Mediterranean diet can 'boost levels of good cholesterol'

Up to four tablespoons added to the traditional diet enhances the cardioprotective benefits of "good" high-density lipoproteins - HDL - compared to other diets. Over a year those

on an olive oil rich Mediterranean diet got the most health benefits from good cholesterol compared to those who had a similar diet with a daily extra fistful of nuts. This included removing

bad cholesterol from artery plaques and expelling it from the body, stopping bad cholesterol forming plaques and keeping blood vessels open and flowing. High levels of "bad"

cholesterol and a type of blood fat triglyceride are associated with an increased risk of heart and blood vessel diseases. Good cholesterol was associated with a lower risk because these

lipoproteins help eliminate the excess cholesterol from the bloodstream. Senior author Dr Montserrat at the Hospital del Mar Medical Research Institute in Barcelona said: "However,

studies have shown that HDL doesn't work as well in people at high risk for heart attacks, strokes and other cardiovascular diseases, and that the functional ability of HDL matters as

much as its quantity. "At the same time, small-scale trials have shown that consuming antioxidant-rich foods like virgin olive oil, tomatoes and berries improved HDL function in humans.

"We wanted to test those findings in a larger, controlled study." The study involved 296 people with an average age of 66 at high risk of cardiovascular disease participating in

the PREDIMED study. They were randomly assigned to either a traditional Mediterranean diet enriched with virgin olive oil of about four tablespoons each day, a traditional Mediterranean diet

enriched with a fistful of extra nuts or a healthy "control" diet that reduced consumption of red meat, processed food, high-fat dairy products and sweets. In addition to

emphasising fruit, vegetables, legumes, such as beans, chickpeas and lentils, and whole grains, both Mediterranean diets included moderate amounts of fish and poultry. Blood samples was

taken at the start and a year later. It found only the control diet reduced total and LDL cholesterol levels. None of the diets increased HDL levels significantly, but the Mediterranean

diets did improve HDL function. But the improvement in HDL function was much larger among those consuming an extra quantity of virgin olive oil. This included boosting its ability to remove

cholesterol from plaque in the arteries and transport it to the liver where it is used to produce hormonal compounds or eliminated from the body, a process known as reverse cholesterol

transport. MEDITERRANEAN DIET: DR CHRIS REVEALS NEW FINDINGS It also increased antioxidant protection, the ability of HDL to counteract the oxidation of "bad "cholesterol -

low-density lipoproteins LDL - which has been found to trigger the development of plaque in the arteries. It also improved its vasodilator capacity, which relaxes blood vessels, keeping them

open and blood flowing. But Dr Montserrat said: "We were surprised to find that the control diet, which like the Mediterranean diets was rich in fruits and vegetables, had a negative

impact on HDL's anti-inflammatory properties. "A decrease in HDL's anti-inflammatory capability was associated with cardiovascular disease. GETTY Tomatoes are also rich in

antioxidants "Participants on the Mediterranean diets did not experience a decline in this important HDL function. "But the differences in results between the diets were relatively

small because the modifications of the Mediterranean diets were modest and the control diet was a healthy one. " Dr Montserrat added: "Study results are mainly focused on a high

cardiovascular risk population that includes people who can obtain the most benefits from this diet intervention. "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." The study was published in the journal Circulation.