Biophenols in Extra Virgin Olive Oil Linked to Improved Outcomes in Obesity and Prediabetes

New research sug­gests that con­sum­ing extra vir­gin olive oil rich in oleo­can­thal and olea­cein can improve the health of peo­ple with obe­sity and pre­di­a­betes.

The study, pub­lished in Clinical Nutrition, found that con­sum­ing extra vir­gin olive oil rich in the bio­phe­nols for one month increased blood antiox­i­dant defenses and decreased para­me­ters asso­ci­ated with oxida­tive stress and inflam­ma­tion, under­ly­ing con­di­tions of both pre­di­a­betes and obe­sity.

These ben­e­fits were not observed after the con­sump­tion of non-vir­gin olive oil – a mix­ture of refined olive oil and some vir­gin olive oil – over the same period.

Known as the APRIL (Aove in PRedIabetes) study, 91 par­tic­i­pants from Málaga, Spain, aged 40 to 65, with obe­sity and pre­di­a­betes were divided into two groups.

One group of par­tic­i­pants con­sumed the bio­phe­nol-rich extra vir­gin olive oil, while the other group con­sumed the non-vir­gin olive oil for 30 days. After a washout period of 15 days, each group received the other type of oil and con­sumed it for another 30 days. Both oils were con­sumed cooked and raw, but the exact amount of con­sump­tion was not mea­sured.

“The main find­ing was the changes in oxida­tive stress,” Francisco-Javier Bermúdez-Silva, the study’s cor­re­spond­ing author and senior researcher at the Regional Hospital of Málaga, told Olive Oil Times. ​“We found a bet­ter antiox­i­dant pro­file and detected a decrease in some enzymes that are rel­e­vant for oxida­tive stress.”

“Lipid per­ox­i­da­tion is a com­mon fea­ture of oxida­tive stress, and we found that these peo­ple had less oxi­da­tion of their lipids in the blood,” he added. ​“This is in line with all the pre­vi­ous basic research that had been done with these polyphe­nols.”

In the study, the researchers wrote that three key com­pounds that reduce inflam­ma­tion increased after con­sum­ing the extra vir­gin olive oil, ​“sug­gest­ing a higher capac­ity to mod­u­late sys­temic inflam­ma­tion when com­pared to olive oil.”

“Oleocanthal and olea­cein could be medi­at­ing this lat­ter effect because their anti-inflam­ma­tory actions are well-doc­u­mented,” the researchers added.

Obesity is a con­di­tion where there is low-grade inflam­ma­tion and also oxida­tive stress. While there is still some dis­agree­ment, Bermúdez said there is a grow­ing con­sen­sus that oxida­tive stress pre­cedes the devel­op­ment of inflam­ma­tion.

“This low-grade inflam­ma­tion is related to insulin resis­tance,” he said. ​“Insulin resis­tance is related to fail­ing the beta cells to pro­duce enough insulin, and this leads to hyper­glycemia and later to a state in which the body can­not con­trol glu­cose lev­els in the blood.”

“The oxida­tive stress and inflam­ma­tion are boost­ing all of these dis­eases,” Bermúdez added. ​“If you con­sume these com­pounds in extra vir­gin olive oil, we hypoth­e­sized that you can improve your con­di­tion and pre­vent the devel­op­ment of dia­betes. To some extent, this is what we found.”

However, Bermúdez acknowl­edged sev­eral lim­i­ta­tions to the study that should be improved with fur­ther research, includ­ing the smaller-than-expected sam­ple size and rel­a­tively short time frame, which pre­vented researchers from fol­low­ing the clin­i­cal evo­lu­tion of the patients.

“If we could fol­low these patients for longer, I guess that we would find less dia­betes, less obe­sity and bet­ter gen­eral health,” he said.

Mitigating the impacts of obe­sity and pre­di­a­betes is a ris­ing pri­or­ity for researchers glob­ally as rates of both dis­eases con­tinue to climb with no signs of let­ting up.

According to a recent report pub­lished by the World Obesity Atlas, no coun­try reported a decline in obe­sity preva­lence in 2023. The inter­na­tional non-gov­ern­men­tal orga­ni­za­tion esti­mates that more than 4 bil­lion peo­ple will be over­weight or obese by 2035, com­pared with 2.6 bil­lion in 2020.

While pre­di­a­betes is noto­ri­ously hard to diag­nose due to a dearth of phys­i­cal symp­toms, sep­a­rate research from Johns Hopkins University con­cluded that the global bur­den of pre­di­a­betes is sub­stan­tial and grow­ing, with more than 1 bil­lion peo­ple expected to be pre­di­a­betic by 2040.

Along with decreases in oxida­tive stress, researchers also observed a sig­nif­i­cant decrease in body weight of about one kilo­gram and body mass index after one month of con­sum­ing extra vir­gin olive oil but not non-vir­gin olive oil. They also observed a par­al­lel improve­ment in fast­ing glu­cose.

However, the researchers added that they did not observe changes in insulin resis­tance, lipid pro­file, blood pres­sure or renal func­tion.

“Taken together, these find­ings sug­gest that extra vir­gin olive oil was able to induce some clin­i­cal improve­ment in glu­cose han­dling, prob­a­bly related with body weight decrease and ame­lio­ra­tion of the inflam­ma­tory and oxida­tive sta­tus,” the researchers wrote.

“This was really a sur­prise for us,” Bermúdez added. ​“In one month, we did­n’t expect to see a change in body weight or a change in glycemia, but these are very good indi­ca­tors of good clin­i­cal results for these types of patients.”

Bermúdez added that he is work­ing on a new study to deter­mine how oleo­can­thal and olea­cein con­sump­tion may affect peo­ple with dia­betes.

“We have a new project in mind in which we plan to per­form a sim­i­lar study, but on peo­ple with dia­betes,” he con­cluded. ​“Our study has shed some light on the pre­ven­tion side of this com­pound. Now what we want to do is to per­form a more ther­a­peu­tic study by see­ing what is hap­pen­ing in peo­ple who are already dia­betic.”