Mediterranean diet as the basis of a long life

It is believed that the term “Mediterranean diet” (MD) was introduced by Ancel Keys in the 1960s to define a diet rich in vegetable fats and almost free of saturated fats, which is typical for Greece and Southern Italy. The reason, which sparked an acute interest in scientists, was that the research conducted in seven countries throughout 25 years showed a reduced risk of coronary heart disease in these regions compared with Northern Europe and the United States. Since then, more than half a century has passed, and the study of the MD spurred new diverse definitions of this dietary phenomenon based on different principles, but one way or another, at the heart of all definitions there remained a relatively unchanged set of foods, more precisely, food substances as components of the MD.

Anyway, any description of the MD will include the following advice: high consumption of extra virgin olive oil (cold pressed), vegetables, including leafy vegetables, fruit, cereals, nuts and legumes, moderate consumption of fish and meat, dairy and red wine, little intake of eggs and sweets. As we see, almost all core foods are included in the MD, however, vegetable oil, fruit, vegetables and cereals prevail in the diet, and the preference is given to whole grains and meals.

Components of the Mediterranean diet and their effects on the human health

Today, researchers are sure that the effect of the MD on the cardiovascular system and the risk of its diseases is similar to the powerful effect of modern pharmaceuticals, such as aspirin, statins and fibrates (a group of agents for the prevention and treatment of atherosclerosis), some antihypertensives.

Proteins in the MD

Proteins have mainly plastic functions and promote new cell and tissue growth; various proteins also act as hormones, protective antibodies that perform immune (protective) functions in the body, as regulators of a wide variety of biochemical processes (ferments, or enzymes), etc.

Animal and plant proteins are commonly distinguished. Animal proteins are considered to have more nutritional properties - they contain all necessary amino acids, including the essential ones, in the optimal ratio. Plant proteins can hardly meet the body’s needs for amino acids, and a larger intake is required to meet these needs. In addition, they are less absorbed by the body.

The main source of animal protein in the MD is fish and seafood as the most common and available in the region in comparison with meat, which, however, is also not excluded and should be preferred as low-fat varieties of meat and poultry. In addition, the source of high-value protein is dairy represented in the MD mainly by cheese, but in Turkey, Greece, the Balkans and in some other regions, dairy products such as yogurt are widely used. Eggs also contain high-value protein, as well as saturated fats, which will be discussed below.

Plant proteins are widely represented in the MD, because it focuses on plant foods. The main supplier of vegetable protein is legumes (primarily beans), as well as nuts and seeds. Among plant proteins, a protein of cereal crops - gluten - is distinguished. This protein is given special focus, as it plays a significant role in the development of a serious disease of the GI tract - celiac disease (gluten-sensitive enteropathy). Some people (1 in 3000) have a genetic predisposition to gluten intolerance, as a result, their intestinal mucosa is destroyed and nutrients are poorly absorbed almost since birth. However, in recent years, gluten was blamed not just for this pathology. There are numerous data on the possible effects of gluten on a variety of neuropsychic disorders. A certain beneficial effect of the diet excluding gluten has been shown on a number of pathological neuropsychiatric processes: schizophrenia, anxiety, confusion and inhibition of consciousness, autism, etc. The main cereals containing gluten are wheat, rye, oats, barley. Gluten-free options of the MD are hitting big now, they exclude the effect of this component on the human body, but possess all the healthy properties of this diet.

Fats in the MD

In our mind, the word “fats” is strongly linked with such concepts as “obesity”, “being overweight”, etc. But fats are by no means superfluous, this is an absolutely indispensable dietary component. First of all, fats have an energy function, usually providing the body with essential calories. 1 gram of fats contains twice as more calories as 1 gram of proteins or carbohydrates.

Fats are molecules, the bulk of which consists of the so-called fatty acids. The structure of these acids defines the properties of certain fats, so people distinguish between saturated and unsaturated fatty acids.

The source of saturated fats in the MD are products of animal origin, primarily, meat, milk, fermented dairy and eggs. This category of fats provides the most energy and, without proper physical activity, tends to be deposited in adipose tissue as reserves for a “rainy day”. That is why their moderate intake is advised. Classical versions of the MD include little saturated fat, its share in the energy value of the diet is just 9%, while unsaturated fat accounts for 24%, proteins - 15%, all the rest is ensured by carbohydrates (about one half).

Unsaturated fatty acids are a kind of “youth elixir of the 21st century”. It seems that they were studied in so many academic works as no other chemical compound throughout the history of science was honored. The most essential for the human health are the so-called omega-3 and omega-6 polyunsaturated fatty acids (PUFAs). Omega-3-PUFAs are represented in the MD as fish and partially seafood, and omega-6-PUFAs are contained in seeds, nuts and, mostly, olive oil. It is proved that PUFAs normalize the blood lipid spectrum, that is, the balance of high-density lipoproteins (HDL), low (LDL) and very low density (VLDL). It is their percentage in the blood, as it is believed today, that defines the risk of atherosclerosis and, as a consequence, IHD and cerebrovascular disturbances.

Carbohydrates in the MD

Carbohydrates are the basis of any normal, balanced diet. No wonder they are placed in the bottom of the diet pyramid - at its base. Primarily, carbohydrates supply energy for the body. The nutrition science defines two types of food carbohydrates - simple and complex. Simple carbohydrates are all sugars consisting of one or two molecules. These include commonly known glucose, fructose, sucrose, galactose and many others. They are also called “fast” carbohydrates, which reflects their physiological ability to be quickly absorbed in the intestines, quickly saturate blood causing almost an instant rise in blood sugar levels and an equally rapid surge in the insulin level, whose main role is to ensure access of this sugar to all body cells without exclusion. Normally, after a short time (half an hour or one hour), this sugar from the blood, thanks to insulin, gets into the nervous system (which boosts brain performance for a short time), liver (where further transformations of sugars occur, including, into fats), muscles (where excess glucose is stored in the form of glycogen - a complex carbohydrate similar to starch). Insulin deficiency and insulin resistance cause a prolonged delay of sugars in the blood and cell starvation, i.e., diabetes.

Complex carbohydrates consist of numerous glucose molecules linked together into ramified huge molecular structures. For their digestion, special gut enzymes are required, and the process of splitting these large molecules and the absorption of the cleaved fragments (glucose molecules) into the blood takes place slowly and gradually, which ensures a constant (not abrupt) level of glucose in the blood. In this case, glucose has time to be disposed of by tissues, and not be stored as glycogen or fats (unless in certain circumstances, for example, previous active exercise, depleted reserves).