The Mediterranean diet has been touted as one of the healthiest in the world. But why is this exactly?

Scientists believe it is largely due to its incorporation of olive oil. A study recently published in Circulation has found that olive oil may have the potential to lower the risk of heart disease, as it helps maintain healthy blood flow and clear debris from arteries.

"A Mediterranean diet rich in virgin olive oil improves the function of high-density lipoproteins, HDL, popularly known as 'good' cholesterol," said lead study author Dr. Alvaro Hernáez of the Hospital del Mar Medical Research Institute in Barcelona.

This study examined data from 296 older adults (with an average age of 66 years) who were at risk of cardiovascular disease, and randomly assigned them to one of three diets: a Mediterranean diet including one litre per week (approximately four tablespoons daily) of extra virgin olive oil; a Mediterranean diet supplemented with 30 grams of nuts per day; or a low-fat diet. These diets were follow by the participants for one year.

The Results

Blood tests and lab work showed that the group who followed the Mediterranean diet with extra virgin olive oil had better HDL readings.

So, how exactly does the olive oil help? "Our hypothesis is that these dietary antioxidants may bind to HDL particles and protect them against different kinds of attacks," Hernáez said. "As HDLs are more protected, they can perform their biological functions more efficiently and, therefore, they are able to remove cholesterol from arteries or contribute to the relaxation of blood vessels for longer."