What is the Mediterranean diet?
The term "Mediterranean diet" is used today to describe the traditional eating habits of countries bordering the Mediterranean Sea, primarily Greece and southern Italy. Nonetheless, it should be understood as more than a strict reference to the preferences exhibited by these groups in their daily food choices, since the original meaning of the worddiaitain Greek refers to more than just food or diet Choice, rather, refers to a certain "way of life", which is more in line with the modern concept of "lifestyle".
History and background
Determining the origins of this diet is relatively difficult, but it is likely that it developed alongside populations living in the Mediterranean basin since the emergence of civilization. Throughout history, the Mediterranean diet has incorporated some of the habits brought by the conquerors while keeping most of the previous local traditions alive and functional. The roots of the Mediterranean diet can be seen in ancient societies that were part of the Fertile Crescent - the geographical area of the Near East between the eastern end of the Mediterranean Sea and the Persian Gulf that includes Mesopotamia, Canaan and, according to some, northern Egypt .
Since the most ancient times, food has spread between the countries and cultures of the Mediterranean basin. Hieroglyphic records mention the export of wine and olives from Canaan to ancient Egypt. The city-state of Athens is symbolized by the olive tree, and the ancient Greeks left the olive branch to humans as a symbol of peace. The influence of Greek food was brought to the Near East after Alexander the Great conquered the territory in the 4th century BC. As a plant-based diet, the Mediterranean diet has been subject to successive influences as successive plant species were imported from other geographical regions of the world and adapted in the Mediterranean basin.
Where is the Mediterranean Sea?
Mediterranean diet in English is mediterranean diet. The Mediterranean Sea, the intercontinental sea that separates Europe and Africa from the Atlantic Ocean in the west to Asia in the east. It is often called the incubator of Western civilization. This ancient "sea between the lands" lies in a deep, elongated, almost landlocked, irregular depression between latitudes 30° and 46° N, longitude 5°50′ W and 36° E. The countries surrounding the Mediterranean Sea in clockwise order are Spain, France, Monaco, Italy, Slovenia, Croatia, Bosnia and Herzegovina, Montenegro, Albania, Greece, Turkey, Syria, Lebanon, Israel, Egypt, Libya, Tunisia, Algeria, and Morocco; Malta And Cyprus is an island country on the sea.
Mediterranean food culture
Traditional food habits seen in the geographical areas surrounding the Mediterranean Sea, although they vary according to certain food choices and cooking practices of each country and culture, share a common set of basic characteristics. Specific dietary dimensions of the Mediterranean lifestyle include plant-based cuisine using vegetables, fruits, grains, nuts and legumes, much of which is cooked with the addition of large amounts of olive oil, and moderate use of fish, seafood or dairy products, and meat and limited alcohol intake (mainly red wine). This unique dietary pattern, the result of a complex, millennia-long interaction between the natural food resources available in the Mediterranean environment and the human elements that historically inhabited the Mediterranean basin, has acquired a new value in the last century and become a Precious food. Medical Tools for the Contemporary World.
At the moment when the health benefits associated with the Mediterranean diet are widely recognized, its paradoxical fate is that it risks disappearing from its native territory. Globalization, the introduction of Western habits, changes in lifestyles and the unique environment of modern civilization have brought a heavy price to the traditional Mediterranean diet. Meanwhile, the United Nations Educational, Scientific and Cultural Organization (UNESCO) considers the Mediterranean diet an “intangible cultural heritage under urgent protection” when international guidelines include it among recommended healthy dietary patterns. Given this contradictory position between universal medical acceptance and cultural genocide.
Food patterns along the Mediterranean coast are heavily influenced by the three main monotheistic faiths that have found success in the region: Judaism, Christianity, and Islam. These religions also adopted, sustained and held sacred some of the fundamental components of the Mediterranean way of life.
Mediterranean Diet Principles
The Mediterranean diet is not a unique diet as the word "diet" refers to today. Each region of the Mediterranean basin has its own recipes, preferences and restrictions. The term "Mediterranean diet" is best understood as a specific "eating pattern" with a specific set of interrelated characteristics. Descriptions that include only some foods present in popular culture, while ignoring the absence of other traditional foods or allowing the addition of foods belonging to other food cultures and patterns, should not be accepted as a suitable version of the Mediterranean diet. A true Mediterranean dietary pattern should be viewed as a "whole", including all of its characteristics, not just some of them.
First of all, olive oil plays a central role in the cooking process and is therefore a major source of dietary fat. Cheese is available in limited quantities, usually in salads. Meat, milk, and eggs are low in percentage and quantity, and processed meats and sweets are almost non-existent. Therefore, the Mediterranean diet actually represents the only traditional dietary pattern that consumes essentially low amounts of saturated and trans fats.
Second, olive oil consumption is associated with higher vegetable intake, such as salad preparations, and equally high legume intake in foods prepared with heat, meaning that the Mediterranean diet is essentially a plant-based diet. based dietary pattern. Other key components of the Mediterranean diet are whole grains, nuts, fresh fruits and moderate fish intake. However, some differences in food intake do exist between countries. For example, total fat consumption differs significantly in Greece, which reaches 40% or more of total daily caloric intake, while in Italy fat intake is limited to 30% of daily caloric intake.
A constant feature between the different regions of the Mediterranean basin is a high ratio of monounsaturated to saturated fat, far exceeding similar ratios in Northern Europe or North America. Countries also differ in their choice of other food sources. The Italian diet is characterized by high consumption of pasta, while the Spanish variant of the Mediterranean diet is characterized by high consumption of fish and seafood.
A review of the literature that took into account differences between countries on the Mediterranean diet found that from one case to another it included three to nine servings of vegetables, half to two servings of fruit, one to 13 servings of grains, and as many as eight of olive oil. However, the variation in nutrient content appears to be smaller than the variation in serving size, as in most cases the selections from different food groups complement each other to provide the overall single profile described above.
Mediterranean Diet Pyramid
Because of this geographical variation in food choices, current guidelines consider different combinations of food groups to form the Mediterranean dietary pattern. There are three main variations of the food pyramid to describe the Mediterranean diet:
- Oldway's Preservation and Exchange Trust pyramid,
- The traditional Mediterranean diet of the Greek nutrition guidelines,
- The Mediterranean Diet Foundation pyramid.
Some of these models retain characteristics of traditional eating habits, while others have been modified in time to better suit today's food supply availability, nutritional needs, and eating habits.
Geographical origins of plant species in the Mediterranean diet
Native plants of the Mediterranean region | Olives, borage, beets, capers, lupins, asparagus, watercress, mallow, thistle, grapes, beet, tiger nut, parsley, cumin, coriander, fennel, oregano, rosemary , sage, lemon balm, coriander, fenugreek, bay leaf, saffron, mushrooms |
Plants from other parts of Asia | Rice, buckwheat, wheat, barley, chickpeas, soybeans, lentils, beans, onions, garlic, leeks, cabbage, broccoli, cauliflower, radish, spinach, cucumber, yams, arugula, banana, coconut, Figs, apples, papayas, pears, mangoes, plums, cherries, raspberries, lemons, cucumbers, kiwis, almonds, hazelnuts, walnuts, chestnuts, marjoram, tarragon, pepper, saffron, turmeric, cloves, ginger |
Plants native to Africa | Millet, sorghum, artichoke, okra, watermelon, melon |
Plants native to the Americas | Corn, other beans, peanuts, tomatoes, peppers, eggplants, pumpkins, zucchini, potatoes, sweet potatoes, prickly pear, cashews, sunflower seeds, avocado, coffee, chocolate, chili peppers, allspice, pink pepper |
Discovery and recognition of the health benefits of the Mediterranean diet
The man who discovered the health benefits of a Mediterranean lifestyle and coined the term "Mediterranean diet" was Ancel Keys. An expert in animal biology and agriculture, Case studied the effects of starvation on the human body at the end of World War II and sought nutritional strategies to restore health after starvation. He was surprised to find that countries where hunger led people to avoid eating high-fat, high-calorie foods had significant reductions in fatal heart disease, but not when those countries recovered from war and food changed again. . At the same time, Reason was also aware of the prevalence of heart disease among the wealthy middle class in the United States, so he began to suspect that diet affected health, especially the risk of heart disease.
In 1951, while on a year-long sabbatical from his job in Oxford, he heard that the incidence of heart disease was very low in southern Italy. Keyes went to Naples and opened a portable laboratory there. He quickly confirmed the stories he had heard about the low incidence of coronary ischemic disease, and he also noticed that most locals exhibited low cholesterol levels. Case conducted similar reviews in other European and African countries, gradually finding that diets rich in saturated fat were associated with elevated serum cholesterol levels and a higher risk of coronary heart disease.
When Ancel Keys first proposed the theory that "diet is a form of heart disease" at a World Health Organization meeting in 1955, he was met with skepticism, and despite his worldwide fame, he was Further evidence was presented at the invitation of scientist Sir George Pickering. . They chose to study smoking, diet, physical activity, weight, blood pressure, heart rate, lung capacity, blood cholesterol and electrocardiogram readings in seven groups of men. nation. . Former Yugoslavia, Italy, Greece, Finland, Netherlands, United States and Japan. Yugoslavia was chosen because it offers the opportunity to count people who own both food on the coast and along the coast of the country. Italy was the first country Ancel Keys found (although not mentioned) to be associated with a reduction in heart disease with a Mediterranean lifestyle. Greece has the opportunity to evaluate people who are high in fat but low in saturated fat, since the main source of fat is olive oil, which is rich in monounsaturated fatty acids. Finland has a very healthy population, but has high rates of heart disease and obesity. There is an opportunity in Japan to count people who eat less fat.
Finland, on the other hand, had the highest percentage, and the United States was the second. A direct comparison between Crete and Finland showed that the rate of coronary heart disease in these was almost 100 times higher (0.1% compared to Finland). Dietary calories from total fat account for 9-40% of total daily intake, but because Greece is one of the countries with the highest fat consumption, this figure does not always correspond with heart disease rates. Calories from saturated fat range from 3% to 22%. The relationship between heart attack rates and saturated fat is very strong.
Ancel Keys then realized that dietary habits inherited among traditional Mediterranean populations, especially Greece and southern Italy, were associated with a reduced risk of cardiovascular disease. He coined these eating habits under the term "Mediterranean Diet" and co-authored two books on the subject: Eat Well and Stay Healthy and How to Eat Well and Stay Healthy the Mediterranean Way. He adopted the advice of his own Mediterranean dietary pattern and died in 2004 at the age of 100, his efforts and research simultaneously gaining worldwide recognition and respect.
Further evidence of the health benefits of the Mediterranean diet
Despite studies showing a link between eating habits and heart disease, the concept of a "Mediterranean diet" was shelved until the early 1990s. The Lyon Diet Heart Study is a randomized trial designed to evaluate the effects of a modern French modified Mediterranean diet in patients with a history of heart disease. In a large cohort study, a 2 percentage point increase in the Mediterranean diet was associated with a significant 33% reduction in cancer risk. Two other studies from the Spanish group and the international HALE project confirmed that strict adherence to the Mediterranean diet reduces the number of cardiovascular events as well as risk factors. Reductions in cancer activity have also been observed in secondary prevention studies.
The study recruited 7,447 participants with no evidence of cancer in a randomized trial comparing a low-fat diet, a Mediterranean diet with olive oil, and a Mediterranean diet with nuts. While all three diets reduced cancer risk as a whole, the Mediterranean diet showed a 30% lower risk of heart disease and a 40% lower risk of stroke. Further analysis showed that the Mediterranean diet can reduce the expression of proatherogenic genes and alter risk markers such as waist-to-hip ratio, lipids, lipoproteins, and oxidative/inflammatory biomarkers. The authors also re-evaluated, not including those who did not, and still found that olive oil and nut supplements were associated with reductions of 31% and 28%, respectively, compared to a low intake fat.
Trials have extended the Mediterranean diet's cardiovascular benefits beyond the Mediterranean region. A randomized Indian trial used an "Indo-Mediterranean" diet rich in whole grains, fruits, vegetables, walnuts, and mustard or soybean oil, versus the NCEP Step I diet. The Indo-Mediterranean group saw a 60% lower cardiovascular mortality and 50% lower non-fatal heart attacks. A UK study of 23,902 participants found Mediterranean diet adherence associated with lower cardiovascular events over 12.2 years, though less strong an effect than PREDIMED. This may partly reflect imperfect transfer of Mediterranean habits to British diets. Two US cohort studies also found significantly fewer cardiovascular events among Americans adhering to the Mediterranean diet.
Successive meta-analyzes of previous cohort studies in the upper levels of the evidence pyramid acknowledge an association between the Mediterranean diet and reduced cardiovascular morbidity and mortality. A meta-analysis of randomized controlled trials comparing the Mediterranean diet to a low-fat diet found significant effects on body weight, BMI, blood pressure, fasting plasma glucose, total cholesterol, and high-sensitivity C-reactive protein in low-density lipoprotein. There were no statistically significant differences in low-density lipoprotein (LDL)-cholesterol and high-density lipoprotein (HDL)-cholesterol levels. Another meta-analysis of randomized controlled trials investigating the effect of a Mediterranean food pattern on primary cardiovascular disease prevention showed benefits on total and LDL cholesterol levels.
Separate studies confirm that adherence to the Mediterranean diet is associated with favorable evolution of abdominal obesity, weight changes, and reduced incidence of overweight and obesity. Systematic reviews and meta-analyzes considering several dietary patterns confirmed the protective effect of the Mediterranean diet on type 2 diabetes development. Two prospective clinical trials specifically designed to evaluate Mediterranean diet benefits in preventing type 2 diabetes found greater compliance associated with lower risk of developing diabetes. Nonetheless, several meta-analyzes, including clinical trials in patients with established type 2 diabetes, have also shown Mediterranean diet benefits on glycemic control as assessed by plasma glucose and glycated hemoglobin evolution.
Additional analyzes examined benefits for other diseases. The first evidence linking the Mediterranean diet to reduced risk of cancer and death came from the second phase of the Lyon Diet Heart Study. A recent meta-analysis found that adherence to a Mediterranean diet was inversely associated with overall cancer risk and with the risk of specific types of cancer. Another review also found that the diet reduced the risk of all liver cancers except pancreatic cancer.
There is evidence that the Mediterranean diet may be beneficial in non-alcoholic fatty liver disease. In addition, following a Mediterranean diet can also prevent neurodegenerative diseases. European and American studies show that better adherence to this diet reduces the risk of cognitive decline and Alzheimer's disease. A large study involving 131,368 participants in the US Health Professionals and Nurses' Health Study found that greater adherence to the Mediterranean diet had a 25 percent lower risk of Parkinson's disease.
In a 12-month longitudinal study of healthy workers in Chile, a Mediterranean diet implemented at work improved waist circumference, HDL cholesterol, and blood pressure and reduced the risk of metabolic syndrome by 35%. Another two-year study of overweight workers in Israel found significant reductions in body weight, triglycerides, and total cholesterol in individuals randomly assigned to a Mediterranean diet. In a study group of US firefighters at high risk of heart disease, adherence to a Mediterranean diet was associated with significant improvements in body weight, LDL cholesterol, and HDL cholesterol, and reductions in total body weight and body fat.
A cross-sectional study in the PREDIMED trial found that increasing polyphenol intake was associated with a reduction in risk. Other data from the PREDIMED trial also show benefits from using olive oil in the diet; an increase of 10 grams of extra virgin olive oil per day was associated with a 10% reduction in non-cardiovascular events and a 7% reduction in cardiovascular events. ; Cancer and disease are not included in this article because they are considered too relevant. The polyphenols and phytochemicals in olive oil have an antioxidant effect, reducing the oxidation of unsaturated fatty acids in its components.
A systematic review of studies attempting to examine the relationship between the Mediterranean diet and various disease manifestations found evidence to support this relationship, although few research articles were presented. In addition to the anti-inflammatory effects of monounsaturated fatty acids found in virgin olive oil, phenolic derivatives found in olive oil, such as tyrosol, hydroxytyrosol, bicycloalkenyl ethers, and lignans, appear to be involved in cell cycle signaling. Related, terpenes such as oleanolic acid. Maslinic acid and maslinic acid have regulatory effects on genes involved in circadian rhythms in animal models.