Mediterranean Diet Adherence Linked to Lower Risk of Atrial Fibrillation

A recent study pub­lished in the jour­nal Frontiers in Cardiovascular Medicine has exam­ined the cur­rent evi­dence regard­ing the impact of dietary inter­ven­tions, indi­vid­ual nutri­ents and other dietary com­po­nents on the con­di­tion.

The most com­mon car­diac arrhyth­mia, atrial fib­ril­la­tion, is char­ac­ter­ized by rapid and irreg­u­lar beat­ing of the heart’s atrial cham­bers. The con­di­tion can con­tribute to or be a pre­cur­sor of a wide range of com­pli­ca­tions, from chest pain and faint­ing to heart fail­ure and stroke.

Despite advances in med­ical pro­ce­dures and phar­ma­ceu­ti­cal treat­ments, the inci­dence of atrial fib­ril­la­tion has been increas­ing world­wide, par­tic­u­larly in the so-called devel­oped world.

For exam­ple, a major cohort study esti­mated a three per­cent increase in the United States annu­ally from 2006 to 2018. This has led to a resur­gence in inter­est in lifestyle man­age­ment, of which diet is a sig­nif­i­cant aspect.

The researchers from the car­di­ol­ogy divi­sion of Baylor Scott & White Health Hospital, Texas, used a nar­ra­tive syn­the­sis approach to explore the impact of dietary inter­ven­tions on atrial fib­ril­la­tion and to assess the role that indi­vid­ual com­po­nents of those inter­ven­tions play.

The study found that the two dietary pat­terns most com­monly asso­ci­ated with reduced inci­dences and improved out­comes were the Mediterraneanand DASH diets.

Although the lat­ter was linked to improved car­dio­vas­cu­lar out­comes and decreased mor­tal­ity, the researchers found that once other lifestyle fac­tors were con­sid­ered, there was no demon­stra­ble effect on the spe­cific inci­dence, recur­rence or pro­gres­sion of atrial fib­ril­la­tion.

On the other hand, the Mediterranean diet served as ​“a robust pre­ven­ta­tive strat­egy against the devel­op­ment of atrial fib­ril­la­tion.”

In explor­ing the poten­tial mech­a­nisms behind this effect, the researchers posited sev­eral pos­si­ble fac­tors.

The first is the Mediterranean diet’s high per­cent­age of fruits, veg­eta­bles and extra vir­gin olive oil. All three food groups pro­vide antiox­i­dants and polyphe­nols, which have proven anti-inflam­ma­tory and car­dio­pro­tec­tive effects.

Oleuropein, for exam­ple, has demon­strated a capac­ity to sig­nif­i­cantly reduce blood pres­sure, align­ing with the tra­di­tional use of olive leaf in treat­ing hyper­ten­sion.

Studies dis­cussed in the paper also pro­vide evi­dence for the anti-throm­botic and anti-arrhyth­mic prop­er­ties of oleo­can­thal and hydrox­y­ty­rosol, com­pounds found almost exclu­sively in extra vir­gin olive oil.

These com­pounds have been shown to improve endothe­lial func­tion and reduce platelet aggre­ga­tion, thereby low­er­ing the risk of events such as stroke in patients with atrial fib­ril­la­tion.

The impor­tance of olive-based com­pounds was fur­ther sup­ported by a sec­ondary analy­sis in 2014 of the PREDIMED trial, which revealed sig­nif­i­cant atrial fib­ril­la­tion pro­tec­tion from a Mediterranean diet sup­ple­mented with extra vir­gin olive oil.

The researchers cited that analy­sis, which showed a 38 per­cent reduc­tion in rel­a­tive atrial fib­ril­la­tion risk com­pared to other diets.

While the exam­ined evi­dence strongly sup­ported the role of antiox­i­dants and polyphe­nols, par­tic­u­larly regard­ing direct links to reduced atrial fib­ril­la­tion inci­dence, the researchers stress that the mech­a­nisms in ques­tion remain rel­a­tively unex­plored.

They con­clude, there­fore, that while each com­po­nent war­rants exten­sive fur­ther research, dietary inter­ven­tions such as the Mediterranean diet should be con­sid­ered holis­ti­cally in the con­text of dis­ease pre­ven­tion.

This con­clu­sion is based on the grow­ing evi­dence show­ing that the Mediterranean diet is linked to sig­nif­i­cantly reduc­ing car­dio­vas­cu­lar events and dia­betes mel­li­tus, improved blood pres­sure, insulin resis­tance, lipid pro­files and triglyc­erides, and sig­nif­i­cantly lower obe­sity rates.

• American Heart Journal