The Mediterranean Diet is a widely recognized healthy eating pattern that mimics the traditional food consumption habits of people living in countries bordering the Mediterranean Sea. This pattern is characterized by a high intake of whole foods like vegetables, fruits, whole grains, and legumes, with olive oil serving as the primary source of fat. It is distinguished by its low consumption of red meat and sweets, favoring fish and poultry in moderation. The modern formalized diet is the result of decades of observation and scientific investigation that sought to identify the reasons behind the unique longevity observed in certain populations. This article explores the historical origins and scientific identification of this dietary model.
The Regional Foundation
The dietary pattern that would eventually be formalized as the Mediterranean Diet was not originally a prescribed health regimen but a simple cultural tradition shaped by geography and economy. In the mid-20th century, particularly in regions like Crete, Greece, and southern Italy, populations relied heavily on locally sourced and seasonal foods. Their consumption patterns were built around what the land could sustain, leading to a diet naturally rich in plant-based ingredients.
Daily meals frequently centered on bread, cereals, tubers, and large quantities of fresh vegetables and fruits. Olive oil, a staple crop of the region, was used as the main cooking and dressing fat, providing a source of monounsaturated fatty acids. Meat, especially red meat, was consumed sparingly, often reserved for special occasions, with fish and seafood being more common protein sources along the coastlines.
Ancel Keys and the Seven Countries Study
The scientific identification of this regional tradition as a health model is largely attributed to the American physiologist Ancel Keys and his wife, chemist Margaret Keys. Ancel Keys first observed a noticeable disparity in cardiovascular health between Americans and populations in countries like Italy and Greece during his travels in the 1950s. He noted that despite high fat intake in some Mediterranean regions, the rates of coronary heart disease (CHD) appeared significantly lower than in the United States and Northern Europe.
This observation led to the ambitious epidemiological research project known as the Seven Countries Study, which launched in the late 1950s and early 1960s. The study enrolled 16 cohorts of middle-aged men from seven different countries, including the United States, Finland, the Netherlands, Italy, Greece, Yugoslavia, and Japan. Its goal was to examine the relationship between diet, lifestyle, and the incidence of CHD. The research scientifically confirmed Keys’ hypothesis, linking the traditional eating patterns of the Greek and Italian cohorts to lower rates of heart disease and mortality.
The scientific analysis demonstrated that the low incidence of CHD in these Mediterranean populations correlated with a low intake of saturated fatty acids. The findings showed that the plant-focused diet, characterized by olive oil, vegetables, and low amounts of meat and dairy, offered a protective effect. Keys’ work provided the rigorous scientific evidence that elevated the traditional regional diet to a scientifically recognized pattern for promoting cardiovascular health.
Standardizing the Diet Model
The transition from a scientific finding to a public health tool occurred decades after Keys’ initial research, requiring the collaboration of health organizations and academic institutions. In 1993, the dietary pattern was formally standardized and presented to the public through the creation of the Mediterranean Diet Pyramid. This project was a joint effort between the non-profit Oldways Preservation Trust, the Harvard School of Public Health, and the World Health Organization (WHO).
The team, which included experts like Dr. Walter Willett, created the pyramid to graphically represent the recommended food groups and consumption frequency. The Mediterranean Diet Pyramid placed an emphasis on daily consumption of whole grains, fruits, vegetables, and olive oil at its base. It also included weekly recommendations for fish and poultry, while placing red meat and sweets at the very top for infrequent consumption. This pyramid model translated the complex scientific findings of the Seven Countries Study into an accessible, actionable guide for consumers worldwide.