The study was one of the largest of its kind and involved about 7,500 people in Spain. Participants who ate a Mediterranean-style diet with lots of olive oil or nuts had a 30 percent lower risk of major cardiovascular problems compared to those who were told to follow a low-fat diet but who in reality, didn’t cut fat very much.
The Mediterranean lifestyle consists of lots of fruit, fish, chicken, beans, tomato sauce, salads, and wine and little baked goods and pastries. The results were published by the New England Journal of Medicine and were discussed at a nutrition conference in Loma Linda, Calif.
The study examined people in the 55 to 80 year age range and did not require people to follow rigid menus or meet calorie goals as weight loss was not the aim, and only 7% of study participants dropped out within 2 years.
Researchers also provided the nuts and olive oil, so it didn’t cost participants anything to use these relatively pricey ingredients. The type of oil may have mattered – they used extra-virgin olive oil, which is minimally processed and richer than regular or light olive oil in the chemicals and nutrients that earlier studies have suggested are beneficial.
Doctors tracked a composite of heart attacks, strokes or heart-related deaths. There were 96 of these in the Mediterranean-olive oil group, 83 in the Mediterranean-nut group and 109 in the low-fat group and found that the risk of heart disease was conclusively lowered.