The Mediterranean Diet: From Ancel Keys to the Present, Part II

The beginning of the Mediterranean Diet’s “discovery” can be traced to Ancel Keys’ 1951 arrival in Rome, Italy. He had been sent by the FAO (the UN Food and Agriculture Organization), which had organized a convention to address nutrition in Europe after the end of WWII. Keys was at the time quite well known as a nutritionist and physiologist because he had invented the K ration, a US military food ration conveniently providing a few days of nourishment that was initially given to paratroopers but then expanded to all soldiers. Ancel Keys was well respected not only for this, but also for “The Biology of Human Starvation”, a work to this day still unsurpassed as the most important study on the effects of starvation on the human body.

For these reasons Keys was invited to preside over the inaugural sessions of the nutrition conference. After listening to his colleagues talk unanimously about deficiencies; vitamin deficiencies, protein deficiencies, he shared a thought, “perhaps we in the United States have the reverse problem; perhaps we have an excess of certain dietary elements”, referring certainly to the fact that in 1951, fifty per cent of adult American male deaths were caused by a heart attack, the causes of which were still unknown.

Yet his colleagues, scientists from around the world, did not take interest in this concern and did not see this phenomenon as a serious epidemic. Only one person, the Neapolitan doctor Gino Bergami was intrigued by Keys’ statement, noting that in Naples there were no incidents of cardiovascular disease or heart attacks.

Keys later sent a telegram to the Neapolitan professor while at Oxford for his year of sabbatical, asking him whether his statement was indeed true about the lack of cardiovascular problems in Naples. Bergami invited Keys to come and see for himself, which he soon did in the company of his wife Margaret Haney, then a biologist at the Mayo Foundation.

The couple began their initial studies in 1951-1952 by screening adult Neapolitan males between 39 and 59, just as they had done with an American group. Both studies consisted mostly of lower-middle class workers, and in the Neapolitan study included many workers from ‘Italsider’, a large industrial enterprise.

When the Keys analyzed the blood samples, an obvious difference between the two groups of specimens was revealed: the American blood had high levels of cholesterol while the samples from Naples did not.
In this way, the Keys were the first to investigate the effects of cholesterol. The issue had just begun gaining some attention however, and they were no longer the only ones interested.

The study posed many interesting questions. Salaries in the United States were high and yet people were not healthy. The population in Naples had generally lower wages, less sanitary working environments, and yet had higher life expectancy than their American counterparts.

In the years just after WWII, not many were keen to believe that the Mediterranean Diet found in Naples was a champion of health and longevity, but that is exactly what the Keys proposed. In 1957 they began the largest epidemiological study in history, known as the ‘Seven County Study’. The impressive study followed 12 thousand people over a period of 35 years and involved comparing the lifestyles and diets of the following countries: Italy, the United States of America, Finland, Yugoslavia, Japan, the Netherlands and Greece. Today this study is recognized as being invaluable for having discovered the beneficial qualities of the Mediterranean Diet.

The Keys’ initial hypothesis proved correct: diet and lifestyle have a direct effect on our health, including cardiovascular health, and that the Mediterranean Diet is particularly useful in prolonging life.