The Health Benefits Of Extra Virgin Olive Oil : A Further Study
Montserrat Fitó, Ph.D., is the senior author of research by the Cardiovascular Risk and Nutrition Research Group at the Hospital del Mar Medical Research Institute in Barcelona, Spain. Fitó and team’s findings were published in the American Heart Association’s journal Circulation.
There are two types of molecules called lipoproteins that carry cholesterol in the blood: low-density lipoprotein (LDL) and high-density lipoprotein (HDL).
LDL is known as “bad” cholesterol, since having high levels of LDL can bring about plaque build-up in the arteries, which can result in heart disease and stroke. HDL is known as “good” cholesterol; HDL (good) absorbs cholesterol and carries it to the liver where it is flushed from the body. Having high levels of HDL (good) reduces heart disease and stroke.
The research team aimed to determine whether eating a Mediterranean diet enriched with extra virgin olive oil or nuts over a long period of time would improve the beneficial properties of HDL (good) cholesterol in humans.
Fitó and collaborators randomly selected a total of 296 individuals who had a high risk of heart disease and were participating in the Prevención con Dieta Mediterránea study. The participants had an average age of 66 and were assigned to one of three diets for a year.
The first diet was a traditional Mediterranean diet enriched with around 4 tablespoons of extra virgin olive oil per day. The second, a traditional Mediterranean diet supplemented with a fistful of nuts each day. The third diet was a healthful “control” diet that contained a reduced amount of red meat, high-fat dairy products, processed foods, and sweets.
Both Mediterranean diets emphasized the inclusion of fruit, vegetables, legumes (such as beans, chickpeas, lentils, and whole grains), and moderate amounts of fish and poultry.
Blood tests were conducted at the start and end of the study to measure LDL (bad) and HDL (good) levels.
Extra Virgin olive oil-enriched Mediterranean diet enhanced HDL function
The researchers found that total and LDL (bad) cholesterol levels were only reduced in the healthful control diet. While none of the three diets significantly increased HDL (good) levels, the two Mediterranean diets improved HDL (good) function, and the improvement was more pronounced in the group enriched with extra virgin olive oil.
The Mediterranean diet enriched with extra virgin olive oil improved HDL (good) functions, such as reversing cholesterol transport, providing antioxidant protection, and enabling vasodilation.
Reverse cholesterol transport is the process in which HDL (good) removes cholesterol from plaque in the arteries and takes it to the liver. Antioxidant protection is the ability of HDL (good) to counteract the oxidation of LDL (bad). Oxidation of LDL (bad) triggers the development of plaque in the arteries.
Lastly, vasodilator capacity, which relaxes the blood vessels, keeps them open, and keeps the blood flowing, is improved by the Mediterranean diet with extra virgin olive oil.
Although the control diet was rich in fruits and vegetables like the two Mediterranean diets, the diet was shown to have an adverse impact on HDL’s (good) anti-inflammatory properties. This negative impact was not observed in the Mediterranean diets. A reduction in HDL’s (good) anti-inflammatory capacity is linked with a greater risk of heart disease.
“Following a Mediterranean diet rich in virgin olive oil could protect our cardiovascular health in several ways, including making our ‘good cholesterol’ work in a more complete way.”