Mediterranean diet

Some ingredients that form a large part of the Mediterranean diet

The Mediterranean diet is a concept first proposed in 1975 by American biologist Ancel Keys and chemist Margaret Keys. It is inspired by the eating habits and traditional foods of Greece, Italy, and the Mediterranean coasts of France and Spain, as observed in the late 1950s to early 1960s.<ref>Template:Cite book</ref><ref>Template:Cite journal</ref> The diet is distinct from Mediterranean cuisine, which encompasses the diverse culinary traditions of Mediterranean countries,<ref>Template:Cite web</ref> and from the Atlantic diet of northwestern Spain and Portugal, albeit with some shared characteristics.<ref>Template:Cite web</ref> The Mediterranean diet is the most well-known and researched dietary pattern in the world.<ref>Template:Cite journal</ref>

While based on a specific time and place, the "Mediterranean diet" generically describes an eating pattern that has been refined based on the results of multiple scientific studies.<ref>Template:Cite web</ref> It emphasizes plant-based foods, particularly unprocessed cereals, legumes, vegetables, and fruits;<ref name="cc">Template:Cite web</ref> moderate consumption of fish and dairy products (mostly cheese and yogurt); and low amounts of red meat, refined grains, and sugar.<ref name=cc/><ref>Template:Cite web</ref> Alcohol intake is limited to wine (typically the red variety) consumed in low to moderate amounts, usually with meals.<ref>Template:Cite web</ref><ref>Template:Cite web</ref> Olive oil is the principal source of fat and has been studied as a potential health factor for reducing all-cause mortality and the risk of chronic diseases.<ref>Template:Cite journal</ref>

The Mediterranean diet is associated with a reduction in all-cause mortality in observational studies.<ref name="AACAHA2019">Template:Cite journal</ref><ref>Template:Cite journal</ref> A 2017 review provided evidence that the Mediterranean diet lowers the risk of heart disease and early death;<ref name=Dinu2017>Template:Cite journal</ref> it may also help with weight loss in obese people.<ref name="pallaz">Template:Cite journal</ref> 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.<ref name="USDietaryGuidelines2015">Template:Cite web</ref> It is also recognized by the World Health Organization as a healthy eating pattern.<ref name=":0">Template:Cite web</ref>

Mediterranean cuisine and its associated traditions and practices were recognized as an Intangible Cultural Heritage of Humanity by UNESCO in 2010 under the name "Mediterranean Diet".Template:Efn<ref>Template:Cite web</ref> The Mediterranean diet is sometimes broadened to include particular lifestyle habits, social behaviors, and cultural values closely associated with certain Mediterranean countries,<ref>Template:Cite journal</ref> such as simple but varied cooking methods,<ref>Template:Cite journal</ref> communal meals, post-lunch naps, and regular physical activity.<ref name=":0" /><ref>Template:Cite web</ref>

Health effects

A 2017 review found evidence that practice of a Mediterranean diet could lead to reduced risk of cardiovascular diseases, overall cancer incidence, neurodegenerative diseases, diabetes, and early death.<ref name=Dinu2017/> 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.<ref name="martinez-lacoba2018">Template:Cite journal</ref> A 2016 review found similar weight loss as other diets.<ref>Template:Cite journal</ref> 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 existing cardiovascular disease.<ref name="ReferenceA">Template:Cite journal</ref>

The United States 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.<ref name="USDietaryGuidelines2015" /> In the 2020s, research on the Mediterranean diet indicates that it may contribute to health.<ref>Template:Cite journal</ref>

Cardiovascular disease

The Mediterranean diet is included among dietary patterns that may reduce the risk of cardiovascular diseases.<ref name=pallaz/> A 2013 Cochrane review found limited evidence that a Mediterranean diet favorably affects cardiovascular risk factors.<ref name="ReferenceA"/> 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.<ref>Template:Cite journal</ref> 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.<ref name="Huedo2016">Template:Cite journal</ref> These reviews insisted upon the need for further standardized research,<ref name="pmid26483006">Template:Cite journal</ref> stating that the evidence for possible prevention of cardiovascular disease by the diet was "limited and highly variable".<ref name="pmid27509006">Template:Cite journal</ref> 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.<ref name=Dinu2017/><ref name="Gay2016">Template:Cite journal</ref> A Mediterranean diet is recommended as a means of lowering Apolipoprotein B.<ref name="pmid327821191">Template:Cite journal</ref>

The Mediterranean diet is low in saturated fat with high amounts of monounsaturated fat and dietary fiber. One possible factor is the potential health effects of olive oil in the Mediterranean diet. Olive oil contains monounsaturated fats, most notably oleic acid, which is under clinical research for its potential health benefits.<ref name=BucklandGonzalez2015>Template:Cite journal</ref> The European Food Safety Authority Panel on Dietetic Products, Nutrition and Allergies approved health claims on olive oil, for protection by its polyphenols against oxidation of blood lipids<ref name=EFSApolyphenols2011>Template:Cite journal</ref> and for the contribution to the maintenance of normal blood LDL-cholesterol levels by replacing saturated fats in the diet with oleic acid<ref name=EFSAoleicacid2011>Template:Cite journal</ref> (Commission Regulation (EU) 432/2012 of 16 May 2012).<ref name=OfficialJournalEuropeanUnion2012>Template:Cite web</ref> A 2014 meta-analysis concluded that an elevated consumption of olive oil is associated with reduced risk of all-cause mortality, cardiovascular events and stroke, while monounsaturated fatty acids of mixed animal and plant origin showed no significant effects.<ref name=SchwingshacklHoffmann2014>Template:Cite journal</ref> The American Heart Association discussed the Mediterranean diet as a healthy dietary pattern that may reduce the risk of cardiovascular diseases.<ref name="AHA2016">Template:Cite journal</ref>

A 2023 review found evidence for a reduction of mortality and cardiovascular disease risk in women on a Mediterranean-type diet.<ref name="HRT-20230314">Template:Cite journal</ref>

Diabetes

In 2014, two meta-analyses found that the Mediterranean diet was associated with a decreased risk of type 2 diabetes,<ref>Template:Cite journal</ref><ref>Template:Cite journal</ref> findings similar to those of a 2017 review.<ref name=Dinu2017/> The American Diabetes Association and a 2019 review indicated that the Mediterranean diet is a healthy dietary pattern that may reduce the risk of diabetes.<ref name="ADA2019">Template:Cite journal</ref><ref>Template:Cite web</ref>

Cancer

A meta-analysis in 2008 found that strictly following the Mediterranean diet was correlated with a decreased risk of dying from cancer by 6%.<ref name="pmid18786971">Template:Cite journal</ref> Another 2014 review found that adherence to the Mediterranean diet was associated with a decreased risk of death from cancer.<ref>Template:Cite journal</ref> A 2017 review found a decreased rate of cancer, although evidence was weak.<ref name="Dinu2017"/> An updated review in 2021 found that the Mediterranean diet is associated with a 13% lower risk of cancer mortality in the general population.<ref>Template:Cite journal</ref>

Weight loss in obesity

Overweight adults who adopt Mediterranean diets may lose weight by consuming fewer calories.<ref>Template:Cite journal</ref><ref>Template:Cite journal</ref><ref>Template:Cite journal</ref> A 2019 review found that the Mediterranean diet may help obese people lower the quantity and improve the nutritional quality of food intake, with an overall effect of possibly losing body weight.<ref name=pallaz/>

Cognitive ability

A 2016 systematic review found a relation between greater adherence to a Mediterranean diet and better cognitive performance; it is unclear if the relationship is causal.<ref>Template:Cite journal</ref>

According to a 2013 systematic review, greater adherence to a Mediterranean diet is correlated with a lower risk of Alzheimer's disease and slower cognitive decline.<ref>Template:Cite journal</ref> Another 2013 systematic review reached similar conclusions, and also found a negative association with the risk of progressing from mild cognitive impairment to Alzheimer's, but acknowledged that only a small number of studies had been done on the topic.<ref>Template:Cite journal</ref>

Major depressive disorder

Observational studies have found a correlation between adherence to the Mediterranean diet and a lower risk of depression but have not proven that a Mediterranean diet lowers the risk of depression.<ref>Template:Cite journal</ref><ref>Template:Cite journal</ref>

Gluten

As the Mediterranean diet usually includes products containing gluten, such as pasta and bread, increasing use of the diet may have contributed to the growing rate of gluten-related disorders.<ref name="VoltaCaioQuestionsQuotation">Template:Cite journal</ref>

Dietary components

The Mediterranean diet food pyramid, summarizing the pattern of eating associated with this diet

There are variations of the "Mediterranean diets" in different countries and among the individual populations of the Mediterranean basin, due to ethnic, cultural, economic and religious diversities.<ref name="bmc">Template:Cite journal</ref> The "Mediterranean diet" as defined by dietitians generally includes the following components,<ref name=pallaz/> which are not typical of diets in the Mediterranean Basin:<ref name=LinAronson2015>Template:Cite journal</ref><ref name="Willett_Defines_Med_Diet">Template:Cite journal</ref>

• High intakes of olive oil (as the principal source of fat), and a plant-based diet: vegetables (including leafy green vegetables, onions, garlic, tomatoes, and peppers), fresh fruits (consumed as desserts or snacks), cereals (mostly whole grains), nuts, and legumes.
• Moderate intakes of fish and other seafood, poultry, eggs, dairy products (primarily cheese and yogurt), and red wine.
• Low intakes of red meat, processed meat, refined carbohydrates, and sweets.

These proportions are sometimes represented in the Mediterranean Diet Pyramid. In a diet with roughly this composition, the fat content accounts for 25% to 35% of the total intake of calories, while the amount of saturated fat is, at most, 8% of the calorie content.<ref name="Willett_Defines_Med_Diet" />

Some cuisines of the Mediterranean region are not fully consistent with Mediterranean diet guidelines. For instance, olive oil is not the staple fat in the cuisines of all countries which border the Mediterranean: in northern and central Italy, lard and butter are commonly used in cooking, and olive oil is reserved for dressing salads and cooked vegetables;<ref name="Alberini">Massimo Alberini, Giorgio Mistretta, Guida all'Italia gastronomica, Touring Club Italiano, 1984</ref> in both North Africa and the Middle East, sheep's tail fat and rendered butter (samna) are traditional staple fats.<ref name="Tapper">Template:Cite book</ref>

Comparison of dietary recommendations for three Mediterranean diet plans

Foods	Oldway's Preservation and Trust (2009)<ref>Template:Cite web</ref>	Mediterranean Diet Foundation (2001)<ref>Template:Cite journal</ref>	Greek Dietary Guidelines (1999)<ref>Food and Agriculture Organization of the United Nations, "Food-based dietary guidelines—Greece" [1]</ref><ref>Template:Cite journal</ref>
Olive oil	Every meal	Every meal	Main added lipid
Vegetables	Every meal	≥2 servings every meal	6 serv./day
Fruits	Every meal	1–2 serv. every meal	3 serv./day
Bread/cereals	Every meal	1–2 serv. every meal	8 serv./day
Legumes	Every meal	≥2 serv./week	3-4 serv./week
Nuts	Every meal	1–2 serv./day	3–4 serv./week
Fish/seafood	≥2 serv./week	≥2 serv./week	5–6 serv./week
Eggs	Moderate portions, daily to weekly	2–4 serv./week	3 serv./week
Poultry	Moderate portions, daily to weekly	2 serv./week	4 serv./week
Dairy products	Moderate portions, daily to weekly	2 serv./day	2 serv./day
Red meat	Less often	<2 serv./week	4 serv./month
Sweets	Less often	<2 serv./week	3 serv./week
Red wine	In moderation	In moderation	Daily, in moderation
Template:Small

Environmental effects

Template:See also Consuming a Mediterranean diet or plant-based diet may contribute to improving environmental and agricultural sustainability,<ref>Template:Cite journal</ref><ref>Template:Cite journal</ref> possibly due to lower use of dairy products, ruminant meat, and ultra-processed foods.<ref name="nbcnews.com">Template:Cite web</ref>Template:Better source The environmental impact and amount of energy needed to feed livestock exceeds its nutritional value.<ref>Template:Cite news</ref><ref>Template:Cite web</ref> In a 2014 lifecycle analysis of greenhouse gas emissions, researchers found that a Mediterranean-like diet may reduce food production emissions below those of an omnivorous diet for 2050, with a per capita reduction of 30%.<ref>Template:Cite journal</ref><ref>Template:Cite journal</ref>

History and research

Elements of the Mediterranean diet have been traced to several ancient cultures in the region, particularly the Greeks and Romans, using olive oil, seafood, bread, and wine.<ref name=keys/> The Mediterranean diet as a concept was first publicized in 1975 by American biologist Ancel Keys and chemist Margaret Keys, a husband-and-wife team.<ref name="keys">Template:Cite book</ref> The Keys were the first to draw a correlation between cardiovascular disease and diet, based on studies in the 1950s in southern Italy.<ref name=keys/>

Objective data showing possible benefits of the Mediterranean diet originated from epidemiological studies in southern Italy and Crete; these were confirmed later by the Seven Countries Study directed by Keys and published in 1970,<ref>Template:Cite journal</ref><ref name="guard">Template:Cite news</ref> which was followed by a book-length report in 1980.<ref>Template:Cite book</ref> A 25-year follow up study published in 1996 determined that populations that had adopted a "Mediterranean diet"—defined as incorporating olive oil, bread, pasta, vegetables, herbs and seafood, with moderate consumption of meat—presented low levels of blood cholesterol and reduced incidence of coronary heart disease.<ref name=guard/><ref name="7cs">Template:Cite journal</ref>

The Mediterranean diet was further studied in the 1990s by Walter Willett and colleagues of the Harvard University School of Public Health.<ref> Template:Cite news </ref><ref>Template:Cite journal</ref><ref>Template:Cite journal</ref><ref>Template:Cite journal</ref> The Mediterranean diet is based on a paradox: although people living in Mediterranean countries tend to consume relatively high amounts of fat, they generally have lower incidence of cardiovascular disease than those living in countries with similar levels of fat consumption, such as the United States; a parallel phenomenon is known as the French paradox.<ref name="Paradoxes">Template:Cite journal</ref>

Since about 2016, the American Heart Association and American Diabetes Association have recommended the Mediterranean diet as a dietary pattern that may reduce the risk of cardiovascular diseases and type 2 diabetes.<ref name="AHA2016" /><ref name="ADA2019" /><ref name="ADA2018">Template:Cite journal</ref> The National Health Service also recommends a Mediterranean diet to reduce cardiovascular disease risk.<ref>Template:Cite web</ref>

In 2018, clinical research showed favorable outcomes for using the Mediterranean diet to lower the risk of metabolic syndrome.<ref name="villani">Template:Cite journal</ref>

Researchers frequently use questionnaires such as the MEDAS questionnaire (Mediterranean diet adherence screener) to monitor how closely someone is adhering to a Mediterranean-style diet, and can also be used by individuals monitoring their own diet.<ref>Template:Cite journal</ref><ref>Template:Cite web</ref>

See also

• Cretan cuisine
• Health effects of wine
• Ikaria Study
• List of diets
• Mediterranean cuisine
• Mediterranean Diet Foundation
• Sustainable diet

Further reading

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