In the 1960s, researchers noted that people in southern Europe, particularly on the Greek island of Crete, had low rates of heart disease, which they attributed to the traditional diet. Numerous population studies since then have linked this and similar diets of countries around the Mediterranean Sea to a lower risk of cardiovascular disease, diabetes, cancer and Alzheimer’s and Parkinson’s disease, as well as longer life.
No one knows for sure what makes the diet healthful. It is high in healthful unsaturated fats from olive oil and fish and relatively low in saturated fat (and no trans fat from processed foods). Because it's based on plant foods, the diet is also high in fiber and other potentially protective compounds. And wine has cardioprotective effects from its alcohol and polyphenols. These and other dietary factors may act together to have anti-inflammatory and other beneficial effects in the body.
Of course, the cuisines of Spain, Greece, Italy, Morocco and other Mediterranean countries vary, even within the same country. The traditional way of life in this region, which includes a lot of physical activity, may also contribute to overall good health.
But keep in mind that while the Mediterranean diet has gotten great press, it’s hardly the only healthful world cuisine. Consider the Japanese, who consume little olive oil or red wine yet have the longest life expectancy in the world. What healthy diets around the planet have in common—and what we have long recommended—is a heavy emphasis on plant foods.