Mediterranean diet

• 1. Introduction

  ›

  The Mediterranean diet is the most well-known and researched dietary pattern in the world. It did not begin as a formal diet at all. In 1975, the American biologist Ancel Keys and the chemist Margaret Keys, a husband and wife, first proposed it as a concept. They drew on the eating habits of Greece, Italy, the Mediterranean coasts of France and Spain, and the Levant. Those habits had been observed in the late 1950s and early 1960s, decades before the label existed.

  What turns a regional way of eating into a pattern doctors recommend worldwide? Part of the answer lies in the specific foods on the plate. Another part lies in a paradox about fat and heart disease that puzzled researchers for decades. The rest lies in a body of clinical review that is still being revised today.

• 2. What The Diet Actually Contains

  ›

  Olive oil serves as the principal source of fat in this pattern. The diet emphasizes plant-based foods: unprocessed cereals, legumes, vegetables, and fresh fruits, eaten as desserts or snacks. Fish and dairy, mostly cheese and yogurt, appear in moderate amounts. Red meat, refined grains, and sugar are kept low, and wine, typically red, is allowed in low to moderate amounts with meals.

  This eating pattern is distinct from Mediterranean cuisine itself, which spans the diverse culinary traditions of every Mediterranean country. It is also distinct from the Atlantic diet of northwestern Spain and Portugal, even though the two share some characteristics. Dietitians represent the proportions in what is called the Mediterranean Diet Pyramid. In a diet built to this pyramid, fat makes up 25-35% of total calories, and saturated fat accounts for at most 8%. Not every cuisine within the Mediterranean basin follows this pattern as closely as the name suggests.

• 3. Two Scientists And A Paradox

  ›

  Ancel Keys drew the first correlation between cardiovascular disease and diet from studies he conducted in southern Italy during the 1950s. That early work grew into the Seven Countries Study, which Keys directed and published in 1970, followed by a book-length report in 1980. Elements of this way of eating trace back further still, to the ancient Greeks and Romans, who relied on olive oil, seafood, bread, and wine.

  A follow-up study published in 1996 covered 25 years of data. It found that populations eating olive oil, bread, pasta, vegetables, herbs, and seafood, with only moderate meat, had lower blood cholesterol. They also had less coronary heart disease. Walter Willett and colleagues at the Harvard University School of Public Health studied the diet further during the 1990s. Their work sits alongside a puzzle. People in Mediterranean countries eat relatively high amounts of fat. Yet they suffer less cardiovascular disease than countries with similar fat intake, such as the United States. Researchers call this pattern the French paradox. That puzzle set off decades of clinical review into whether the diet truly protects the heart.

• 4. The Heart Evidence

  ›

  On the 16th of May 2012, the European Food Safety Authority approved health claims for olive oil under Commission Regulation 432/2012. The claims credited its polyphenols with protecting blood lipids from oxidation. They also credited oleic acid with helping maintain normal LDL cholesterol when it replaces saturated fat in the diet. Researchers separately describe the overall Mediterranean diet as low in saturated fat and high in monounsaturated fat and dietary fiber. Olive oil's oleic acid remains under clinical study for its own health effects. A 2014 meta-analysis linked higher olive oil consumption to reduced risk of all-cause mortality, cardiovascular events, and stroke. Monounsaturated fats from mixed animal and plant sources, by contrast, showed no significant effect.

  The United States built a Healthy Mediterranean-Style Eating Pattern into its 2015-2020 national dietary guidelines. That pattern grew out of the government's own Healthy U.S.-Style Eating Pattern but recommends more fruit and seafood and less dairy. A 2020 review of Mediterranean diet research indicated that it may optimize cardiovascular health.

  A 2013 Cochrane review found only limited evidence that the diet favorably affects cardiovascular risk factors. That same year, a separate meta-analysis compared it against vegan, vegetarian, low-glycemic-index, low-carbohydrate, high-fiber, and high-protein diets. It concluded that Mediterranean, low-carbohydrate, low-glycemic-index, and high-protein diets each improved markers of cardiovascular and diabetes risk. Evidence for vegetarian diets affecting glycemic control and lipid levels, apart from weight loss, remained limited. In 2016, researchers recommended the diet as a way to lower apolipoprotein B.

  More cautious voices emerged in 2016, questioning the quality of earlier systematic reviews on the diet's cardiovascular effects. These critics called for more standardized research, noting that the existing evidence varied widely in quality and offered limited certainty about clinical outcomes. Other reviews published in 2016 and 2017 still concluded that the diet could improve cardiovascular risk factors, including lowering the risk of hypertension. A 2019 Cochrane review then found genuine uncertainty about the diet's effects on cardiovascular disease, in people both with and without existing heart disease. It described the benefits as modest and the supporting evidence as low to moderate quality. A 2023 review found evidence for reduced mortality and cardiovascular disease risk among women following the diet. A 2024 meta-analysis linked adherence to the diet with reduced cardiovascular disease risk. That same body of research would go on to ask whether the diet's benefits reached beyond the heart, into cancer risk, diabetes, and weight.

• 5. Beyond The Heart

  ›

  A 2017 review found that following the Mediterranean diet was linked to reduced risk across several fronts at once. These included cardiovascular disease, cancer, neurodegenerative disease, diabetes, and early death. A 2018 review went further, suggesting the diet could improve overall health status and lower the risk of non-infectious diseases. It also suggested the diet could reduce both personal living costs and national healthcare spending. A 2016 review found the diet produced weight loss similar to other diets.

  Two separate meta-analyses in 2014 found the Mediterranean diet associated with a decreased risk of type 2 diabetes, a finding a 2017 review echoed.

  A 2008 meta-analysis found that strict adherence to the diet correlated with a 6% lower risk of dying from cancer. A 2014 review reached a similar conclusion, linking adherence to a decreased risk of cancer death. A 2017 review found a decreased cancer rate too, though it described the evidence as weak. An updated 2021 review found the diet associated with a 13% lower risk of cancer mortality in the general population.

  A 2019 review found the diet could help obese people reduce the quantity and improve the nutritional quality of what they eat. The overall effect was possibly losing body weight. More generally, overweight adults who adopt the Mediterranean diet may lose weight simply by consuming fewer calories. The research on cancer, diabetes, and weight loss says nothing yet about the diet's relationship with the brain, mood, or gluten.

• 6. Mind Mood And Bread

  ›

  A 2016 systematic review found that people who adhered more closely to the Mediterranean diet tended to perform better on cognitive tests. It remained unclear whether the relationship was causal. A 2013 systematic review went further, linking greater adherence to a lower risk of Alzheimer's disease and slower cognitive decline. A second systematic review from 2013 reached similar conclusions. It also found a negative association between the diet and the risk of progressing from mild cognitive impairment to Alzheimer's. The review acknowledged that only a small number of studies existed on the topic.

  Pasta and bread supply much of the gluten in a typical Mediterranean diet. The diet's growing popularity may have contributed to a rising rate of gluten-related disorders. Observational studies have also found a correlation between adherence to the diet and a lower risk of depression. They have not proven that the diet actually lowers that risk. These open questions about the brain and mood have not stopped major health bodies from formally endorsing the diet.

• 7. Official Recognition

  ›

  The Dietary Guidelines for Americans named the Mediterranean diet as one of three healthy eating patterns, alongside the DASH diet and a vegetarian diet. The World Health Organization also recognizes it as a healthy eating pattern. In 2010, UNESCO went further still, recognizing Mediterranean cuisine and its associated traditions as an Intangible Cultural Heritage of Humanity, under the name Mediterranean Diet.

  Post-lunch naps, communal meals, simple but varied cooking methods, and regular physical activity round out a broader version of this diet. Since about 2016, the American Heart Association and American Diabetes Association have recommended the diet as a pattern that may reduce cardiovascular disease risk. They also credit it with possibly reducing the risk of type 2 diabetes. The National Health Service also recommends the diet to reduce cardiovascular disease risk.

  In 2018, clinical research showed favorable outcomes from using the Mediterranean diet to lower the risk of metabolic syndrome. Researchers frequently track adherence with tools such as the MEDAS questionnaire, the Mediterranean diet adherence screener. Individuals can also use it to monitor their own eating habits. None of these endorsements guarantee that every Mediterranean table actually looks like the diet on paper.

• 8. The Diet In Practice

  ›

  In northern and central Italy, cooks commonly reach for lard and butter rather than olive oil, saving olive oil for dressing salads and cooked vegetables. In North Africa and the Middle East, traditional staple fats instead include sheep's tail fat and a rendered butter called samna. The dietitian-defined version of the Mediterranean diet is not actually typical of most eating across the Mediterranean basin. The region's countries differ by ethnicity, culture, economics, and religion.

  A 2014 lifecycle analysis of greenhouse gas emissions found a Mediterranean-like diet could cut food production emissions below those of an omnivorous diet by 2050. The projected reduction came to 30% per capita. Raising livestock demands more energy than the food ultimately returns in nutritional value. Choosing a Mediterranean or plant-based diet may also improve environmental and agricultural sustainability, largely because it relies less on dairy, ruminant meat, and ultra-processed foods. That 2050 projection remains just that, a projection, resting on how closely future kitchens actually follow this pattern.