Backed by the strongest scientific evidence, the traditional Mediterranean diet remains the healthiest diet available, with health benefits for a variety of common chronic diseases, including the protection against coronary vascular disease, some forms of cancer, and stroke.
The traditional Mediterranean diet is characterized by a high intake of olive oil, fruit, nuts, various vegetables, and cereals; a moderate intake of fish and poultry; a low intake of dairy products, red meat, processed meats, and sweets; and a moderate amount of red wine consumed with meals. This kind of diet that has evolved over hundreds of years in countries surrounding the Mediterranean Sea is obviously fundamentally different from the modern diets promoted for their often unsupported health benefits today, including the paleo, ketogenic, or grain- and gluten-free diets.
One of the most well-known recent clinical trials in support of the Mediterranean diet was the PREDIMED study, which showed that in subjects with an increased risk of cardiovascular events, the adherence to a Mediterranean diet which was either supplemented with nuts or with extra virgin olive oil provided a significant reduction of cardiovascular events, compared to a control diet (advice to reduce dietary fat). The benefits of both types of Mediterranean diet were so striking that the clinical trial was stopped after a median of 4.5 years.
Even though additional cultural, social and lifestyle factors may be involved, the authors of the study speculated that the lower cardiovascular mortality observed in Mediterranean countries compared to northern European countries or the United States can be explained by adherence to a Mediterranean diet. While it has already been demonstrated in small scientific studies that this diet has positive effects on brain function and even structure, there are now several controlled studies evaluating the beneficial effects of Mediterranean diet in depression, Alzheimer’s disease, and Parkinson’s disease.
A Mediterranean diet is not only good for the heart and the brain, as a recent study on its effect on chronic liver disease demonstrates. The study performed in 1521 patients with Non-Alcoholic Fatty Liver Disease (NALFD) demonstrated that one of the most common liver disorders can effectively be treated simply by adhering to a Mediterranean style, e.g. largely plant based diet.
Amongst the many factors contributing to the undisputable benefits of the Mediterranean style diet are a reduction of unhealthy components of the typical North American diet, which is characterized by high consumption of animal products, refined sugars, processed foods and reduced intake of plant based food (e.g. dietary fiber). It is well known that these factors, in particular the reduction of dietary fiber intake, contribute to a change in the gut’s microbiome. This leads to a low grade activation of the gut’s immune system resulting in increased blood levels of immune system mediators (a condition referred to as metabolic toxemia), affecting every organ in the body, including the heart, the liver and the brain.
There are things to keep in mind when talking about the Mediterranean diet:
The Americanized version of this diet, such as the widely advertised thick layered pizza dough covered with with tons of cheese, large pasta dishes with creamy sauces and lots of red meat, is fattening and most likely no longer provides the benefits reviewed above (even though this has never been tested scientifically).
Traditional diets consumed in countries around the Mediterranean, including but not limited to Spain, Greece and Lebanon, are made up of similar ingredients and presumably have similar health benefits. However, the modern modifications of dietary habits in these countries with increased portion sizes, introduction of high caloric and processed fast foods, increased consumption of animal products, e.g. meat and animal fats, and the modernization of how the consumed plants are grown may have diluted some of the benefits of the traditional forms of the diet.
Mediterranean and Italian diets are not the same. As described in an interesting article by Frank Jacobs, there is a large variety of food and dietary habits based on the different geographic regions of Italy: in Sicily and Sardinia, food is obviously quite different from that in Milan, Bologna or Bolzano in the North. When I discussed this with Marco Cavalieri, producer of organically grown wine and extra virgin olive oil in Fermo, Italy, he told me that generally one can say that the Mediterranean diet is fully adopted in the central and southern Italy, and less so in Northern Italy. But despite the diversity of foods between the different geographic regions, legumes, cereals, vegetables, fruit, fish and extra virgin olive oil make up the basic ingredients.
For example, even in the northern regions, traditional dishes, such as the Milanese risotto, today are made using extra virgin olive oil and accompanied with seasonal vegetables. Marco believes that with its health benefits being widely appreciated, the concept of Mediterranean diet is widespread throughout the Italian cuisine. There is evidence that life expectancy in central-southern Italy, in particular Sardinia (one of the famous Blue Zones) is higher, suggesting that it is the greater adherence to the traditional diet that provides this benefit.
Besides similarities in diet, people in Mediterranean countries share a strong connectedness with the world, including the regions they live in, with family and friends, with history, traditions and religion. As I discussed in The Mind-Gut Connection, this “mind component” of the Mediterranean diet is likely to play an important, yet still underappreciated role in its observed health benefits.