Why Extra Virgin Olive Oil Is Linked with Lower Dementia Risk, Better Brain Health

Dementia has been a com­pan­ion of old age since ancient times, but rec­og­niz­ing the mech­a­nisms respon­si­ble is only now begin­ning to emerge.

Named after German psy­chi­a­trist Alois Alzheimer, Alzheimer’s dis­ease is esti­mated to be the cause of 60 to 80 per­cent of cases of demen­tia world­wide and is inevitably fatal.

Marked by cog­ni­tive decline and mem­ory loss, the dis­ease affects ten per­cent of peo­ple over the age of 65 and 40 per­cent over the age of 80.

While deaths from dis­eases such as stroke and heart dis­ease have been decreas­ing since 2001, age-stan­dard­ized demen­tia mor­tal­ity rates have risen over the same period.

There are cur­rently more than 55 mil­lion Alzheimer’s cases world­wide, and this fig­ure is expected to triple by 2050 as both pop­u­la­tion and life expectancy increase.

Although numer­ous exper­i­men­tal treat­ments for the dis­ease are in devel­op­ment, most research is focused on pre­ven­tion.

Numerous stud­ies have demon­strated that con­sum­ing extra vir­gin olive oil is linked to improved cog­ni­tive func­tion and reduced risk of demen­tia.

In a recently pub­lished cohort study of 92,383 United States adults observed over 28 years, con­sum­ing more than seven grams of olive oil per day was asso­ci­ated with a 28 per­cent lower risk of demen­tia-related death than never or rarely con­sum­ing olive oil.

Unlike those of many pre­vi­ous stud­ies, these results were found to be irre­spec­tive of gen­eral diet qual­ity.

Polyphenols dis­rupt plaque accu­mu­la­tion and mit­i­gate inflam­ma­tion

Polyphenols are a group of nat­ural com­pounds found in plants, includ­ing olives, known for their antiox­i­dant prop­er­ties.

They have var­i­ous health ben­e­fits, includ­ing poten­tial pro­tec­tion against car­dio­vas­cu­lar and neu­rode­gen­er­a­tive dis­eases.

Extra vir­gin olive oil is renowned for its rich polyphe­nol con­tent, which pro­vides most of its health ben­e­fits and con­tributes to its unique fla­vor and aroma.

Extra vir­gin olive oil con­tains 25 polyphe­nols, includ­ing oleo­can­thal, olea­cein, oleu­ropein and hydrox­y­ty­rosol.

Of these, oleo­can­thal and oleu­ropein are the most strongly asso­ci­ated with the pre­ven­tion and mit­i­ga­tion of neu­rode­gen­er­a­tive dis­eases such as Alzheimer’s. Current research sug­gests that there are mul­ti­ple ways in which this occurs.

Oleuropein agly­cone (an oleu­ropein com­pound) can induce autophagy, a nat­ural process that elim­i­nates clumps of pro­teins and dam­aged organelles (cell com­po­nents) and stops them from accu­mu­lat­ing. Two pro­teins in par­tic­u­lar are asso­ci­ated with this type of accu­mu­la­tion in forms of demen­tia, such as Alzheimer’s.

Amyloid-beta pre­cur­sor pro­tein is impli­cated in var­i­ous bio­log­i­cal func­tions, from the for­ma­tion and repair of synapses to hor­mone reg­u­la­tion. It also forms amy­loid-beta, which is toxic to neu­rons.

Amyloid-beta read­ily accu­mu­lates, form­ing small clus­ters called oligomers and even­tu­ally accu­mu­lat­ing into bulky amy­loid plaques.

These accu­mu­la­tions are dan­ger­ous for sev­eral rea­sons. They can trig­ger inflam­ma­tion through an immune response and may also induce the pro­duc­tion of abnor­mal tau pro­tein.

Tau pro­tein is essen­tial to main­tain­ing the cor­rect struc­ture of neu­rons. However, when tau pro­tein mol­e­cules become dam­aged, they can detach and form clus­ters known as neu­rofib­ril­lary tan­gles. When this hap­pens, neu­ron death fol­lows, dis­rupt­ing the trans­mis­sion of mes­sages within the brain.

Autophagy defi­ciency has been dis­cov­ered in Alzheimer’s patients, as have ele­vated lev­els of amy­loid oligomers and plaques and neu­rofib­ril­lary tan­gles.

Therefore, oleu­ropein’s abil­ity to induce this process is poten­tially an impor­tant mech­a­nism by which extra vir­gin olive oil can pro­tect against neu­rode­gen­er­a­tion.

Amyloid plaque is also present in the brains of older adults who do not develop Alzheimer’s, imply­ing that there is more than one fac­tor at play.

Neuroinflammation, the acti­va­tion of glial cells, such as microglia and astro­cytes, which hold neu­rons in place and aid their nor­mal func­tion, is a strong can­di­date.

The acti­va­tion of these cells causes the pro­duc­tion of inflam­ma­tory fac­tors such as cytokines and chemokines, which have been observed sur­round­ing plaques and impaired neu­rons in the brains of Alzheimer’s patients.

Phenolic com­pounds found in extra vir­gin olive oil, such as hydrox­y­ty­rosol and oleu­ropein, have demon­strated the abil­ity to impede the translo­ca­tion of nuclear fac­tor kappa B (NFkB) into the nucleus, lead­ing to dimin­ished pro­duc­tion of pro-inflam­ma­tory agents and thus curb­ing neu­roin­flam­ma­tion dri­ven by microglia.

Moreover, these com­pounds have been observed to enhance the secre­tion of anti-inflam­ma­tory cytokines while sup­press­ing the pro­duc­tion of pro-inflam­ma­tory cytokines, pre­sent­ing a mul­ti­fac­eted approach to com­bat­ing neu­roin­flam­ma­tion.

MUFAs linked with bet­ter brain healthvia the car­dio­vas­cu­lar sys­tem

In addi­tion to its high polyphe­nol con­tent, olive oil is rich in monoun­sat­u­rated fatty acids (MUFAs).

The famous Seven Countries Study dis­cov­ered that dif­fer­ent fats could have very dif­fer­ent effects on health. The study revealed that peo­ple in Greece and other parts of the Mediterranean enjoyed a low rate of heart dis­ease despite a high-fat diet.

The researchers con­cluded that this was because the pri­mary fats in their diet were not the sat­u­rated ani­mal fats com­mon in coun­tries with higher rates of heart dis­ease but the monoun­sat­u­rated fats of olive oil.

Strong evi­dence exists link­ing car­dio­vas­cu­lar dis­ease and Alzheimer’s, so reduc­ing the for­mer is one of many strate­gies seen as essen­tial to pre­ven­tion.

The replace­ment of sat­u­rated fats with monoun­sat­u­rated fatty acids such as oleic acid has a proven track record in this area. Oleic acid is the major com­po­nent of olive oil, con­sti­tut­ing 70 to 80 per­cent.

In addi­tion to help­ing to reg­u­late immune func­tion, research has shown that when it is used to replace dietary sat­u­rated fat, monoun­sat­u­rated fat reduces the risks of car­dio­vas­cu­lar dis­ease by decreas­ing lev­els of blood lipids such as cho­les­terol.

It has also been demon­strated that increas­ing and decreas­ing the lat­ter in human blood serum improves the HDL (high-density lipopro­tein) to LDL (low-density lipopro­tein) ratio.

One sig­nif­i­cant way in which car­dio­vas­cu­lar dis­ease may con­tribute to the devel­op­ment of demen­tia is through the dete­ri­o­ra­tion of the blood-brain bar­rier. This bar­rier refers to the spe­cial­ized prop­er­ties of the cen­tral ner­vous system’s vas­cu­lar sys­tem that con­trol the exchange of ions, mol­e­cules and cells between the blood and the brain.

When it becomes dys­func­tional, the blood-brain bar­rier can allow toxic mol­e­cules into the brain and impair the elim­i­na­tion of toxic sub­stances such as amy­loid-beta and abnor­mal tau pro­teins.

This can lead to increased neu­roin­flam­ma­tion and oxida­tive dam­age, which has also been linked to Alzheimer’s.

Research has found that the reg­u­lar con­sump­tion of extra vir­gin olive oil reduces the per­me­abil­ity of the blood-brain bar­rier in the hip­pocampi and sur­round­ing area, thus help­ing to restore nor­mal func­tion.

EVOO and the Mediterranean diet

Multiple stud­ies have con­cluded that adher­ence to the Mediterranean diet cor­re­sponds to a reduced risk of demen­tia, includ­ing Alzheimer’s dis­ease.

A 2023 cohort study from the United Kingdom Biobank found that the higher an individual’s adher­ence, the lower their risk of devel­op­ing demen­tia. Strikingly, this was found to be true regard­less of genetic pre­dis­po­si­tion.

A sep­a­rate 2023 U.S. study found that lev­els of five micronu­tri­ents com­mon in the Mediterranean diet were sig­nif­i­cantly lower in the brains of those who had died with Alzheimer’s dis­ease than those who had died with­out it.

The study ana­lyzed the brains of 31 donors whose aver­age age at death was 75 and found that the brains of those with the dis­ease had around half the lev­els of lycopene, retinol, lutein, zeax­an­thin and vit­a­min E.

Although the body only needs these sub­stances in small amounts, they are cru­cial to main­tain­ing many bod­ily sys­tems, such as the immune sys­tem, the eyes and the skin.

Mediterranean coun­tries are his­tor­i­cally among the health­i­est coun­tries in the world, record­ing rel­a­tively low rates of car­dio­vas­cu­lar dis­eases and can­cer, as well as longer life expectancy.

On the purely dietary front, the Mediterranean diet is based on the daily con­sump­tion of fruits, veg­eta­bles, legumes, nuts, whole grains and some dairy, with extra vir­gin olive oil serv­ing as the pri­mary source of fat.

The Spain-based Mediterranean Diet Foundation, one of the most influ­en­tial orga­ni­za­tions ded­i­cated to research­ing and pro­mot­ing the Mediterranean diet, defines the diet as a way of life. In the foundation’s view, lifestyle and val­ues form a vital part that can not be sep­a­rated from the whole.

This is reflected in its Mediterranean diet pyra­mid. Unlike more famil­iar food pyra­mids, the base is built from a com­bi­na­tion of exer­cise, rest, social­iz­ing, and cook­ing on the phys­i­cal front and a com­mit­ment to sus­tain­able, local, sea­sonal and eco-friendly food choices on the value front.

While more research is needed to deter­mine how the Mediterranean diet helps the body avoid and com­bat so many dis­eases, its ben­e­fits to human health are already firmly estab­lished.