Study Reveals How Mediterranean Diet Might Counteract Covid-19

Summary

A study pub­lished in the Journal of Physiology and Biochemistry sug­gests that fol­low­ing a Mediterranean diet rich in polyphe­nols like hydrox­y­ty­rosol and resver­a­trol may help pre­vent severe Covid-19 con­se­quences such as cytokine storms by con­trol­ling inflam­ma­tion and oxida­tive stress. While the impact of these polyphe­nols on Covid-19 specif­i­cally is not yet fully proven, their antiox­i­dant and anti-inflam­ma­tory prop­er­ties could poten­tially offer pro­tec­tion against the virus, although fur­ther research is needed to con­firm these poten­tial ben­e­fits.

A new com­pre­hen­sive review study shows how fol­low­ing a Mediterranean diet and con­sum­ing extra vir­gin olive oil might pro­vide some pro­tec­tion against the worst effects of a Covid-19 infec­tion.

Some evi­dence sug­gests that fol­low­ing the tra­di­tional Mediterranean diet might help pre­vent infec­tion.

Compared to other diets, such as the Western diet, the Mediterranean diet seems capa­ble of con­tain­ing inflam­ma­tion and inhibit­ing poten­tially deadly Covid-19 con­se­quences such as cytokine storms.

The research, pub­lished by the Journal of Physiology and Biochemistry, gath­ered the avail­able data on key ele­ments of the Mediterranean diet, such as its phe­no­lic com­pounds, look­ing at their poten­tial impact in pre­vent­ing or treat­ing Covid-19 infec­tion.

“In con­trast with the poten­tial ben­e­fi­cial effects of the Mediterranean diet, Western diets are related to sys­temic inflam­ma­tion, increased oxida­tive stress and lower immune response, and thus may increase the sever­ity of Covid-19 patients,” the researchers wrote.

“These effects are due to their high con­tent of sat­u­rated fat, refined car­bo­hy­drates and sugar, and to their low con­tent of fiber,” they added.

In the intro­duc­tion of the study, the researchers pointed out how the Mediterranean diet has been cred­ited in sev­eral pre­vi­ous stud­ies with reduc­ing the risks of devel­op­ing com­mon severe con­di­tions such as meta­bolic syn­drome or car­dio­vas­cu­lar dis­ease.

“Current evi­dence sup­ports the poten­tial ben­e­fits that hydrox­y­ty­rosol, resver­a­trol, flavonols such as quercetin, fla­vanols like cat­e­chins, and fla­vanones on the order of narin­genin could have on Covid-19,” the authors wrote.

However, the sci­en­tists acknowl­edged that the impacts of these polyphe­nols com­monly found in Mediterranean diet foods on Covid-19 have yet to be proven.

Still, they wrote, ​“these bioac­tive com­pounds show bio­log­i­cal activ­i­ties that can be use­ful to pre­vent this infec­tion and or to improve its prog­no­sis.”

The researchers ana­lyzed the prop­er­ties of the polyphe­nols, such as their antiox­i­dant activ­ity, which might con­trol inflam­ma­tion and the release of free rad­i­cals.

More specif­i­cally, researchers high­lighted how hydrox­y­ty­rosol sup­presses two enzymes: Matrix metalloproteinase‑9 (MMP‑9) and Cyclo-oxy­ge­nase‑2 (COX‑2). MMP‑9 is con­sid­ered respon­si­ble for allow­ing inflam­ma­tion to spread to the lungs.

Scientists believe that MMP‑9 and COX‑2 play an active role in caus­ing the cytokine storm, one of the most deadly con­di­tions caused by Covid-19.

Hydroxytyrosol is one of the most rel­e­vant phe­nols in extra vir­gin olive oil due to its abil­ity to pro­tect blood lipids from oxida­tive stress. It is also cred­ited with antivi­ral prop­er­ties.

Researchers also observed in a lab­o­ra­tory set­ting that resver­a­trol, a polyphe­nol com­monly found in Mediterranean diet foods, has demon­strated the abil­ity to inhibit res­pi­ra­tory viruses.

One of the rea­sons for this impact is its abil­ity to trig­ger the nuclear fac­tor ery­throid 2‑related fac­tor 2 (Nrf2), which improves cel­lu­lar antiox­i­dant defenses. Both hydrox­y­ty­rosol and resver­a­trol are con­sid­ered cru­cial in mod­u­lat­ing the Nrf2 defenses.

“The acti­va­tion of Nrf2 has been pos­tu­lated as a poten­tial ther­a­peu­tic tar­get against this dis­ease since it is known to pro­tect from lung injuries such as acute lung injury or res­pi­ra­tory dis­tress syn­drome,” the researchers wrote.

The paper’s authors believe that resver­a­trol could also help pre­vent exces­sive inflam­ma­tion and result in even more ben­e­fits to patients with com­mon con­di­tions such as ath­er­o­scle­ro­sis or hyper­ten­sion.

The flavonoids found in the Mediterranean diet were also inves­ti­gated for their poten­tially ben­e­fi­cial impacts.

“The antibac­te­r­ial and anti­cancer prop­er­ties of flavonoids are widely known. Moreover, these com­pounds, com­monly found in the Mediterranean diet, have the abil­ity to sequester free rad­i­cals,” the sci­en­tists wrote.

While flavonoids might acti­vate the Nrf2 path­way and mod­u­late the inflam­ma­tory process, researchers warned that fur­ther stud­ies are needed to assess such poten­tial.

Flavonols such as quercetin might con­tribute to pre­vent­ing the acute kid­ney dam­age caused by Covid-19, the acti­va­tion of harm­ful macrophages and the pro­tec­tion of the Nrf2 fac­tor.

The inter­est in quercetin’s anti-inflam­ma­tory and antivi­ral effects is also due to its ubiq­uity in foods highly asso­ci­ated with the Mediterranean diet, includ­ing apples, grapes and onions. ​“It rep­re­sents the most abun­dant flavonoid in the human diet,” the researchers said.

In their con­clu­sions, the researchers high­lighted how the lack of evi­dence of polyphe­nols’ impact on Covid-19 should be addressed, and more stud­ies are needed.

“Nevertheless, numer­ous stud­ies have demon­strated that these mol­e­cules induce pos­i­tive effects on sev­eral alter­ations induced by this dis­ease under con­di­tions other than SARS-COV‑2 infec­tion, such as oxida­tive stress, inflam­ma­tion, and throm­bo­sis,” they wrote.

“This sci­en­tific infor­ma­tion is valu­able and sug­gests that the phe­no­lic com­pounds of the Mediterranean diet may rep­re­sent a poten­tial pro­tec­tive fac­tor against Covid-19. Still, cau­tion must be taken when con­nect­ing pre­ex­ist­ing data to this new infec­tion”, the researchers added.

“In addi­tion to the ben­e­fi­cial effects on Covid-19 out­comes medi­ated by their antiox­i­dant and anti-inflam­ma­tory effects, the Mediterranean diet polyphe­nols can also act through other mech­a­nisms that are not addressed in this review arti­cle,” they con­cluded.