Recent News

Researchers know that the func­tional abil­ity along with the quan­tity of high-den­sity lipopro­teins (HDL) or ​“good” cho­les­terol is needed for pro­mot­ing heart health. A new study finds the Mediter­ranean diet (Med­Diet) increased HDL func­tion, and the improve­ments were larger if the eat­ing plan was aug­mented with an extra amount of vir­gin olive oil.

High lev­els of low-den­sity lipopro­teins (LDL) or ​“bad” cho­les­terol are linked to an increased risk of car­dio­vas­cu­lar dis­ease, while high lev­els of HDL are linked to a decreased risk. LDL pro­motes the buildup of plaque in the arter­ies, but HDL absorbs cho­les­terol and trans­ports it to the liver, where it is removed from the body. There­fore, HDL pro­vides the impor­tant ben­e­fit of help­ing to keep the blood ves­sels open.

“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,” said senior study author Montser­rat Fitó, coor­di­na­tor of the Car­dio­vas­cu­lar Risk and Nutri­tion Research Group at the Hos­pi­tal del Mar Med­ical Research Insti­tute in Barcelona and at the Ciber of Phys­iopathol­ogy of Obe­sity and Nutri­tion (CIBEROBN), Spain. ​“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.”

Since the func­tional prop­er­ties of HDL are so valu­able, researchers pur­posed to deter­mine what type of diet would enhance them. With this intent, they ran­domly chose 296 peo­ple at high risk of car­dio­vas­cu­lar dis­ease who were par­tic­i­pat­ing in the PREDIMED (PRE­ven­ción con DIeta MEDiter­ránea) study.

The indi­vid­u­als, whose age aver­aged 66, were assigned to one of the fol­low­ing three diets for a year:

• A tra­di­tional Med­Diet aug­mented with 4 table­spoons of vir­gin olive oil per day
• A tra­di­tional Med­Diet aug­mented with a hand­ful of nuts per day
• A healthy con­trol diet that decreased intake of red meat, sweets, processed food and high-fat dairy prod­ucts

Both Med­Di­ets empha­sized the con­sump­tion of fruits, veg­eta­bles, legumes and whole grains, as well as included mod­er­ate amounts of fish and poul­try. Blood tests to mea­sure HDL and LDL were con­ducted at the begin­ning and end of the study.

Analy­sis of the find­ings showed only the con­trol diet low­ered total and LDL cho­les­terol. Although none of the diets boosted the lev­els of HDL sig­nif­i­cantly, both Med­Di­ets improved its func­tion­al­ity. More­over, the mag­ni­tude of this ben­e­fit was much larger among those who were on the Med­Diet with the extra amount of vir­gin olive oil.

The Med­Diet enriched with olive oil resulted in the func­tional HDL improve­ments below:

• Enhance­ment of the process by which HDL removes cho­les­terol from plaque in the arter­ies and sends it to the liver
• Increased pro­tec­tion against LDL’s harm­ful action of stim­u­lat­ing plaque devel­op­ment
• Boosted relax­ation of blood ves­sels, which kept them more open for the flow of blood

Because the extra quan­tity of olive oil was asso­ci­ated with the ben­e­fits in the study, it under­scored the stark con­trast between healthy and non-healthy fat. ​“This study helps to seal in the idea that all fats should not be con­sid­ered equal,” Weston Childs, doc­tor of osteo­pathic med­i­cine in Gilbert, Ari­zona, told Olive Oil Times. ​“We know from stud­ies that most cook­ing oils on the mar­ket cause inflam­ma­tion and lipid dys­reg­u­la­tion by virtue of their effects on the omega 3:6 fatty acid ratio. The find­ing that a cold pressed oil, such as vir­gin olive oil, improved HDL func­tions shows the body metab­o­lizes these fats very dif­fer­ently.”

As the con­trol diet was rich in fruits and veg­eta­bles, like the Med­Di­ets, the researchers were sur­prised it reduced the anti-inflam­ma­tory prop­er­ties of HDL. A decline in this func­tion is linked to car­dio­vas­cu­lar dis­ease. Par­tic­i­pants on both Med­Di­ets didn’t have a reduc­tion in this area, the authors wrote.

“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,” con­cluded Fito. The study was pub­lished in the Amer­i­can Heart Association’s jour­nal Cir­cu­la­tion.

• Cir­cu­la­tion


• Amer­i­can Heart Asso­ci­a­tion