The Mediterranean way of eating is ancient. But the world’s awareness of it as a scientifically validated path to health and longevity is surprisingly recent – and it owes much of its origins to one quietly persistent American scientist and an unexpected discovery on a Greek island.

A Surprising Finding on Crete

In 1948, American social scientist Leland Allbaugh traveled to Crete on behalf of the Rockefeller Foundation to study what was then considered one of Greece’s most underdeveloped regions. What he found confounded expectations. Despite widespread poverty and some of the lowest incomes in the country, the men of Crete were remarkably healthy. They suffered only a third as many heart disease-related deaths as Americans. Cancer was rare. Their nutrition – built around olive oil, whole grains, vegetables, fruit, and fish – was, paradoxically, among the most protective in the world. Allbaugh published his findings in 1953. They would quietly set the stage for something much larger.

Ancel Keys and the Question That Changed Everything

Around the same time, a professor of physiology named Ancel Keys was trying to understand why middle-aged American men were dying suddenly of heart attacks at alarming rates. The question seemed straightforward. The answer, it turned out, would take decades to unravel.

In 1951, a colleague mentioned in passing that workers in Naples rarely suffered heart attacks. Keys was intrigued enough to take an academic sabbatical in Italy, where he and his wife Margaret – a biochemist and essential intellectual partner in his work – began studying blood pressure, cholesterol, and nutrition among the local population. What they found was striking enough to launch one of the most ambitious nutritional studies in scientific history.

The Seven Countries Study

Keys assembled researchers from around the world to conduct a systematic comparison of diet, lifestyle, and heart disease risk across seven nations with dramatically different eating habits: Japan, Finland, Greece, Italy, the former Yugoslavia, the Netherlands, and the United States. Nearly 13,000 healthy men between the ages of 40 and 59 were enrolled and monitored for 25 years – with diet and lifestyle documented at five-year intervals. As participants aged into their 80s and 90s, cognitive decline was added to the list of measures being tracked.

The results, published in 1980, were unambiguous. Lifestyle and diet were directly and powerfully linked to the risk of coronary artery disease. And the populations living in regions where olive trees grow naturally – following a diet centered on plants, olive oil, fish, and whole grains – showed some of the highest longevity rates in the world, alongside the lowest incidence of heart disease, cancer, and other chronic conditions.

The numbers told the story with startling clarity. Deaths from heart disease per thousand: Finland, 171. The United States, 92. Crete – just 3.

The so-called “poor man’s diet” of Crete – simple dishes built around fresh vegetables, olive oil, seasonal fruit, and very modest amounts of meat or fish – turned out to be the most protective dietary pattern ever documented.

Notably, while the Japanese diet was very low in fat and the Mediterranean diet relatively high in it, the critical difference lay in the type of fat: 35 percent of Mediterranean calories came from unsaturated fats, primarily olive oil. Finland and the United States, by contrast, were heavy in saturated animal fat – and their heart disease rates reflected it.

A Legacy That Keeps Growing

The Seven Countries Study opened a door that has never closed. Since its publication, more than 6,500 scientific studies have examined the health effects of Mediterranean dietary patterns across different populations and conditions – from cardiovascular and metabolic disease to neurodegeneration, cancer, depression, respiratory illness, and bone health. The evidence has only grown stronger with time.

In November 2010, the Mediterranean diet received its highest formal recognition when UNESCO added it to the Representative List of the Intangible Cultural Heritage of Humanity, at the request of Spain, Greece, Italy, and Morocco. Croatia, Portugal, and Cyprus joined the inscription in 2013 – an acknowledgment not just of the diet’s health value, but of its cultural depth and irreplaceable role in the identity of the region.

As for Ancel Keys himself – he eventually moved to the Mediterranean permanently, settling in the village of Pioppi on Italy’s Cilento Coast, a region long known for its unusually high concentration of centenarians.

Keys and his wife Margaret didn’t just study the Mediterranean way of life – they lived it. Together they wrote How to Eat Well and Stay Well, The Mediterranean Way, a cookbook that brought their research into home kitchens and reflected a genuine personal conviction that this way of eating was worth adopting for life. They weren’t simply reporting on the Mediterranean; they were practicing it daily.

The results speak for themselves. Ancel Keys died on November 20, 2004, just two months shy of his 101st birthday. Margaret Haney Keys lived until the age of 97, passing away on December 3, 2006. Between them, nearly two centuries of life – lived, by their own design, the Mediterranean way.