In 1945, a nutritionist named Ancel Keys, who was in Pioppi, Italy, with the victorious Allied army, noticed something curious. Italians were less prone to obesity and cardiovascular disease than Americans, despite diets with similarly high levels of fats and carbohydrates. Although this discovery was little-noticed at the time, it would come to spark a re-evaluation of the relationship between how people eat and their health. By the 1990s, the insights of Keys and those who followed in his footsteps had coalesced into the "Mediterranean diet."
What scientists had learned is that while the amount of fat a person consumes is important, the type of fat also matters. Mediterranean cuisine involves olive oil and other sources of monounsaturated fats, unrefined grains, lots of fruits and vegetables, a variety of seafood and poultry at moderate levels, and low to moderate amounts of dairy products and red meat. In addition, there are a lot of vineyards in the area, meaning wine is a common element of meals in the area, though there is no clear consensus on the health benefits wine may offer.
The result of this diet is noteworthy. In one study, people following the Mediterranean diet showed a decrease in cholesterol ratio—a measure of the amount of harmful LDL cholesterol—of 16 percent. Research has also shown that children who successfully kept up with the Mediterranean diet were 15 percent less likely to be obese or overweight and almost as much less likely to have significant excessive weight gain. This pattern held regardless of whether the children actually lived in the Mediterranean region. Though the stereotype is that children simply don’t eat foods that are good for them, they will if they get acclimated at a young age.
Another study has found an additional benefit: the Mediterranean diet helps protect the brain. People on the Mediterranean diet may be less likely to develop dementia and other forms of age-related cognitive decline. In fact, a review of studies seemed to indicate that eating in this way may actually enhance cognitive functioning, improving memory, attentiveness, use of language, and other things people do with their brains.