Ancel Keys and the Seven Countries Study
The story of the Mediterranean diet's modern-day recognition begins with Ancel Keys, a University of Minnesota physiologist. Keys became interested in the link between diet and cardiovascular disease after observing that heart disease rates in countries recovering from post-WWII famine dropped significantly, only to rise again as prosperity returned. This observation, combined with the high incidence of heart attacks among affluent American men, led him to hypothesize a connection between fat-heavy diets and heart health.
Keys' interest peaked during a sabbatical in Oxford in 1951, where he learned about the low heart disease rates in Southern Italy. He established a portable laboratory in Naples and began to collect data, confirming lower serum cholesterol levels and lower rates of coronary disease compared to American populations. These early findings motivated him to launch a more comprehensive, cross-cultural study.
The Birth of the Seven Countries Study
In 1958, Keys initiated the Seven Countries Study (SCS), the first multinational epidemiological study of its kind. The study enrolled 12,763 middle-aged men from 16 cohorts across seven countries: the United States, Finland, the Netherlands, Italy, Greece, former Yugoslavia, and Japan. He deliberately chose these populations for their contrasting dietary habits. Over decades, Keys and his team monitored these men, collecting data on their diet, lifestyle, and health outcomes.
The SCS provided compelling evidence that low consumption of saturated fats, characteristic of the Mediterranean cohorts in Italy and Greece, correlated with lower rates of coronary heart disease. In contrast, cohorts with higher saturated fat intake, such as those in Finland and the United States, experienced higher rates of heart disease.
Keys' Contribution Beyond Research
Ancel Keys and his wife, Margaret, were not just researchers; they were also communicators. They wrote two bestselling books, Eat Well and Stay Well and How to Eat Well and Stay Well the Mediterranean Way. Published in 1959 and 1975, respectively, these books translated complex scientific findings into practical, accessible advice for the general public, effectively popularizing the Mediterranean diet concept worldwide. The Keys also embodied the lifestyle themselves, living in the village of Pioppi, Italy, for many years, a region known for its high number of centenarians.
The True Origins of Mediterranean Eating Patterns
While Ancel Keys is the founder of the modern concept of the Mediterranean diet, the eating patterns themselves have deep historical roots, evolving over thousands of years.
Ancient Influences on Mediterranean Diet
The diet observed by Keys was a product of a rich history influenced by ancient civilizations, agriculture, and trade:
- Ancient Greeks and Romans: Emphasized the consumption of wheat, olives, and grapes, which formed the cornerstone of the traditional dietary pattern.
- Geography and Climate: The temperate climate and rocky soil favored the cultivation of plant-based foods, olives, and grapes over animal husbandry.
- Trade Routes: Later influences came from the Islamic Golden Age, which introduced new ingredients like rice and citrus fruits, further enriching the regional cuisines.
- Cultural Practices: The traditional diets were shaped by available local foods, economic conditions, and religious practices.
Traditional vs. Modern Dietary Interpretations
Ancel Keys defined a general pattern, but the specific food choices vary significantly across the 22 countries bordering the Mediterranean Sea. The modern diet often promoted globally is an amalgamation of these different regional traditions, adapted for contemporary health guidelines and food availability. The table below compares the core principles of the traditional diet observed by Keys versus a typical Western dietary pattern.
| Dietary Aspect | Traditional Mediterranean Diet | Typical Western Diet |
|---|---|---|
| Primary Fat Source | Extra virgin olive oil | Saturated and trans fats from butter, processed foods |
| Main Carbohydrates | Whole grains, legumes, vegetables | Refined grains, sugars |
| Protein Sources | Fish, poultry, legumes (moderate); very low red meat | High consumption of red meat, processed meats |
| Dairy Consumption | Moderate amounts, mainly as cheese or yogurt | Higher intake of milk, cheese, and high-fat dairy |
| Fruit & Vegetables | Abundant daily intake | Lower overall consumption; often limited variety |
The Enduring Legacy
Ancel Keys' work was foundational in shifting the scientific and public conversation around diet and chronic disease. While his initial studies had some limitations, subsequent research has repeatedly confirmed the health benefits of the Mediterranean eating pattern. The PREDIMED study, for example, showed a significant reduction in cardiovascular risk among participants following the diet supplemented with extra-virgin olive oil or nuts.
The Mediterranean diet's rise to prominence serves as a powerful testament to the value of epidemiological research in public health. It highlights that the most effective dietary advice is often rooted not in fads, but in the long-established and time-tested eating habits of healthy populations. By shining a scientific light on traditional diets, Ancel Keys provided the world with a valuable, evidence-based roadmap for better health. For more detailed information on the Seven Countries Study, its methodology, and findings, visit the Seven Countries Study website.
Conclusion
While the food traditions of the Mediterranean basin developed over millennia, American physiologist Ancel Keys is rightly credited as the founder of the Mediterranean diet concept in its modern, scientifically validated form. His landmark Seven Countries Study provided the first robust epidemiological evidence linking the plant-based, olive oil-rich diet of Southern European populations to lower rates of heart disease. By translating his scientific observations into popular books with his wife, Margaret, Keys successfully introduced the world to this enduring and healthful eating pattern, forever changing the field of nutrition science. The diet's legacy continues today, supported by decades of scientific research and recognized globally as a model for healthy living.
