The Mediterranean diet is a diet inspired by the eating habits and traditional food typical of southern Spain, southern Italy, and Crete, and formulated in the early 1960s. It is distinct from Mediterranean cuisine, which covers the actual cuisines of the Mediterranean countries. While inspired by a specific time and place, the "Mediterranean diet" was later refined based on the results of multiple scientific studies.
The principal aspects of this diet include proportionally high consumption of unprocessed cereals, legumes, olive oil, fruits, and vegetables, and moderate consumption of fish, dairy products (mostly cheese and yogurt), and meat products. Olive oil has been studied as a potential health factor for reducing all-cause mortality and the risk of chronic diseases.
The Mediterranean diet is associated with a reduction in all-cause mortality in observational studies. In 2017, the European Journal of Clinical Nutrition published evidence that the Mediterranean diet lowers the risk of heart disease and early death. The Mediterranean diet may help with weight loss in obese people. The Mediterranean diet is one of three healthy diets recommended in the 2015–2020 Dietary Guidelines for Americans, along with the DASH diet and vegetarian diet. The Mediterranean and DASH diets are two of the main sources for the MIND diet recommendations.
The Mediterranean diet as a nutritional recommendation, that is, as a particular set of foods, is different from the cultural practices that UNESCO listed in 2010 under the heading "Mediterranean diet" on the Representative List of the Intangible Cultural Heritage of Humanity: "a set of skills, knowledge, rituals, symbols and traditions concerning crops, harvesting, fishing, animal husbandry, conservation, processing, cooking, and particularly the sharing and consumption of food".
Health effects
A 2017 review found evidence that practice of a Mediterranean diet could lead to a decreased risk of cardiovascular diseases, overall cancer incidence, neurodegenerative diseases, diabetes, and early death. A 2018 review showed that practice of the Mediterranean diet may improve overall health status, such as reduced risk of non-infectious diseases, reduced total costs of living, and reduced costs for national healthcare. A 2016 review found similar weight loss as other diets. A 2019 Cochrane review found that there is still uncertainty regarding the effects of Mediterranean‐style diet advice on cardiovascular disease occurrence and risk factors in people both with and without cardiovascular disease already.
The US 2015–2020 national guidelines devised a "Healthy Mediterranean-Style Eating Pattern", assessed against and mirroring the Mediterranean diet patterns and its positive health outcomes. It was designed from the "Healthy U.S.-Style Eating Pattern", but it contains more fruits and seafood, and less dairy. In the 2020s, research on the Mediterranean diet indicates that a Mediterranean diet may contribute to health.
Cardiovascular disease
The Mediterranean diet is included among dietary patterns that may reduce the risk of cardiovascular diseases. A 2013 Cochrane review found limited evidence that a Mediterranean diet favorably affects cardiovascular risk factors. A 2013 meta-analysis compared Mediterranean, vegan, vegetarian, low-glycemic index, low-carbohydrate, high-fiber, and high-protein diets with control diets. The research concluded that Mediterranean, low-carbohydrate, low-glycemic index, and high-protein diets are effective in improving markers of risk for cardiovascular disease and diabetes, while there was limited evidence for an effect of vegetarian diets on glycemic control and lipid levels unrelated to weight loss. However, more cautious reviews arose in early 2016, raising concerns about the quality of previous systematic reviews examining the impact of a Mediterranean diet on cardiovascular risk factors. These reviews insisted upon the need for further standardized research, stating that the evidence for possible prevention of cardiovascular disease by the diet was "limited and highly variable". Reviews in 2016-17 reached similar conclusions about the ability of a Mediterranean diet to improve cardiovascular risk factors, such as lowering the risk for hypertension and other cardiovascular diseases.