A、It involved 13,000 researchers from Asia, Europe and America. B、It was conducted in seven Mid-Eastern countries in the 1950s.

The Mediterranean diet is based upon the eating patterns of traditional cultures in the Mediterranean region.
   Several noted nutritionists and research projects have concluded that this diet is one of the most healthful in the world in terms of preventing such illnesses as heart disease and cancer, and increasing life expectancy.
   The countries that have inspired the Mediterranean diet all surround the Mediterranean Sea. These cultures have eating habits that developed over thousands of years. In Europe, parts of Italy, Greece, Portugal, Spain, and southern France adhere to principles of the Mediterranean diet, as do Morocco and Tunisia in North Africa. Parts of the Balkan region and Turkey follow the diet, as well as Middle Eastern countries like Lebanon and Syria. The Mediterranean region is warm and sunny, and produces large supplies of fresh fruits and vegetables almost year round that people eat many times a day. Wine, bread, olive oil and nuts are other staples of the region, and the Mediterranean Sea has historically yielded abundant quantities of fish.
   International interest in the therapeutic qualities of the Mediterranean diet began back in the late 1950s, when medical researchers started to link the occurrence of heart disease with diet. Dr. Ancel Keys performed an epidemiological analysis of diets around the world. Entitled the Seven Countries Study, it is considered one of the greatest studies of its kind ever performed. In it, Keys gathered data on heart disease and its potential causes from nearly 13,000 men in Greece, Italy, Croatia, Serbia, Japan, Finland, the Netherlands, and the United States. The study was conducted over a period of decades. It concluded that the Mediterranean people in the study enjoyed some significant health advantages. The Mediterranean groups had lower mortality rates in all age brackets and from all causes, particularly from heart disease. The study also showed that the Mediterranean diet is as high or higher in fat than other diets, obtaining up to 40% of all its calories from fat. It has, however, different patterns of fat intake. Mediterranean cooking uses smaller amounts of saturated fat and higher amounts of unsaturated fat, mostly in the form of olive oil. Saturated fats are fats that are found principally in meat and dairy products, although some nuts and vegetable oils also contain them. Saturated fats are used by the body to make cholesterol, and high levels of cholesterol have since been directly related to heart disease.
Questions 23 to 25 are based on the recording you have just heard.
23. What has research concluded about the Mediterranean diet?
24. What do we learn about the Seven Countries Study?
25. What do we learn about the Mediterranean people from the Seven Countries Study?