presented as the foundation of the cultural identity and continuity of communities around the basin. It also lists hospitality, neighborliness, festivals, the making of traditional vessels, and markets as places where the practice is carried out and passed on, with women playing a major role in transmitting its techniques and values. Dietitians, who work in Dietetics, and practitioners of Nutritional Therapy may draw on the pattern, while Mindful Eating Therapy is a separate practice.

Cardiovascular prevention

The main studied use is the prevention of cardiovascular disease. The Cochrane review assessed Mediterranean-style diets for primary prevention in healthy adults and adults at increased risk, and for secondary prevention in adults with established disease. Observational studies have also examined associations with type 2 diabetes, cancer and cognitive-related diseases, and a meta-analysis has examined stroke.

Public health and cultural uses

Authors of the heritage-oriented review frame the diet as a lifestyle to adopt together with preserving its cultural elements, and the 1995 overview described it as a cultural model for dietary improvement. Claims that the pattern aids weight loss, lowers inflammation, or protects the brain were not assessed by the sources reviewed here and are not made on this page.

Individual randomized trials

The PREDIMED trial randomized 7447 adults aged 55 to 80 years at high cardiovascular risk in Spain to a Mediterranean diet with extra-virgin olive oil, a Mediterranean diet with mixed nuts, or a control diet of advice to reduce fat. The authors withdrew their 2013 report after finding protocol deviations, including household members enrolled without randomization and unrandomized assignment of some participants at 1 of 11 sites. The 2018 re-analysis, over a median 4.8 years, reported hazard ratios for major cardiovascular events of 0.69 (95% CI 0.53 to 0.91) with olive oil and 0.72 (0.54 to 0.95) with nuts.

The Cochrane review describes the Lyon Diet Heart Study as 605 people with coronary heart disease followed for 46 months, with low-quality evidence of lower adjusted cardiovascular and total mortality than usual care. CORDIOPREV, a single-centre Spanish trial of 1002 people with coronary heart disease followed for 7 years, reported fewer major events with a Mediterranean diet than a low-fat diet. Participants were not masked, and the abstract reports an effect in men but no difference among the 175 women.

Systematic reviews of trials

The Cochrane review included 30 randomized trials with 12,461 participants, searched to September 2018. Clinical endpoints were reported in only two trials. For the re-analyzed PREDIMED comparison it found low-quality evidence of little or no effect on cardiovascular or total mortality, and moderate-quality evidence of fewer strokes (hazard ratio 0.60, 95% CI 0.45 to 0.80). The authors concluded that some uncertainty remains for both primary and secondary prevention.

A 2024 meta-analysis of four randomized trials with 10,054 participants reported lower odds of a composite of major adverse cardiovascular events (odds ratio 0.52, 95% CI 0.32 to 0.84), but heterogeneity was high (I-squared 87 percent) and all-cause mortality showed no significant difference. Its authors acknowledged limits in the available trial evidence.

Observational evidence

The umbrella review of meta-analyses of cohort studies found that almost all reported inverse associations between the Mediterranean diet and chronic disease, but rated the credibility of the evidence as low to moderate. A 2025 meta-analysis of 30 cohort and case-control studies reported a pooled hazard ratio for stroke of 0.88 (95% CI 0.84 to 0.91) with higher adherence, and also flagged potential publication bias. These designs show association only.

Positions of health bodies

The Dietary Guidelines for Americans 2020-2025 include a Healthy Mediterranean-Style Dietary Pattern as a variation of the main pattern. The 2021 American Heart Association statement recommends dietary patterns that emphasize plant foods, fish, and limited processed foods. The World Health Organization healthy diet fact sheet, last dated 26 January 2026, does not mention the Mediterranean diet, and states that unsaturated fats are preferable to saturated and industrially produced trans fats. A position from NICE could not be verified for this page.

Reported adverse effects

The Cochrane review reports that two trials described adverse events, which were absent or minor, based on low- to moderate-quality evidence. In the Lyon Diet Heart Study, two of 302 patients in the Mediterranean group had colitis and diarrhea linked to the supplied margarine. No included trial reported costs or health-related quality of life. The few trials reporting harms do not establish how often problems occur in everyday use.

Alcohol, allergy and food components

Low to moderate red wine is listed in the Cochrane definition as an additional component, but it is not required. The American Heart Association statement advises that people who do not drink alcohol should not start and that those who drink should limit intake. The Dietary Guidelines state that adults of legal drinking age can choose not to drink or can drink in moderation, limiting intake to 2 drinks or less in a day for men and 1 drink or less in a day for women, that drinking less is better than drinking more, and that some adults, such as women who are pregnant, should not drink.

Tree nuts and fish feature in the definition and in trial interventions. A 2025 review of hazelnut allergy states that eating hazelnuts can be quite dangerous for allergic people. The sources reviewed do not describe fish allergy, so it is not covered here. A person with a food allergy would adapt the pattern with a clinician or dietitian.

Kidney disease and other medical conditions

A Cochrane review of dietary interventions in adults with chronic kidney disease included 17 studies with 1639 people, of which two studies with 355 people tested a Mediterranean diet. Risk of bias was generally high or unclear, adverse events were generally not reported, and effects on mortality and end-stage kidney disease were uncertain. The sources reviewed do not establish suitability for people with kidney disease, for people taking medicines, or for other medical conditions, so adaptation belongs with the treating clinician or dietitian. This page does not replace or delay necessary medical care.

Training and professional context

No training standard, register or professional title specific to the Mediterranean diet was found in the sources reviewed. The CORDIOPREV trial reports that dietitians delivered its interventions, and individual advice is the work of dietitians under Dietetics. Verified pages from dietitian professional bodies, such as codes of ethics and credentialing standards, could not be retrieved for this draft.