The Role of Monounsaturated Fatty Acids in Olive Oil's Health Benefits

The excep­tional health ben­e­fits of extra vir­gin olive oil are par­tially attrib­uted to its fatty acids, par­tic­u­larly oleic acid, which com­prises 55 to 83 per­cent of the oil’s total com­po­si­tion.

Oleic acid, clas­si­fied as a monoun­sat­u­rated fatty acid (MUFA), has been exten­sively stud­ied by sci­en­tists over the last decades, con­sis­tently demon­strat­ing many pos­i­tive effects on human health.

Role of monoun­sat­u­rated fat in olive oil health ben­e­fits

Research has demon­strated that the monoun­sat­u­rated fatty acids found in olive oil can sig­nif­i­cantly enhance heart and car­dio­vas­cu­lar health, mainly by low­er­ing LDL (bad) cho­les­terol lev­els, increas­ing HDL (good) cho­les­terol lev­els and reduc­ing triglyc­erides.

Moreover, oleic acid is rec­og­nized for its anti-inflam­ma­tory prop­er­ties, fur­ther con­tribut­ing to heart health.

Additionally, pre­lim­i­nary research sug­gests that oleic acid may reduce the risk of obe­sity by induc­ing a feel­ing of full­ness, aid­ing in weight man­age­ment.

Furthermore, sev­eral stud­ies have indi­cated that reg­u­lar con­sump­tion of mod­er­ate amounts of oleic acid may play a pre­ven­tive role in demen­tia among older indi­vid­u­als.

Ongoing research also explores the poten­tial of oleic acid to inhibit the growth of cer­tain types of can­cer by sup­press­ing the expres­sion of genes asso­ci­ated with the metas­ta­sis of can­cer­ous cells.

What are MUFAs?

“Fatty acids are essen­tial com­po­nents of lipids, which are impor­tant mol­e­cules for the struc­ture and func­tion of cells,” Nuno Rodrigues, a researcher at the Centro de Investigação de Montanha (CIMO) of the Polytechnic Institute in Bragança, in Portugal, told Olive Oil Times.

The word ​“fat” in this con­text does not refer to the fat con­tent of the fatty acid but to its mol­e­c­u­lar struc­ture.

“Fatty acids are an impor­tant source of energy for the body, being stored in adi­pose tis­sue, besides play­ing essen­tial roles in the struc­ture of cell mem­branes,” Rodrigues explained.

The dif­fer­ent impacts of sat­u­rated and unsat­u­rated fatty acids lie in their dif­fer­ent inter­ac­tion with human biol­ogy.

Unsaturated fatty acids con­tain a dou­ble bond, mak­ing them prone to inter­act­ing with other mol­e­cules. 

On the other hand, sat­u­rated fatty acids (SFAs) con­tain a sin­gle bond only, which has con­se­quences for how they are digested and absorbed.

Fatty acids’ chem­i­cal struc­tures influ­ence how they are metab­o­lized and uti­lized by the body.

The chem­i­cal struc­ture of fatty acids affects the states of mat­ter of the fatty acids, impact­ing the flu­id­ity of cell mem­branes and how much they are prone to oxi­da­tion. These char­ac­ter­is­tics con­vey sig­nif­i­cantly dif­fer­ent effects on health.

Saturated fats are mostly solid at room tem­per­a­ture. Meanwhile, monoun­sat­u­rated fatty acids, which con­tain one dou­ble bond, are gen­er­ally liq­uid at room tem­per­a­ture and can be found in olive oil, other veg­etable oils and food such as avo­ca­dos and some nuts.

Polyunsaturated fatty acids (PUFAs) con­tain more than one dou­ble bond, fur­ther enhanc­ing their poten­tial to inter­act with other mol­e­cules.

PUFAs include fatty acids the human body can­not syn­the­size, such as omega‑3 and omega‑6, found in fish, flaxseeds, wal­nuts and veg­etable oils.

Similarly to MUFAs, PUFAs are also cred­ited with sev­eral health ben­e­fits, includ­ing sup­port­ing heart health and reduc­ing inflam­ma­tion.

How olive oil’s fatty acids are formed

The fatty acids in olive oil are formed at the end of the olive devel­op­ment process, essen­tially dur­ing their mat­u­ra­tion.

“In the olive tree, dur­ing the fruit’s growth, the plant pro­duces car­bo­hy­drates that are later con­verted into fatty acids through pho­to­syn­the­sis,” Rodrigues said. ​“The fatty acids are stored in the cells of the olive pulp in the form of triglyc­erides and are the main fat mol­e­cules, olive oil, present in the fruits.” 

After the olive har­vest, dur­ing the extrac­tion process, the olive oil present in the cells of the olive pulp is released and extracted.

“Olive oil is mainly com­posed of triglyc­erides, which con­sist of three fatty acids linked to a glyc­erol mol­e­cule and rep­re­sent more than 97 per­cent of the olive oil,” Rodrigues said.

The sig­nif­i­cance of olive oil fatty acid com­po­si­tion 

“Since fatty acids are the major com­po­nents of olive oil, they are also respon­si­ble for some of the most impor­tant func­tions attrib­uted to olive oil,” Rodrigues said.

According to the researcher, fatty acids are among the main con­trib­u­tors to the pos­i­tive impact olive oil can have on health.

“Compared to other oils and fats, olive oil is very rich in monoun­sat­u­rated fatty acids, between 70 and 85 per­cent of the fatty acids in olive oil, of which oleic acid is the most sig­nif­i­cant,” Rodrigues said.

“MUFAs are of great impor­tance from a nutri­tional per­spec­tive, as lipids are the main com­po­nent of our cell mem­branes,” he added. ​“Due to their greater elas­tic­ity, MUFAs con­fer less rigid­ity to cell mem­branes and thus act in the pre­ven­tion of car­dio­vas­cu­lar dis­ease.”

While olive oil con­tains all types of fatty acids, the ratio between MUFAs, PUFAs, and SFAs deter­mines its resis­tance to oxi­da­tion and shelf life.

“Fatty acids also have an impor­tant func­tion as pre­cur­sors of some volatile com­pounds, where fatty acids are essen­tial com­po­nents of the meta­bolic path­ways that form the aro­mas of olive oils,” Rodrigues said.

MUFA com­po­si­tion dif­fers among olive oils

Not all olive trees develop sim­i­lar amounts of oleic acid in their fruits. Many fac­tors impact an olive oil’s fatty acid com­po­si­tion, includ­ing the tree’s age.

“The work we have been devel­op­ing over the last decade shows that the age of the plant is a fac­tor that can affect the com­po­si­tion in fatty acids, not the fatty acids found, but the rel­a­tive amount of each of them,” Rodrigues said, point­ing to recent research pub­lished by Rodrigues and his col­leagues.

Several fac­tors can influ­ence each olive tree cul­ti­var’s com­po­si­tion of fatty acids.

“The most impor­tant and deter­mi­nant fac­tor is the cul­ti­var of ori­gin; that is, each cul­ti­var has a char­ac­ter­is­tic fatty acid com­po­si­tion,” Rodrigues said.

The International Olive Council esti­mates more than 1,000 olive tree vari­eties. Only a few hun­dred, though, are cul­ti­vated for olive oil pro­duc­tion.

“There are other impor­tant fac­tors, such as the cul­tural prac­tices the olive tree was sub­jected to, that is, whether it was pro­duced in dry farm­ing or irri­ga­tion, whether it was more or less fer­til­ized, the cli­matic con­di­tions, the cli­matic vari­a­tions, the lat­i­tude and alti­tude and also the age of the tree,” Rodrigues said.

“Some of our work shows that older trees have a higher pro­por­tion of oleic acid than younger trees of the same cul­ti­var,” he added.

Other con­tribut­ing fac­tors include the amount of sun­light dur­ing the olives’ ripen­ing or the loca­tion, as olives in colder regions tend to be richer in unsat­u­rated fatty acids.

“The ripeness of the olives at the time of har­vest can sig­nif­i­cantly affect the com­po­si­tion of fatty acids in olive oil,” Rodrigues said. ​“The stor­age con­di­tions of the olive oil, such as tem­per­a­ture and expo­sure to light and oxy­gen, can influ­ence its sta­bil­ity and com­po­si­tion. These vari­ables can inter­act in dif­fer­ent ways, result­ing in dif­fer­ent fatty acid pro­files in dif­fer­ent olive oils.”