Greek Lessons

The Mediterranean diet was made popular in the U.S. about 15 years ago by Oldways, a nonprofit but industry-supported "think tank," with scientific evidence from Harvard researchers to back it. It includes lots of fresh fruits, vegetables, beans, and grains, moderate amounts of fish, some dairy (mostly yogurt and cheese), and little red meat or sweets. Olive oil, as the main source of fat, and wine, especially red wine, are also key features.

How many people in the Mediterranean area ever ate such an exemplary diet (most don’t today) is debatable. But what’s in-creasingly clear is that a plant-based diet, whether called the Mediterranean diet or something else, is a healthy way to eat.

How solid is the evidence for the Mediterranean diet?

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 local diet. Numerous population studies since then have linked the Mediterranean diet to a lower risk of cardiovascular disease, diabetes, cancer, and Alz-heimer’s and Parkinson’s disease, as well as longer life. And several large clinical trials back up the observations. According to the Harvard researcher Dr. Walter Willett, “Our analyses suggest that healthy food choices that are consistent with the traditional Mediterranean diet, combined with regular physical activity and not smoking, can reduce the rate of heart disease by over 80%, stroke by 70%, and type 2 diabetes by 90%.”

What makes the diet healthful? Is it a particular food?

No one knows for sure, but several features stand out. The diet is high in healthful unsaturated fats from olive oil and fish and low in saturated fats. In particular, olive oil is rich in oleic acid, a mono-unsaturated fat associated with improvements in blood cholesterol and insulin sensitivity, and it contains polyphenols that have antioxidant effects. Because it’s based on plant foods, the diet is also high in fiber and other potentially beneficial phytochemicals. And wine, particularly red wine, has cardio-protective 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. That is, the benefits may come from the diet as a whole, rather than the individual components.

Cuisines around the Mediterranean differ, so couldn’t it be something else that makes these people healthier?

The traditional cuisines of Greece, Italy, Spain, Morocco, and other Mediterranean countries vary, even within the same country. Some people eat more meat, for example. But all cuisines incorporate the same basics, notably lots of produce, grains, and healthful oils. The traditional way of life in this region, which includes lots of physical activity, may also contribute to overall good health. Genes may be involved, too. But even within the Mediterranean area, all else being equal, research shows that people who adhere more closely to the traditional diet reap greater health rewards. Moreover, studies of people eating a Mediterranean-style diet in the U.S. and elsewhere have shown reduced risk of certain chronic diseases, which means that you can benefit wherever you live.

Can the Mediterranean diet help you lose weight?

Despite being high in olive oil, the diet has been linked in several studies to lower body weight or better weight control. In general, plant-based diets are lower in calories than meat-based diets, plus the fiber from plant foods helps fill you up, so you may eat less overall. Keep in mind that the traditional Mediterranean diet also has modest portion sizes and is accompanied by regular physical activity—two key ingredients of weight management.