Many still wonder what the Mediterranean diet actually is
The term “Mediterranean diet” was coined in the 1950s by the American researcher Ancel Keys, the first epidemiologist to recognise the health benefits of this style of eating. It is believed that the traditional Mediterranean diet was consumed in the 1950s and 1960s in Greece and southern Italy. In Greece, this diet was particularly common in the rural areas of the island of Crete. More recently, large migrations to cities and the advent of modern technologies.
The Greek diet
The Greek diet in particular, until the ’60s was made up of olives, whole grains, legumes, vegetables, fruit and herbs. The use of these ingredients plus a limited consumption of yogurt, goat cheese, and fish, together with bread, olives and olive oil constitute the major pillars of this diet.
This type of diet is very rich in fats, which count for approx. 30% of total calories in Spain and 40% of calories in the Greek diet. Saturated fats are consumed in limited amounts, whereas mono-unsaturated fatty acids (mainly from olives and olive oil) are very common. Foods of animal origin (like meat and dairy products) are consumed in limited amounts.
Depending on the proximity of the sea, fish can represent an important food source. Fish contributes to the intake of high-quality proteins and omega-3 fatty acids, useful in the prevention of cardiovascular diseases.
The Mediterranean diet is also a good source of carbohydrates, despite the growing trend of diets low in such nutrients (low-carb diets). The high consumption of fruit, vegetables, and legumes makes this type of nutrition an excellent strategy to consume bioactive compounds (phytosterols, bioactive compounds, etc.). This diet is also high in fibre, vitamins, and minerals, especially the precious folates that reduce cardiovascular risk. Folic acid in particular, unlike folates, is not present in nature, but has often been prescribed in the form of food supplements in order to reduce levels of homocysteine. The latter is a factor that is found in the blood and that seems to be associated with an increased risk of developing cardiovascular diseases. However, taking these drugs has raised some doubts that folic acid taken as medicine may increase the risk of colorectal cancer.
The Mediterranean diet: A UNESCO heritage
Despite the fact that the Mediterranean diet was proclaimed a few years ago a World Heritage Site by UNESCO. Today, this diet is endangered and it is increasingly replaced by western dietary habits. High consumption of animal food products and a reduced (not to say a null) consumption of wholemeal grains, legumes, nuts, fruit, and vegetables are becoming more and more common.
In a study that I carried out on the nutritional data of 15,000 children from eight European countries (participants in the IDEFICS study), I found a very paradoxical result. This was that Swedish children had the highest propensity for a Mediterranean type of diet. On the contrary, the Cypriots had the lowest adherence to a Mediterranean-type diet and many of them ate burgers every day! In these ranking Italian children, sampled in the city of Avellino, were in second place, although with a certain distance from Swedish children.
Differences between different countries
Despite the similarities between the different Mediterranean countries in terms of food, it is now common opinion that there are different Mediterranean-type diets. This is not surprising since the Mediterranean basin is bordered by three different continents: Europe, Asia and Africa, with a total of twenty-one countries that are characterized by very different climates, cultures, traditions and religions.
For example, wine, commonly consumed in southern Europe, is prohibited (like all spirits) in Muslim countries. Alternatively, in France and Italy, eating habits are very different in the north and south. Portugal, on the other hand, although not formally a Mediterranean country, is considered to be “adopted” from the nutritional point of view, due to its habits which are very similar to those of the Mediterranean countries.
Curiously, other countries far from this geographical area, such as California or central Chile, but with climates and products similar to those found in Mediterranean countries (wine and olives for example), have not developed a food tradition comparable to the Mediterranean diet.
Lifestyle and meal times
The traditional Mediterranean diet and its beneficial health effects cannot be fully understood if the cultural context is not also considered. The Mediterranean culture of food includes habits such as fixed meal times, eating as a social activity and, in some countries, the habit of resting after a midday meal (the famous siesta). Other factors such as physical activity, smoking cessation and low stress certainly contribute to a better general state of health. The use of local products, often self-produced (such as the classic garden vegetables), is another important characteristic that determines a higher nutritional quality of the food consumed.
As far as meal times are concerned, lunch is traditionally considered the main meal, although this feature is now increasingly the prerogative of dinner when the family meets again after a day spent at school and work. Even the habit of eating meals at predetermined times, alternating with moments of abstention from food (with the exception of one or two snacks per day), seems to be important for the regulation of satiety and to regulate caloric intake.
The role of physical activity
The high level of physical activity is another factor that may have played a role in determining the health effects of a Mediterranean lifestyle. Finally, exposure to the sun leads to increased production of vitamin D in the body. This vitamin is transformed into a biologically active vitamin under the skin thanks to the effect of ultraviolet rays. Adequate levels of this vitamin contribute to the prevention of cancer, hypertension, and some immunological disorders.