Mapping the Polyphenols of Greek EVOOs for Healthy Aging

A new study cat­e­go­rized the extra vir­gin olive oils of Greece accord­ing to their load of polyphe­nols and fur­ther explored the effects of oleo­can­thal and olea­cein on live organ­isms.

The study cor­re­lated polyphe­nols to healthy aging and also deter­mined which cul­ti­vat­ing method and pro­cess­ing pro­ce­dure gives the best results in terms of yield­ing oils richer in polyphe­nols.

The researchers from the University of Athens and the University of Innsbruck, Austria, exam­ined 134 extra vir­gin olive oils in total, focus­ing on their antiox­i­dant com­po­nent, the polyphe­nols (also called bio­phe­nols), and specif­i­cally oleo­can­thal and olea­cein.

Despite their low pres­ence in olive oil of only about five per­cent, polyphe­nols have long attracted the atten­tion of sci­en­tists due to their strong antiox­i­dant and anti-inflam­ma­tory prop­er­ties and hypo­glycemic action.

And as the researchers noted, the plethora of the exist­ing stud­ies on bio­phe­nols is not enough to uncover all the ingre­di­ents of olive oil and their effects on human health, mainly due to the fact that olive oil is not a nat­ural sub­stance, but the prod­uct of a milling process, mean­ing it requires extended research and analy­sis.

The eval­u­ated extra vir­gin olive oil sam­ples were selected to cover all the pro­duc­ing ter­ri­to­ries of Greece, and also rep­re­sented dif­fer­ent vari­eties, cul­ti­va­tion meth­ods, and pro­cess­ing pro­ce­dures.

It was found that extra vir­gins from Crete, and espe­cially from the areas of Lasithi and Heraklion, were the rich­est in polyphe­nols. The oils com­ing from the Aegean islands were above aver­age, while the sam­ples from the rest of the coun­try were rel­a­tively low in their polyphe­nols load.

Furthermore, the extra vir­gin olive oils that were tested dif­fer­en­ti­ated from each other in the quan­tity of the var­i­ous types of phe­nols they con­tained.

“Each area had its own imprint of phe­nols,” Leandros Skaltsounis, the head researcher of the pro­gram, told the TOVIMA Science weekly pub­li­ca­tion. ​“Extra vir­gins from Messinia and Lakonia had the high­est con­cen­tra­tions of hydrox­y­ty­rosol and tyrosol. For olea­cein and oleo­can­thal, the cham­pion seems to be Crete with an aver­age of 93 mil­ligrams per kilo­gram of olive oil, when the other areas had a con­cen­tra­tion of around 47 mil­ligrams per kilo­gram.”

The pro­ce­dures used to process the olive dru­pes were also exam­ined, and the results showed that the two-phase pro­cess­ing method is supe­rior to the three-phase when it comes to bet­ter pre­serv­ing the phe­nols load.

The water added dur­ing the malax­a­tion in the three-phase pro­cess­ing, the researchers explained, partly strips the oil of its ben­e­fi­cial com­pounds by sweep­ing away some of the polyphe­nols with waste water.

The study was also the first to shed light on the effect of cul­ti­va­tion prac­tices on the polyphe­nols in olive oil. It was deduced that inte­grated cul­ti­va­tion yields olive oils with the high­est level of polyphe­nols, fol­lowed by the organic and then con­ven­tional cul­ti­va­tion.

An inte­grated cul­ti­va­tion is a type of sus­tain­able farm­ing with a holis­tic approach to grow­ing olive trees and pro­cess­ing the olives by tak­ing into account all the rel­e­vant para­me­ters, like the qual­ity of the pro­duced olive oil, the fer­til­iz­ers used, the amount of water spent for irri­ga­tion, the energy required and much more.

After map­ping the extra vir­gin olive oils of Greece accord­ing to their pack of polyphe­nols, the study was stretched to test the effects of oleo­can­thal and olea­cein in live cells, first by inject­ing them into human skin fibrob­lasts and then to a num­ber of flies of the Drosophila strain.

It was found that the addi­tion of the sub­stances in the human cells and the live flies had results that sig­nif­i­cantly pro­moted healthy aging by increas­ing their triglyc­erides, and also by improv­ing their inflam­ma­tory sta­tus. At the same time, it reduced the oxida­tive stress of the flies and slowed down their mobil­ity deple­tion, which is an impor­tant index of aging.

“We can­not fight aging with our exist­ing level of tech­nol­ogy, but there are many pos­si­bil­i­ties of trans­lat­ing the results towards the so-called ​‘healthy aging,’ which is old age free of dis­ease,” said Ioannis Tsougakos, one of the researchers.

“We tried to extend the life of the pro­tec­tive mech­a­nisms of live organ­isms that fight toxic mol­e­cules, as these mech­a­nisms tend to under-func­tion in old age,” he added.

The researchers also cre­ated a trans­genic model of Drosophila that imi­tated obe­sity and Type 2 dia­betes of humans. They dis­cov­ered that by enrich­ing the food of the trans­genic flies with oleo­can­thal and olea­cein, they could extend their expected lifes­pan.

“The next stage is to fur­ther study the inter­ven­tion mech­a­nism that the sub­stances use at a mol­e­c­u­lar level, and reaf­firm our find­ings using more in vivo mod­els,” Tsougakos said. ​“We also con­sider design­ing a pre­lim­i­nary clin­i­cal study on healthy peo­ple and even on obese and dia­betic peo­ple.”

• Journal of Food and Chemical Toxicology


• TOVIMA Science