Olive Oil and Infection

Dozens of phe­no­lic com­pounds have been iden­ti­fied in extra vir­gin olive oil (EVOO), each with their own unique health ben­e­fits. One of the ben­e­fits of these com­pounds is they have high bioavail­abil­ity, exten­sive research report­ing the anti-inflam­ma­tory, antimi­cro­bial, antibac­te­r­ial and antivi­ral prop­er­ties obtained from these com­pounds.

Infections or infec­tious dis­eases are caused by viruses, bac­te­ria, par­a­sites, fungi and var­i­ous other dis­ease caus­ing agents. Once an infec­tion is con­tracted, the human body relies on the immune sys­tem to fight the infec­tion through a range of cel­lu­lar, inflam­ma­tory, and immune reac­tions. Although there are med­ica­tions to treat infec­tion, nat­u­rally derived food sources such as EVOO also show promise in pre­vent­ing and treat­ing infec­tion also.

Early in vitro stud­ies showed that sev­eral polyphe­nols in olive oil have antibac­te­r­ial prop­er­ties against human pathogens, par­tic­u­larly oleu­ropein, tyrosol, and hydrox­y­ty­rosol. In a 5 minute room tem­per­a­ture test, hydrox­y­ty­rosol, and tyrosol decreased the activ­ity of Listeria mono­cy­to­genes, the bac­te­ria con­tracted from con­t­a­m­i­nated food that causes the bac­te­r­ial infec­tion known as Listeriosis.

Decarboxymethyl eleno­lic acid (EDA), p‑HPEA-EDA, and 3,4‑DHPEA-EDA have been shown to have greater antimi­cro­bial activ­ity than the com­mer­cial dis­in­fec­tants glu­taralde­hyde and ortho- phtha­lalde­hyde. The phe­no­lic com­pound oleo­can­thal has been shown to inhibit the growth of Helicobacter pylori bac­te­ria, a bac­te­ria asso­ci­ated with pep­tic ulcer and gas­tric can­cer devel­op­ment.

Hydroxytyrosol and oleu­ropein have been shown to have antivi­ral activ­ity in a dose-depen­dent man­ner. They were shown to inhibit the main viral fus­ing pro­tein in human immun­od­e­fi­ciency virus (HIV)-1 tar­get cells. Hydroxytyrosol has been shown to dis­rupt the influenza virus. Oleuropein has been shown to have anti-hepati­tis B activ­ity.

Although all of the above ben­e­fits have been dis­cov­ered, these effects have only been demon­strated through in vitro stud­ies at this stage. However, there have also been sev­eral ani­mal and human stud­ies that do show the ben­e­fits of EVOO for infec­tion.

In rab­bits, acute pyelonephri­tis, a kid­ney infec­tion caused by bac­te­ria was induced. Doses of 21 mg oleu­ropein were injected to the ani­mals. Oleuropein alone or in con­junc­tion with reg­u­lar kid­ney infec­tion med­ica­tions pro­longed the rab­bits sur­vival.

In recent times, researchers have begun to under­stand the role of intesti­nal microor­gan­isms (gut microbes) in the over­all health of the immune sys­tem. Therefore, pro­tec­tion against the growth of cer­tain microor­gan­isms can help in the treat­ment of some infec­tious dis­eases.

Because the skin of preterm infants is not com­pletely devel­oped, they are par­tic­u­larly vul­ner­a­ble to skin infec­tions due to highly path­o­genic microor­gan­isms. Therefore, alter­ing the skin micro­biota could reduce infec­tions and pro­vide addi­tional ben­e­fits. A case-con­trol study, pub­lished in Early Human Development, 2010, aimed to inves­ti­gate if olive oil (OO) appli­ca­tion could influ­ence the skin’s micro­biota com­po­si­tion. Thirty-five very low birth weight infants were ran­dom­ized to either daily skin appli­ca­tion of olive oil or rou­tine skin care for the first two weeks of life. A vari­ety of bac­te­ria were eval­u­ated with both appli­ca­tions show­ing ben­e­fi­cial results. Though no sig­nif­i­cant dif­fer­ences were estab­lished between OO or a reg­u­lar skin­care rou­tine, what the study showed is that OO is just as effec­tive and is also well tol­er­ated by preterm infants as a pre­bi­otic enhanc­ing agent.

A study, pub­lished in Journal of Nutritional Biochemistry, 2016, estab­lished that changes in gut microbes in sub­jects with meta­bolic syn­drome had immune enhanc­ing effects. The authors con­clud­ing that ​“the con­sump­tion of a Mediterranean diet increased the abun­dance of the Bacteroides genus mem­ber B. thetaio­taomi­cron and F. praus­nitzii, which sug­gest that the con­sump­tion of this diet may increase or main­tain a micro­biota with anti­in­flam­ma­tory capa­bil­ity.”

A pres­sure ulcer is a skin lesion, an infected wound that is pro­duced sec­ondary to inad­e­quate blood sup­ply to the area. Pressure ulcers are a com­mon skin issue in immo­bi­lized patients. In a study, pub­lished in the PLOS ONE, 2015, researchers dis­cov­ered that top­i­cal appli­ca­tion of EVOO is a more cost-effec­tive alter­na­tive for treat­ing pres­sure ulcers in immo­bi­lized patients with the same ben­e­fi­cial out­comes as com­monly used HOFA skin care prod­ucts.

Fatty acids, also known as dietary lipids, are also involved in the mod­u­la­tion of the immune sys­tem and inflam­ma­tory processes. Oleuropein agly­cone inhibits the proin­flam­ma­tory mol­e­cule TNF‑a. Hydroxytyrosol has been shown to reduce TNF‑a and interleukin‑1 beta with promis­ing effects on other key proin­flam­ma­tory mol­e­cules. Tyrosol has been shown to inhibit COX‑2. And oleo­can­thal has exten­sive research sur­round­ing its anti-inflam­ma­tory ben­e­fits for pre­vent­ing and treat­ing var­i­ous health con­di­tions.

A ran­dom­ized, sin­gle-blinded study in Nutrition & Metabolism, 2015, aimed to deter­mine the effect on immune responses when replac­ing oils in a typ­i­cal American diet with EVOO for a 3 month period. Forty-one obese or over­weight sub­jects were ran­dom­ized to EVOO or a mix­ture of corn, soy­bean oil and but­ter (CON). The EVOO group saw decreases in blood pres­sure, increases in HDL cho­les­terol lev­els, and in direct rela­tion to the immune sys­tem, increased anti-CD3/anti-CD28 stim­u­lated T cell pro­lif­er­a­tion, show­ing clear immuno­log­i­cal health ben­e­fits.

Overall, the results of both in vitro and in vivo stud­ies show that OO is ben­e­fi­cial for var­i­ous infec­tions and infec­tious dis­eases. Best of all, it’s a nat­ural food source that is read­ily avail­able to every­one and comes with no side effects.

• Olive Oil and Infection


• Current Opinion in Biotechnology


• Early Human Development


• Journal of Nutritional Biochemistry


• PLOS ONE


• Nutrition & Metabolism