Extra Virgin Olive Oil Limits the Peroxidative Effect of Meat Lipids

Summary

Italian researchers found that adding low con­cen­tra­tions of extra vir­gin olive oil to grilled turkey breast meat meals reduced lipid hydroper­ox­ides dur­ing diges­tion, while higher con­cen­tra­tions led to an unex­pected increase in lipid hydroper­ox­ides. The phe­no­lic com­po­si­tion of extra vir­gin olive oil, par­tic­u­larly hydrox­y­ty­rosol-deriv­a­tives, plays a sig­nif­i­cant role in its impact on lipid per­ox­i­da­tion dur­ing diges­tion, high­light­ing the impor­tance of study­ing the phe­no­lic com­po­si­tion of antiox­i­dant-rich foods to under­stand their effects on health.

Oxidative prod­ucts cre­ated dur­ing cook­ing and gas­tro-intesti­nal diges­tion are asso­ci­ated with adverse health con­se­quences. Lipid per­ox­i­da­tion is asso­ci­ated with free rad­i­cal pro­duc­tion and age-related dis­ease.

Italian researchers con­ducted in vitro stud­ies to shed light on the role of extra vir­gin olive oil and its phe­no­lic com­po­si­tion in lim­it­ing the per­ox­ida­tive phe­nom­ena on meat lipids dur­ing diges­tion.

The results showed an inter­est­ing para­dox: The effects on meat lipids dur­ing diges­tion dif­fered based on the amount of extra vir­gin olive oil and its phe­no­lic com­po­si­tion.

When grilled turkey breast meat meals were sup­ple­mented with a low con­cen­tra­tion (2.5 per­cent) of extra vir­gin olive oil respec­tive to meat, researchers observed sig­nif­i­cant reduc­tions of lipid hydroper­ox­ides.

During gas­tric diges­tion, gen­er­a­tion of lipid hydroper­ox­ides were reduced by 59.9 per­cent. The lev­els fur­ther dropped to near zero at the end of pan­cre­atic diges­tion.

Advanced lipox­i­da­tion end prod­ucts (thio­bar­bi­turic acid-reac­tive sub­stances or TBA-RS) aver­aged 34 per­cent inhi­bi­tion at both the end of gas­tric diges­tion and pan­cre­atic diges­tion.

A very dif­fer­ent result emerged when extra vir­gin olive oil extracts were sub­sti­tuted at 5 per­cent and 10 per­cent con­cen­tra­tions. The researchers were sur­prised to find an unex­pected increase in the amount of lipid hydroper­ox­ides at all times of diges­tion. Yet TBA-RS pro­duc­tion was inhib­ited by the addi­tion of phe­no­lic-rich frac­tions to turkey breast meat.

Two fac­tors most likely con­tribute to the dif­fer­ences. The olive extract con­tained a par­tic­u­lar class of phe­no­lic com­pounds, hydrox­y­ty­rosol-deriv­a­tives. The sci­en­tists believe these behaved as pro-oxi­dants. At the same time, cat­alyz­ers from the meat in the diges­tive sys­tem induced the per­ox­i­da­tion of extra vir­gin olive oil fatty acids, which the authors noted, ​“was fur­ther inten­si­fied by the pro-antiox­i­dant activ­ity of extra olive oil phe­no­lic com­pounds.”

“Our find­ings sug­gest that extra vir­gin olive oil phe­no­lic com­pounds may act at dif­fer­ent lev­els,” the authors wrote. ​“Since the phe­no­lic com­po­si­tion of extra vir­gin olive oil is greatly vari­able depend­ing on the cul­ti­var and agro-cli­matic fac­tors (such as grow­ing, har­vest­ing time, sea­sonal vari­abil­ity), it is plau­si­ble that dif­fer­ent extra vir­gin olive oils with dif­fer­ent phe­no­lic com­po­si­tion (i.e. high in tyrosol-deriv­a­tive and low in hydrox­y­ty­rosol-deriv­a­tive) may have a dif­fer­ent impact on oxida­tive phe­nom­ena on lipids. Therefore, it is of para­mount impor­tance to study the phe­no­lic com­po­si­tion of antiox­i­dant-rich foods used in this type of study to bet­ter under­stand their impact on lipid per­ox­i­da­tion dur­ing the diges­tion of meat.”

• Food Research International


• U.S. National Library of Medicine