The beneficial effects of olive oil and olive leaf extract were already known in the ancient world and have been studied and scientifically proven over the last two centuries.
Most of the interesting properties of EVO oil, from a medical point of view, can be attributed precisely to polyphenols, thanks to their antioxidant effect. The growing interest in the nature of polyphenols has led to a multitude of studies to investigate their medical efficacy. This has laid the foundation for the development of new therapies against chronic inflammatory conditions, such as atherosclerosis, cancer and age-related neurodegeneration. Today, almost 80% of olive extracts are included in the European Pharmacopoeia, including several polyphenols such as oleuropein, hydroxytyrosol, tyrosol, apigenin, caffeic acid and verbascoside.
The first two are the most abundant polyphenols in EVOO and are considered to have nutraceutical effects. These substances activate the same circuits involved in caloric restriction, particularly in muscles, adipose tissue and kidneys. The benefits of a low-calorie diet, including the extension of life expectancy and the reduction of age-related diseases, are well described and recognized in the scientific literature. However, a caloric restriction regimen can be difficult to sustain in the long term. Dietary intake of nutraceuticals that can mimic its effect, such as EVOO, could be an excellent alternative. Polyphenols, but especially oleuropein and hydroxytyrosol, lead to increased levels of sirtuins, the same family of proteins activated by caloric restriction. The result is the counterregulation of inflammation and oxidative cellular damage, the reduction of cholesterol and triglyceride synthesis and the inhibition of adipogenesis through the PPAR-gamma cellular pathway.
Some scientific studies have also suggested that oleuropein and oleocanthal, responsible for the spicy taste of EVO oil, could prevent the development of Alzheimer's disease by reducing the deposition of Beta-amyloid plaques responsible for neuronal damage. Furthermore, the signaling mechanisms activated by these two polyphenols involved in the inhibition of cellular aging have been identified.
A similar protective mechanism against cellular aging and oxidative stress also seems to underlie the antitumor effect of polyphenols, especially oleuropein and hydroxytyrosol. Studies on breast, colon, and prostate cancer cell cultures have also observed an antiproliferative and antiangiogenic action of these substances.
EVO oil also seems to have beneficial properties against atherosclerosis and cardiovascular disease. The reason is to be found in the powerful antioxidant effect of polyphenols, but mechanisms of protection against ischemia/reperfusion damage are also involved with possible reduction of the extension of the infarcted tissue, reduced lipid synthesis at the plaque level, reduced platelet aggregation and decreased blood concentrations of cholesterol and triglycerides.
