Cumulative evidence using cellular, animal and human models supports that dietary Olive Oil, and particularly Virgin Oli and Extra Virgin Olive Oil (EVOO), produce a series of healthy effects in many processes related with aging.

Beneficial effects of Olive Oil consumption can be explained both on the basis of the its high MUFA content and on the healthy properties of its minor bioactive compounds.

Effects of Olive Oil components on cells can be direct, for instance due to their intrinsic antioxidant properties, or indirect, mostly due to their ability to modulate gene expression. Among the minor constituents of Virgin Olive Oil and Extra Virgin Olive Oil (EVOO) contained in its non-saponifiable fraction, secoiridoids emerge by their capacity to modulate many pathways that are relevant for the aging process.

Since this fraction is almost lost by refining procedures, EVOO should represent the best choice for healthy aging [214].

To this regards, it is very important to take into consideration that the amount of olive phenolics varies greatly, not only among different olive varieties, but also depending on the ripening phase, with an increase of some phenolics like HT and tyrosol and a decrease of others such as oleuropein aglycone with maturation [215, 216, 217, 218].

Protection of mitochondrial and nuclear DNA against oxidative stress-induced damage can be exerted directly by the antioxidants contained in Olive Oil, with Virgin Olive Oil polyphenols being particularly active. This action can be further increased by virtue of their ability to sustain endogenous antioxidant systems (both enzymatic and nonenzymatic) resulting in the attenuation of aging-related increase of lipid peroxidation in post-mitotic tissues, the most relevant tissues in aging, and contributing to the maintenance of genomic stability, particularly in the case of mitochondrial DNA.

Although a positive relationship of leukocyte telomere length and Mediterrranean diet adherence has been also reported, studies directly evaluating the effects of Olive Oil intake on leukocyte telomere length and their effects on telomerase activity are absent, which warrants further investigation.

Ethnicity may be also an important factor that must be taken into account to understand the role of Mediterrranean diet (and possibly of Olive Oil) on telomere length. Olive Oil may induce epigenetic changes both by means of its MUFA content and by its phenolic compounds.

The effect of EVOO on proteostasis is apparently age and tissue-specific. Secoiridoids enhance the expression of chaperones and are important modulators of proteostasis and nutrient sensing alterations with aging.

Research carried out by different groups with different models support the potential role that Olive Oil and particularly some of its phenolic compounds play in preventing and palliating some aging-associated diseases as diabetes. Of note, oleuropein produced antidiabetic effects in animal and cellular models and, interestingly, an olive leaf extract reproduced these effects in middle-aged overweight men, who are more prone to be insulin resistant. However, it is important to note that compounds contained in EVOO could target differentially mTOR signaling, one of the most important regulator of nutrient sensing which inhibition is associated with enhanced longevity. In this way, whereas both oleic acid and HT seem to activate mTOR signaling, oleocanthal inhibits this pathway which may be a major contributor to the healthy actions of this compound.

Mediterranean diet is also associated with improvements of cognitive decline in aging which could be related with healthy effects of oleocanthal as recognized in mice and human cell lines. Secoiridoids as oleuropein as well as other olive phytochemicals and OA also appear to exert positive actions on stem cells function and have been recognized as very important promotors of tissue regeneration both in vivo and in vitro. Finally, inflammation is another major target of Olive Oil which can be explained by the anti-inflammatory action of HT and Olive Oil secoiridoids.

Translation of these observations, particularly those involving in vitro approaches (which miss the effects of phenolic metabolites) and those using extracts or purified compounds at nonphysiological concentrations, to the actual effects of dietary Olive Oil on human aging should be carried out with caution. In addition, when investigations have been carried out with extracts, it is not possible to ascribe the observed effects to a particular compound [9]. 

In any case, the recognition that positive effects of Olive Oil are exerted on virtually all the proposed hallmarks of aging in both organisms and cellular models could help us to understand the molecular basis of health improvement, reduced risk of aging-associated diseases, and increased longevity which have been associated with consumption of a typical Mediterranean diet containing Olive Oil as the predominant fat source.

Future research on this interesting topic is clearly warranted.

SOURCE: https://pmc.ncbi.nlm.nih.gov/articles/PMC6273542/