Chemistry and Health of Olive Oil Phenolics

Abstract

The Mediterranean diet is associated with a lower incidence of atherosclerosis, cardiovascular disease, and certain types of cancer. The apparent health benefits have been partially attributed to the dietary consumption of virgin olive oil by Mediterranean populations. Most recent interest has focused on the biologically active phenolic compounds naturally present in virgin olive oils. Studies (human, animal, in vivo and in vitro) have shown that olive oil phenolics have positive effects on certain physiological parameters, such as plasma lipoproteins, oxidative damage, inflammatory markers, platelet and cellular function, and antimicrobial activity. Presumably, regular dietary consumption of virgin olive oil containing phenolic compounds manifests in health benefits associated with a Mediterranean diet. This paper summarizes current knowledge on the physiological effects of olive oil phenolics. Moreover, a number of factors have the ability to affect phenolic concentrations in virgin olive oil, so it is of great importance to understand these factors in order to preserve the essential health promoting benefits of olive oil phenolic compounds.

Fontes vegetais naturais de antioxidantes

“…19 Assim, apesar de não haver comprovação científica definitiva, é prudente e aconselhável, em termos de saúde pública, aumentar o consumo de alimentos vegetais 19 e seguir uma dieta similar à denominada "dieta do Mediterrâneo". 20 Um dos principais aspectos relacionados ao efeito protetor desses alimentos tem sido atribuído, em parte, à presença de compostos antioxidantes, dentre os quais se destacam os compostos fenólicos, além dos bem conhecidos β-caroteno, vitamina C e vitamina E. [21][22][23] O termo antioxidante tem natureza multiconceitual. No entanto, de maneira geral e no contexto deste trabalho, 'antioxidante' pode ser definido como uma família heterogênea de moléculas naturais, que, presentes em baixas concentrações, comparativamente às biomoléculas que supostamente protegeriam, podem prevenir ou reduzir a extensão do dano oxidativo.…”

Virgin olive oil in preventive medicine: From legend to epigenetics

“…Compared with a diet rich in carbohydrates, a diet rich in oleic acid (33% of total daily calories) reduces insulin requirements, thereby improving both the lipid profile and glycemic index, without altering the levels of glycosylated hemoglobin, through the activation of the peroxisome proliferator-activated receptor gamma (or PPAR-gamma)-2 gene. This latter gene enhances the action of insulin and improves lipid metabolism and thus has a preventive effect on these diseases [59,91]. Moreover, by reducing the intake of SFA and increasing that of oleic acid (modifying the proportion of fatty acids on cell membranes), there is an improved sensitivity to insulin, without increasing its secretion, although the mechanisms involved in this phenomenon remain to be clarified [25].…”

“…Tocopherols are [30,59]. On the other hand, it is important to highlight that the quantities of vitamin E in olive oil that can be daily consumed are far below from those tested to be effective in clinical trials.…”

“…The phenolic compounds, delay atherosclerosis due to their capacity to reduce the expression of both oxidized LDL and cellular adhesion molecules at the endothelial level [16,44,58,59]. Today, the level of oxidized LDL is considered both a marker for oxidative damage and subclinical atherosclerosis as a predictive index of acute cardiovascular disease.…”

“…Oleic acid [20] Inhibition of platelet aggregation and alteration of the platelet/vascular wall, reduction of fibrinogen, factor VII and the principal suppressant of hemostasis, thereby increasing fibrinolysis Phenolic compounds [44][45][46][47][48][49] Reduction of TXB2 and LTB4 in both hyperlipaemic subjects and patients with type 2 diabetes [44,50] Chemo-protective action and improvement of the endothelium function Phenolic compounds (hydroxytyrosol and tyrosol) [44,50] Preventive action against thrombotic and microthrombotic events in patients with type 2 diabetes and hyperlipaemic subjects Hydroxytyrosol [44,50] Reduction of risks for patients with cardiac pathologies [25] Oxidation and oxidative stress Maintenance of cellular integrity and reduction of ageing High level of oleic acid and lack of excess of linoleic acid [56] Anti-inflammatory and vasodilatative action a-linolenic acid (ALA) [60] Delay of atherosclerosis Phenolic compounds [16,44,59, 60] Prevention of oxidation of cells-membrane lipids and plasma lipoproteins, reducing the risk of atherosclerosis Tocopherols [43,60] Reduced production of free radicals and prevention of damages to the cellular membrane, mitochondria, and DNA, with beneficial effects on aging and cancer risk [66,67] Inflammation Anti-inflammatory action by non-selectively inhibition of the COX-1 and COX-2 enzymes Oleocanthal [38,69] Protection against various pathological conditions (10 types of tumors including colon, stomach, breast, prostate, lung, and Alzheimer's disease) Oleocanthal [72,73,78] Obesity and diabetes Reduction of risk by inhibition of the activation of NF-kB at the cellular level Phenols, carotenoids, and tocopherols [60,92] Protective action on mitochondria, reduced production of free radicals and protection against DNA oxidation [60,…”