Article

Health effects of olive oil polyphenols: Recent advances and possibilities for the use of health claims

Cardiovascular Risk and Nutrition Research Group (CARIN), Research in Inflammatory and Cardiovascular Disorders (RICAD), Barcelona, Spain.
Molecular Nutrition & Food Research (Impact Factor: 4.6). 05/2013; 57(5). DOI: 10.1002/mnfr.201200421
Source: PubMed

ABSTRACT

The Mediterranean diet and consumption of olive oil have been connected in several studies with longevity and a reduced risk of morbidity and mortality. Lifestyle, such as regular physical activity, a healthy diet, and the existing social cohesion in Southern European countries have been recognised as candidate protective factors that may explain the Mediterranean Paradox. Along with some other characteristics of the Mediterranean diet, the use of olive oil as the main source of fat is common in Southern European countries. The benefits of consuming olive oil have been known since antiquity and were traditionally attributed to its high content in oleic acid. However, it is now well established that these effects must also be attributed to the phenolic fraction of olive oil with its anti-oxidant, anti-inflammatory and anti-microbial activities. The mechanisms of these activities are varied and probably interconnected. For some activities of olive oil phenolic compounds, the evidence is already strong enough to enable the legal use of health claims on foods. This review discusses the health effects of olive oil phenols along with the possibilities of communicating these effects on food labels.

    • "The antioxidant activity may be evaluated by chemical methods, such as DPPH, ABTS (Bendini et al., 2007) and ORAC (Ninfali et al., 2002) or by accelerated oxidation methods such as OSI (Oil Stability Index) or Rancimat test (Bendini et al., 2007; Velasco and Dobarganes, 2002). The PC of EVOO also address several biological activities (Covas et al., 2006b; Martin-Pelaez et al., 2013; Rubio et al., 2014), which principally consist in: depletion of oxidized low density lipoprotein (Covas et al., 2006a; Gimeno et al., 2007; Marrugat et al., 2004; Weinbrenner et al., 2004), increase of plasmatic antioxidant capacity (Rubio et al., 2012; Visioli et al., 2000) and antiinflammatory activity (Cicerale et al., 2010). Thanks to these and many other studies (Lopez-Miranda et al., 2010), the European Food Safety Authority (EFSA) stated the admissibility of the health claim for EVOO at two conditions: (i) the olive oil must contain at least 5 mg of hydroxytyrosol and its derivatives (e.g. the oleuropein complex and tyrosol) in 20 g, corresponding to 250 mg kg À1 of oil; (ii) the claim must be matched with indication that health benefits may be obtained by consuming 20 g of oil per day (EU, 2012). "
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    ABSTRACT: The FAO dedicated the International year 2014 to family farming, which addresses several agricultural activities, including extra-virgin olive oil (EVOO) production. In Italy, family farms (FFs) produce about 55% of EVOO, whereas 3% is produced by protected designation of origin (PDO) consortia. In this research, we compared chemical and phenolic quality parameters of 28 PDO oils and 256 FF oils. Acidity, peroxide index and UV spectroscopy indicated high quality of all FF and PDO oils. The phenolic alcohols, namely 3,4-(dihydroxyphenyl)ethanol (3,4-DHPEA or hydroxytyrosol) and p-(hydroxyphenyl)ethanol (p-HPEA or tyrosol), and the secoiridoids, that are the dialdehydic forms of decarboxymethyl elenolic acid linked to hydroxytyrosol (3,4-DHPEA-EDA) and to tyrosol (p-HPEA-EDA), respectively, the 3,4-(dihydroxyphenyl)ethanol elenolic acid (3,4-DHPEA-EA) and the p-(hydroxyphenyl)ethanol elenolic acid (p-HPEA-EA), were detected by HPLC-DAD. All PDO and FF olive oils satisfy the EU health claim conditions for phenol concentration. The relative percent of each secoiridoid derivative and phenolic alcohol resulted very similar in PDO and FF oils, with the 3,4-DHPEA-EDA as the major component. The lignans, (+)-1-acetoxypinoresinol and (+)-pinoresinol, were also evaluated, with no significant differences between the two groups of oils. Finally, the discrepancy between the total phenol assayed by the Folin–Ciocalteu reagent and the HPLC method was presented and discussed. Overall, the results point to the need to support the application of the HPLC assay for quality certification of FF oils in order to ensure proper recognition of these products as well as their more valorized market distribution.
    No preview · Article · Nov 2015 · Journal of Food Composition and Analysis
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    • "Hydroxytyrosol (HT) is the major phenolic compound in VOO in both free and conjugated form, mainly as oleuropein aglycone structures commonly named secoiridoids. HT has shown showing a wide range of biological functions, such as antioxidant, anticancer, anti-inflammatory, and neuroprotective activities, as well as having beneficial effects on the cardiovascular system [4] [5]. The potential health benefits of HT have stimulated intense research on the bioavailability and metabolism of VOO phenolic compounds, a requisite to support their potential benefits for human health. "
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    ABSTRACT: Scope: Hydroxytyrosol (HT) is the major phenolic compound in virgin olive oil (VOO) in free and conjugated forms that may exert health benefits against atherosclerosis. The native form of HT is undetectable in plasma due to an extensive first pass phase II metabolism. Therefore, it is necessary to find strategies to obtain HT metabolites and to demonstrate their protective role against the endothelial dysfunction. Methods and results: Biosynthesis of the main plasmatic HT metabolites was performed through Caco-2 cells. The bioactivity of HT and the mixture of metabolites was tested at physiological concentrations (1, 2, 5 and 10 μM) in human aortic endothelial cells (HAEC) co-incubated with TNF-α (10 ng/mL) for 18 and 24 h. After the incubations, cells and media were analyzed to test possible deconjugation of metabolites or conjugation of HT. Both HT and metabolites significantly reduced the secretion of E-selectin, P-selectin, ICAM-1 and VCAM-1, but only HT metabolites further reduced MCP-1 at 24 h. HT underwent a conjugation process after incubation leading to its main metabolites in a dose-dependent manner. Conclusion: Physiological HT metabolites, synthetized for the first time by using an intestinal cell model, might be the responsible in part for the protection against endothelial dysfunction. This article is protected by copyright. All rights reserved.
    Full-text · Article · Sep 2015 · Molecular Nutrition & Food Research
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    • "A health claim is defined as any claim that states, suggests or implies that a relationship exists between a food category, a food or one of its constituents and health (Reg. EU 432/2012; Martín-Pelá ez et al., 2013). The European Food Safety Authority (EFSA) has approved a number of health claims for olive oil on the basis of generally accepted scientific data, e.g. the claim that ''olive oil polyphenols contribute to the protection of blood lipids from oxidative stress'' (EFSA, 2010; EFSA, 2011b). "
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    ABSTRACT: Extra virgin olive oil (EVOO) is the top commercial grade of olive oil, and its fatty acid composition and minor compounds have many documented health benefits. The European Food Safety Authority (EFSA) has recently attributed some health claims to EVOO. Although numerous studies have been carried out on its production technology and nutritional effects, little is known about the composition and quality of EVOO from the retail market. Thus, our aim was to evaluate EVOOs from the Italian market by assessing their fatty acid composition, quality indices, polyphenols, tocopherol content and antioxidant activity (ABTS method) with a view to the possible application of EFSA health claims. High variability was found for phenolic compounds and tocopherols, the levels of which were significantly higher in 100% Italian labeled oils compared with European Union blends. Consumption of the recommended daily amount of EVOO would cover about 50% of the recommended daily allowance (RDA) of tocopherols, as well as the polyphenol intake recommended by EFSA. Only 3 of the 32 samples had a phenolic content above 250 ppm. Particularly high polyphenol indices were found in the samples of Italian oils covered by Protected Designations of Origin (PDOs). In conclusion, the food industry and consumers need to pay close attention to producing and choosing the best EVOO from the nutritional viewpoint.
    Full-text · Article · Feb 2015 · Journal of Food Composition and Analysis
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