By Laura Sesana, @lasesana
WASHINGTON, January 17, 2014–The possible health benefits of the Mediterranean diet continue to garner attention with a study published earlier this month concluding eating like the Greeks, Spanish and Italians may reduce the risk of type 2 diabetes.
Published in the Annals of Internal Medicine on January 7, the study followed 3541 men and women between the ages of 55 to 80 for four years. Participants were assigned to one of three groups. Two groups followed a Mediterranean diet plus either 50 mL of olive oil daily or 30g of mixed nuts daily. The remaining control group was assigned a low-fat diet.
After four years, the study showed that while there was no difference in changes in body weight, physical activity or waist circumference between the three groups, 101 participants in the control group developed diabetes, compared with 80 in the olive oil group and 92 in the mixed nuts group.
Another study released in 2013 in the New England Journal of Medicine concluded that a similar Mediterranean diet supplemented with olive oil and nuts reduced cardiovascular risk when compared to a conventional low fat diet.
The study took place in Spain and followed over 7,400 subjects between the ages of 55 and 80 for approximately five years. None of the subjects presented cardiovascular disease at the beginning of the study, but were at high risk for cardiovascular disease. Risk factors included diabetes, smoking, obesity, family history of cardiovascular disease, and hypertension.
Subjects were randomly assigned to either a Mediterranean diet supplemented with olive oil, a Mediterranean diet supplemented with nuts, or a low-fat control diet. After five years, the 2013 study found that both Mediterranean diet groups saw close to a 30% reduction in cardiovascular events like strokes and heart attacks when compared to the individuals in the low-fat control group.
The components of the Mediterranean diet
One source defines a traditional Mediterranean diet as one characterized by high components of olive oil, fruit, nuts, vegetables, and cereals; a moderate component of fish and poultry; and small component of dairy products, red meat, processed meats, and sweets. The Mediterranean diet also includes drinking wine with meals in moderation.
With nearly 40% of calories from fat, the Mediterranean diet t is nevertheless very low in saturated fats due to the olive oil and nut components.
In the 2013 study, participants in the Mediterranean groups were asked to eat between two to three servings of fruit and two to four servings of vegetables per day. They were also asked to consume at least three servings of fish and three servings of legumes per week. Those already accustomed to drinking wine with meals were asked to drink at least seven glasses per week. Mediterranean group participants were also asked to eat white instead of red meats and avoid commercially baked cookies and pastries as well as limit intake of processed meats and dairy products.
The Mediterranean diet group was encouraged to dress, stir-fry, and sauté vegetables in olive oil rather than steaming or using low-fat or fat-free spreads or dressings. Both Mediterranean groups were also counseled to substitute fat-free or low-fat processed snacks with a handful of nuts.
An interesting conclusion that can be drawn from the studies is that a low-fat diet may have little effect on reducing the risk of cardiovascular disease and may not be as effective as the Mediterranean diet in reducing the risk of diabetes. Even though the participants in the Mediterranean groups did not lose weight in either study, they did significantly reduce their risk for heart disease and diabetes.
Researchers caution, however, that theses studies have limitations. The diabetes study, for example, points out that its participants were all older and white, making it unclear whether their findings apply to other age groups or ethnicities. The researchers of the heart disease study also highlight that participants were already at high risk for cardiovascular disease and already lived in a Mediterranean country, where it was easy to follow a Mediterranean diet.
Both studies stress the need for further research to determine how results will apply to other age groups and ethnicities; people with medium to low risk of heart disease and diabetes; and those who live in other parts of the world.