Intake Of Virgin Olive Oil Research Articles

Postprandial transcriptome associated with virgin olive oil intake in rat liver

Liver has been proposed as a gatekeeper that regulates postprandial lipemia and a potential target for regulation by acute intake of virgin olive oil. To characterize the hepatic gene expression response to a fat gavage, male rats were fed a bolus of 5 ml of extra-virgin olive oil and the hepatic mRNA expression analyzed 4 hours later using DNA microarrays. To provide an initial screening of candidate genes, only twenty one with remarkably modified expression between both conditions (signal log2 ratio > 2.5 or < -2.5) were considered and confirmed by quantitative real time PCR. Those that presented biological significance were also analyzed 8 hours after the experimental approach. Hepatic A2m Slc13a5 and Nrep mRNA expressions were found significantly changed in both studied conditions and showed the highest significant associations with postprandial plasma triglycerides and lack of association with basal triglyceridemia. These results highlight new gene regulation in liver by postprandial triglyceridemia and will help to understand the complex human pathology providing the involvement of hepatic proteins and new strategies to cope with postprandial metabolism.

A Mediterranean diet rich in virgin olive oil may reverse the effects of the ‐174G/C IL6 gene variant on 3‐year body weight change

Only a few studies have analyzed the effects of the potential interaction between the -174G/C polymorphism of IL6 gene and the adherence to the Mediterranean diet (MD) on adiposity indexes. Our aim was to investigate the interplay between the -174G/C polymorphism of the IL6 gene and a Mediterranean-style diet on body weight changes after 3 years of nutritional intervention in a high cardiovascular risk population. A total of 737 participants, aged 55-80 years were assigned to a low-fat diet or to a Mediterranean-style diet group with high intake of virgin olive oil (VOO) or nuts. Anthropometric measurements were taken at baseline and after 3-year follow-up. The -174G/C polymorphism of the IL6 gene was genotyped. Minor allele frequency (C) was 0.39. At baseline, the CC genotype was associated with higher measures of adiposity. After 3 years, a significant interaction (p=0.028) was found between the polymorphism (GG+GC versus CC) and the nutritional intervention: CC subjects following the MD+VOO had the lowest body weight gain. In conclusion, at baseline, CC subjects for the -174G/C polymorphism of IL6 had the highest body weight and BMI. However, after 3 years of nutritional intervention with MD+VOO, these subjects were predicted to have the greatest reduction in body weight.

Gene expression changes in mononuclear cells in patients with metabolic syndrome after acute intake of phenol-rich virgin olive oil

BackgroundPrevious studies have shown that acute intake of high-phenol virgin olive oil reduces pro-inflammatory, pro-oxidant and pro-thrombotic markers compared with low phenols virgin olive oil, but it still remains unclear whether effects attributed to its phenolic fraction are exerted at transcriptional level in vivo. To achieve this goal, we aimed at identifying expression changes in genes which could be mediated by virgin olive oil phenol compounds in the human.ResultsPostprandial gene expression microarray analysis was performed on peripheral blood mononuclear cells during postprandial period. Two virgin olive oil-based breakfasts with high (398 ppm) and low (70 ppm) content of phenolic compounds were administered to 20 patients suffering from metabolic syndrome following a double-blinded, randomized, crossover design. To eliminate the potential effect that might exist in their usual dietary habits, all subjects followed a similar low-fat, carbohydrate rich diet during the study period. Microarray analysis identified 98 differentially expressed genes (79 underexpressed and 19 overexpressed) when comparing the intake of phenol-rich olive oil with low-phenol olive oil. Many of these genes seem linked to obesity, dyslipemia and type 2 diabetes mellitus. Among these, several genes seem involved in inflammatory processes mediated by transcription factor NF-κB, activator protein-1 transcription factor complex AP-1, cytokines, mitogen-activated protein kinases MAPKs or arachidonic acid pathways.ConclusionThis study shows that intake of virgin olive oil based breakfast, which is rich in phenol compounds is able to repress in vivo expression of several pro-inflammatory genes, thereby switching activity of peripheral blood mononuclear cells to a less deleterious inflammatory profile. These results provide at least a partial molecular basis for reduced risk of cardiovascular disease observed in Mediterranean countries, where virgin olive oil represents a main source of dietary fat. Admittedly, other lifestyle factors are also likely to contribute to lowered risk of cardiovascular disease in this region.

Effect of the long-term regular intake of virgin olive oil on the phenolic metabolites in human fasting plasma

The effect of repeated consumption of virgin olive oil on endogenous phenolic metabolites of fasting plasma is unknown. For this reason, we hypothesized that regular long-term virgin olive oil intake could have an indirect protection effect on the endogenous phenols. Thus, the aim of the study was to determine the phenolic profile of human plasma in a fasting state of long-term regular virgin olive oil consumers, using the fasting plasma of non-consumers as a natural control. Forty participants living in the area of Reus (Catalonia, Spain) were selected, 20 life-long regular consumers of virgin olive oil and a natural control of 20 non-consumers, the latter being Rumanians who dislike the taste of olive oil. The diet was obtained from 3-day food records. The results showed similar phenolic composition of fasting plasmas of the two volunteer groups. Of special interest is that more of the compounds quantified showed higher concentration in fasting plasma from habitual virgin olive oil consumers. The compounds were semi-quantified using caffeic acid as the calibration standard. The quantification of fasting consumer's plasma showed higher concentration of a hydroxyflavanone type compound (2.90 ± 0.04 μM vs 1.5 ± 0.04 μM) and a catecholamine derivative (0.70 ± 0.03 μM vs 0.56 ± 0.03 μM) than the plasma of non-consumers ( P < 0.05). The results suggest an indirect protective mechanism of long-term regular virgin olive oil consumption related to the protection of the endogenous antioxidant system.

Effects of olive oil and its fractions on oxidative stress and the liver's fatty acid composition in 2,4-Dichlorophenoxyacetic acid-treated rats

BackgroundOlive oil's beneficial effects are not only related to its high content of oleic acid, but also to the antioxidant potential of its polyphenols. In this study, we assess the effects of virgin olive oil and its fractions on 2,4-D- induced oxidative damage in the liver of rats.MethodsMale Wistar rats were randomly divided into eight groups of ten each: (C) a control group, (D) group that received 2,4-D (5 mg/kg b.w.), (D/EVOO) group treated with 2,4-D plus extra virgin olive oil, (D/OOHF) group that received 2,4-D plus hydrophilic fraction, (D/OOLF) group treated with 2,4-D plus lipophilic fraction, (EVOO) group that received only extra virgin olive oil, (OOHF) group given hydrophilic fraction and (OOLF) group treated with lipophilic fraction. These components were daily administered by gavage for 4 weeks.ResultsA significant liver damage was observed in rats treated with 2,4-D via increased serum levels of transaminases and alkaline phosphatase, hepatic lipid peroxidation and decreased hepatic antioxidant enzyme activities, namely, superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase. The liver's fatty acid composition was also significantly modified with 2,4-D exposure. However, extra virgin olive oil and hydrophilic fraction intake during 2,4-D treatment induced a significant increase in the antioxidant enzyme activities and a decrease in the conjugated dienes (CD) and thiobarbituric acid-reactive substances (TBARs) levels in the liver. The lipophilic fraction supplemented to 2,4-D- treated rats did not show any improvement in the liver oxidative status while a marked improvement was detected in the hepatic fatty acid composition of rats supplemented with olive oil and the two fractions.ConclusionWe concluded that the protective effect of olive oil against oxidative damage induced by 2,4-D is mainly related to the antioxidant potential of its hydrophilic fraction.

A 3-year Mediterranean-style dietary intervention may modulate the association between adiponectin gene variants and body weight change

Adiponectin gene variations have been associated with obesity. There are few interventional studies analyzing this association. The aim of this study was to analyze the effects of a nutritional intervention with Mediterranean-style diet and three (-4034A/C, +45T/G, and +276 G/T) adiponectin gene variants on 3-year body weight changes in high cardiovascular risk patients. A total of 737 participants, aged 55-80 at high cardiovascular risk were assigned to a low-fat diet or to a Mediterranean-style diet (MD) groups, one with high intake of virgin olive oil (VOO) and the other with high intake of nuts. Anthropometric parameters were taken at baseline and after 3-year follow-up, and the genotyping of the -4034A/C, +45T/G, and +276 G/T polymorphisms was done. GG genotype of the +45T/G polymorphism was associated with 3-year higher body weight gain (B = 1.399; B = 0.043). TT genotype of the +276G/T polymorphism was linked to the highest 3-year body weight gain in men. Both Mediterranean diets appeared to reverse this effect (p for interaction = 0.053). Adiponectin gene variation appeared to be associated with 3-year body weight changes in a high cardiovascular risk population. This association may be modulated by a nutritional intervention with a Mediterranean-style diet.

A 3 years follow-up of a Mediterranean diet rich in virgin olive oil is associated with high plasma antioxidant capacity and reduced body weight gain

The aim of this study was to analyze the influence of a Mediterranean dietary pattern on plasma total antioxidant capacity (TAC) after 3 years of intervention and the associations with adiposity indexes in a randomized dietary trial (PREDIMED trial) with high cardiovascular risk patients. 187 subjects were randomly selected from the PREDIMED-UNAV center after they completed 3-year intervention program. Participants were following a Mediterranean-style diet with high intake of virgin olive oil or high intake of nuts, or a conventional low-fat diet. Adiposity indexes were measured at baseline and at year 3. Plasma TAC was evaluated using a commercially available colorimetric assay kit. Plasma TAC in the control, olive oil and nuts groups was 2.01+/-0.15, 3.51+/-0.14 and 3.02+/-0.14 mM Trolox, respectively after adjusting for age and sex. The differences between the Mediterranean diet and control groups were statistically significant (P<0.001). Moreover higher levels of TAC were significantly associated with a reduction in body weight after 3 years of intervention among subjects allocated to the virgin olive oil group (B=-1.306; 95% CI=-2.439 to -0.173; P=0.025, after adjusting for age, sex and baseline body mass index). Mediterranean diet, especially rich in virgin olive oil, is associated with higher levels of plasma antioxidant capacity. Plasma TAC is related to a reduction in body weight after 3 years of intervention in a high cardiovascular risk population with a Mediterranean-style diet rich in virgin olive oil.

A Large Randomized Individual and Group Intervention Conducted by Registered Dietitians Increased Adherence to Mediterranean-Type Diets: The PREDIMED Study

Objective To assess the effectiveness of an intervention aimed to increase adherence to a Mediterranean diet. Design A 12-month assessment of a randomized primary prevention trial. Subjects/settings One thousand five hundred fifty-one asymptomatic persons aged 55 to 80 years, with diabetes or ≥3 cardiovascular risk factors. Intervention Participants were randomly assigned to a control group or two Mediterranean diet groups. Those allocated to the two Mediterranean diet groups received individual motivational interviews every 3 months to negotiate nutrition goals, and group educational sessions on a quarterly basis. One Mediterranean diet group received free virgin olive oil (1 L/week), the other received free mixed nuts (30 g/day). Participants in the control group received verbal instructions and a leaflet recommending the National Cholesterol Education Program Adult Treatment Panel III dietary guidelines. Main outcome measures Changes in food and nutrient intake after 12 months. Statistical analyses Paired t tests (for within-group changes) and analysis of variance (for between-group changes) were conducted. Results Participants allocated to both Mediterranean diets increased their intake of virgin olive oil, nuts, vegetables, legumes, and fruits ( P<0.05 for all within- and between-group differences). Participants in all three groups decreased their intake of meat and pastries, cakes, and sweets ( P<0.05 for all). Fiber, monounsaturated fatty acid, and polyunsaturated fatty acid intake increased in the Mediterranean diet groups ( P<0.005 for all). Favorable, although nonsignificant, changes in intake of other nutrients occurred only in the Mediterranean diet groups. Conclusions A 12-month behavioral intervention promoting the Mediterranean diet can favorably modify an individual's overall food pattern. The individual motivational interventions together with the group sessions and the free provision of high-fat and palatable key foods customary to the Mediterranean diet were effective in improving the dietary habits of participants in this trial.

Dietary virgin olive oil protects against lipid peroxidation and improves antioxidant status in the liver of rats chronically exposed to ethanol

Excessive ethanol intake induces severe tissue damage particularly in the liver through the generation of reactive oxygen species. The aim of this study was to determine the effect of a virgin olive oil-rich diet on oxidative stress induced by chronic ethanol exposure in rats. Wistar rats were treated daily with a 35% ethanol solution for 6 weeks and fed with a standard chow or a diet containing 5% virgin olive oil. By administering ethanol to rats, a severe toxicity occurred in their liver, as assessed by the significantly elevated levels of serum transaminases. The hepatic malondialdehyde level, indicator of lipid peroxidation, was also increased in ethanol-treated rats, whereas the hepatic antioxidant enzyme activities, namely, superoxide dismutase, glutathione peroxidase, and catalase were significantly reduced. The activity of glutathione reductase remained unchanged in rats. Fatty acid composition of the liver was also significantly changed with ethanol intake. In contrast, virgin olive oil intake during ethanol treatment in rats resulted in a higher antioxidant activity and inhibited toxicity to the liver, as monitored by the reduction of transaminases levels and hepatic lipid peroxidation. Rats showed a better profile of the antioxidant system with normal glutathione peroxidase activity and ameliorated superoxide dismutase and catalase activities. In conclusion, results of this study indicate that olive oil ingestion by rats protects the liver from ethanol-induced oxidative damage by affecting the cellular redox potential.

Changes in the phenolic content of low density lipoprotein after olive oil consumption in men. A randomized crossover controlled trial

Olive oil decreases the risk of CVD. This effect may be due to the fatty acid profile of the oil, but it may also be due to its antioxidant content which differs depending on the type of olive oil. In this study, the concentrations of oleic acid and antioxidants (phenolic compounds and vitamin E) in plasma and LDL were compared after consumption of three similar olive oils, but with differences in their phenolic content. Thirty healthy volunteers participated in a placebo-controlled, double-blind, crossover, randomized supplementation trial. Virgin, common, and refined olive oils were administered during three periods of 3 weeks separated by a 2-week washout period. Participants were requested to ingest a daily dose of 25 ml raw olive oil, distributed over the three meals of the day, during intervention periods. All three olive oils caused an increase in plasma and LDL oleic acid (P < 0.05) content. Olive oils rich in phenolic compounds led to an increase in phenolic compounds in LDL (P < 0.005). The concentration of phenolic compounds in LDL was directly correlated with the phenolic concentration in the olive oils. The increase in the phenolic content of LDL could account for the increase of the resistance of LDL to oxidation, and the decrease of the in vivo oxidized LDL, observed in the frame of this trial. Our results support the hypothesis that a daily intake of virgin olive oil promotes protective LDL changes ahead of its oxidation.

Olive oil and the haemostatic system

Interest in the Mediterranean diet (MD) has grown worldwide due to its link with greater longevity and lower cardiovascular disease rate, cancer and age cognitive decline. Despite the high complexity of its nutrients composition, olive oil emerges as its principal food, since it provides the higher percent of energy and a lot of bioactive compounds. In this review we will discuss the benefits of diets enriched in virgin olive oil, whose effects are probably due not only to its oleic acid content but also to its other potentially health-promoting components. Traditionally, the benefits of MD were linked to its effect on lipoprotein metabolism but today we realise that there exists a whole sheaf of other benefits, including the components of haemostasis: platelet function, thrombogenesis and fibrinolysis. A diet enriched in virgin olive oil can reduce the sensitivity of platelets to aggregation, decreasing von Willebrand and tromboxane B2 plasma levels. Moreover a particular interest has arisen about its capacity to decrease fasting Factor VII plasma levels and to avoid or modulate its postprandial activation. Also Tissue Factor expression in mononuclear cells could be reduced with the chronic intake of virgin olive oil and finally, studies performed in different experimental situation have shown that it could also increase fibrinolytic activity, reducing plasma concentration of Plasma Activator Inhibitor type-1.

Intake of phenol-rich virgin olive oil improves the postprandial prothrombotic profile in hypercholesterolemic patients

Background: Oxidative stress associated with postprandial lipemia contributes to endothelial dysfunction, which shifts hemostasis to a more thrombogenic state.Objective: We investigated whether a high concentration of phenols in olive oil can partly reverse this phenomenon.Design: Twenty-one hypercholesterolemic volunteers received 2 breakfasts rich in olive oils with different phenolic contents (80 or 400 ppm) according to a randomized, sequential crossover design. Plasma concentrations of lipid fractions, factor VII antigen (FVIIag), activated factor VII (FVIIa), and plasminogen activator inhibitor-1 (PAI-1) activity were measured at baseline and postprandially.Results: Concentrations of FVIIa increased less (P = 0.018) and plasma PAI-1 activity decreased more (P = 0.021) 2 h after the high-phenol meal than after the low-phenol meal. FVIIa concentrations 120 min after intake of the olive oil with a high phenol content correlated positively with fasting plasma triacylglycerols (P = 0.001), area under the curve (AUC) of triacylglycerols (P = 0.001), and AUC of nonesterified fatty acids (P = 0.024) and negatively with hydroxytyrosol plasma concentrations at 60 min (P = 0.039) and fasting HDL-cholesterol concentrations (P = 0.005). PAI-1 positively correlated with homeostasis model assessment of insulin resistance (P = 0.005) and fasting triacylglycerols (P = 0.025) and inversely with adiponectin (P = 0.026). In a multivariate analysis, the AUCs of nonesterified fatty acids (R2 = 0.467; β: 0.787; SE: 0.02; P < 0.001) and adiponectin (R2 = 0.232; β: −1.594; SE: 0.629; P < 0.05) were the strongest predictors of plasma FVIIa and PAI-1, respectively.Conclusions: A virgin olive oil with a high content of phenolic compounds changes the postprandial hemostatic profile to a less thrombogenic state.

Olive oil and haemostasis: a review on its healthy effects

Interest in the Mediterranean diet (MD) has grown worldwide. Despite the high complexity of its nutrients composition, olive oil emerges as its principal food, since it provides the higher percentage of energy and a lot of bioactive compounds. In this review, we will discuss the benefits of diets enriched in virgin olive oil, whose effects are probably due not only to its oleic acid content but also to its other potentially health-promoting components. Traditionally, the benefits of MD were linked to its effect on lipoprotein metabolism, but today we realise that there exists a whole sheaf of other benefits, including the components of haemostasis: platelet function, thrombogenesis and fibrinolysis. A diet enriched in virgin olive oil can reduce the sensitivity of platelets to aggregation, decreasing von Willebrand and thromboxane B2 plasma levels. Moreover, a particular interest has aroused about its capacity to decrease fasting factor VII plasma levels and to avoid or modulate its postprandial activation. In addition, tissue factor expression in mononuclear cells could be reduced with the chronic intake of virgin olive oil, and finally, studies performed in different experimental situation have shown that it could also increase fibrinolytic activity, reducing plasma concentration of plasma activator inhibitor type-1 (PAI-1). The MD is an alimentary model with a high content of monounsaturated fats that is capable of inducing a wide range of biological effects on the cardiovascular system. The application of modern focuses of study will dilucidate in the future the biological and clinical interest of these findings.

Olive Oil and Mitochondrial Oxidative Stress

This review summarizes studies on the role of olive oil intake in the prevention and attenuation of mitochondrial oxidative stress derived from several situations such as ageing, physical exercise, treatment with adriamycin or intake of thermally oxidised oils. After more than fifteen years of studies on these issues, results have demonstrated that under different models of oxidative stress the regular intake of virgin olive oil as dietary fat is able to attenuate or increase free radical production at the mitochondrial level to a lower extent than when n-6 polyunsaturated oils are used. In the same way, virgin olive oil leads to better function of the mitochondrial electron transport chain.

Constipation in the population over 50 years of age in Albacete province

To Determine the incidence of constipation in Albacete province and its relation with diet and lifestyle. Cross-sectional population survey. We studied 414 participants over 50 years of age in Albacete province. 445 persons over 50 years of age were included in the study. All participants were selected by systematic random sampling; 414 participants filled in the questionnaire correctly. age, weight and height, marital status, level of education and occupation; presence of a disease, number of sleep hours a day, physical exercise, smoking, alcohol intake, drug intake (anti-inflammatories and laxatives); bowel habit, diet, meal frequency and place; food intake frequency per week, daily intake of water, coffee, tea and herbal beverages; vitamin and fiber supplements; presence of cancer in the family. 56.9% of participants were women. Mean age 67.07 years. In Albacete province, 4.4% of the population over 50 years have a bowel habit consistent with constipation. Most participants had three meals a day (breakfast, lunch, and supper), while 50% had another meal in the morning or afternoon. These meals took place, habitually, in the domicile. There was a preponderance in daily intake of the following foods: milk (83.7%), bread (95.1%), vegetables (68.8%), fruit (91.8%), and virgin olive oil (96.6%). Fish was eaten every one to two days, and pulses and meat every three to six days. 44.4% of participants drank one to two liters of water a day. Only 3.9% of participants took some supplement; 35% of participants were on a diet. It was observed that 97.7% of participants with more than three defecations a week had a high intake of virgin olive oil; 65.7% of participants did some physical exercise customarily; 70.2% of participants were non-smokers, 10.2% were smokers, and 18.4% were ex-smokers. With regard to alcohol, the percentage of drinkers was 35.1%. The main class of medications taken by participants was NSAIDs - 14.5%; 79.7% took neither NSAIDs nor laxatives. Only 2.7% of participants took laxatives regularly. Most participants had relatively healthy eating habits.

Development of a Sensitive and Specific Solid Phase Extraction−Gas Chromatography−Tandem Mass Spectrometry Method for the Determination of Elenolic Acid, Hydroxytyrosol, and Tyrosol in Rat Urine

A novel gas chromatography-tandem mass spectrometry (GC-MS/MS) method was developed, using an ion trap mass spectrometer, for the simultaneous determination of olive oil bioactive components, elenolic acid, hydroxytyrosol, and tyrosol, in rat urine. Samples were analyzed by GC-MS/MS prior to and after enzymatic treatment. A solid phase extraction sample pretreatment step with greater than 80% analytical recoveries for all compounds was performed followed by a derivatization reaction prior to GC-MS/MS analysis. The calibration curves were linear for all compounds studied for a dynamic range between 1 and 500 ng. The limit of detection was in the mid picogram level for tyrosol and elenolic acid (300 pg) and in the low picogram level for hydroxytyrosol (2.5 pg). The method was applied to the analysis of rat urine samples after sustained oral intake of oleuropein or extra virgin olive oil as a diet supplement.

International conference on the healthy effect of virgin olive oil

1. Ageing represents a great concern in developed countries because the number of people involved and the pathologies related with it, like atherosclerosis, morbus Parkinson, Alzheimer's disease, vascular dementia, cognitive decline, diabetes and cancer. 2. Epidemiological studies suggest that a Mediterranean diet (which is rich in virgin olive oil) decreases the risk of cardiovascular disease. 3. The Mediterranean diet, rich in virgin olive oil, improves the major risk factors for cardiovascular disease, such as the lipoprotein profile, blood pressure, glucose metabolism and antithrombotic profile. Endothelial function, inflammation and oxidative stress are also positively modulated. Some of these effects are attributed to minor components of virgin olive oil. Therefore, the definition of the Mediterranean diet should include virgin olive oil. 4. Different observational studies conducted in humans have shown that the intake of monounsaturated fat may be protective against age-related cognitive decline and Alzheimer's disease. 5. Microconstituents from virgin olive oil are bioavailable in humans and have shown antioxidant properties and capacity to improve endothelial function. Furthermore they are also able to modify the haemostasis, showing antithrombotic properties. 6. In countries where the populations fulfilled a typical Mediterranean diet, such as Spain, Greece and Italy, where virgin olive oil is the principal source of fat, cancer incidence rates are lower than in northern European countries. 7. The protective effect of virgin olive oil can be most important in the first decades of life, which suggests that the dietetic benefit of virgin olive oil intake should be initiated before puberty, and maintained through life. 8. The more recent studies consistently support that the Mediterranean diet, based in virgin olive oil, is compatible with a healthier ageing and increased longevity. However, despite the significant advances of the recent years, the final proof about the specific mechanisms and contributing role of the different components of virgin olive oil to its beneficial effects requires further investigations.

Antioxidant effect of virgin olive oil in patients with stable coronary heart disease: a randomized, crossover, controlled, clinical trial

The Mediterranean diet, in which olive oil is the main source of fat, has been associated with a reduced incidence of coronary heart disease (CHD) and low blood pressure levels. Virgin olive oil (VOO), besides containing monounsaturated fat, is rich in phenolic compounds (PC) with antioxidant properties. The aim of this study was to examine the antioxidant and anti-hypertensive effect of two similar olive oils, but with differences in their PC (refined: 14.7 mg/kg versus virgin: 161.0 mg/kg), in 40 males with stable CHD. The study was a placebo controlled, crossover, randomized trial. A raw daily dose of 50 mL of VOO and refined olive oil (ROO) were sequentially administered over two periods of 3 weeks, preceded by 2-week washout periods in which ROO was used. Lower plasma oxidized LDL ( p < 0.001) and lipid peroxide levels ( p = 0.003), together with higher activities of glutathione peroxidase ( p = 0.033), were observed after VOO intervention. Systolic blood pressure decreased after intake of VOO ( p = 0.001) in hypertensive patients. No changes were observed in diastolic blood pressure, glucose, lipids, and antibodies against oxidized LDL. Consumption of VOO, rich in PC, could provide beneficial effects in CHD patients as an additional and complementary intervention to the pharmacological treatment.

Dietary fat type (virgin olive vs. sunflower oils) affects age-related changes in DNA double-strand-breaks, antioxidant capacity and blood lipids in rats

This study was designed to investigate the possible effect on DNA double-strand breaks, antioxidant capacity and blood lipids of feeding rats lifelong with two different dietary fat sources: virgin olive oil (rich in the monounsaturated oleic acid) or sunflower oil (rich in the polyunsaturated linoleic acid). No changes in mean or maximal lifespan were observed. Overall, aging led to increased levels of plasma cholesterol, triglycerides, phospholipids, total lipids, polyunsaturated fatty acids and DNA double-strand breaks. All these parameters were higher in animals fed on sunflower oil diet. Aging diminished total antioxidant capacity with both diets, but in a lower extension for virgin olive oil diet. A very good inverse correlation ( r=−0.715; P<0.01, for sunflower oil group and r=−0.535; P<0.01, for virgin olive oil group) between DNA damage and total antioxidant capacity was found. These results allow to conclude that dietary fat type should be considered in studies on aging, since the intake of oils with different polyunsaturation levels directly modulates total antioxidant capacity of plasma, DNA damage to peripheral blood lymphocytes and lead to important changes at the lipid metabolism level. In the present study best results were found after intake of virgin olive oil, which suggest the possible use of that edible oil to provide a healthier aging.

Hydroxytyrosol Excretion Differs between Rats and Humans and Depends on the Vehicle of Administration

Interest in the in vivo biological activities of olive oil phenolics is rapidly growing, and different models and vehicles of administration are used worldwide. Matters of practicality determine the use of rats rather than humans as the model of choice. Also, growing interest in nutraceuticals is leading to the formulation of compounds containing olive oil phenols. In this study, we compared metabolism and urinary excretion of hydroxytyrosol [(HT), the most representative phenol of olive oil] between rats and humans by evaluating excretion of HT and its major metabolite, homovanillyl alcohol. Also, we compared human excretion of HT when consumed as a natural component of extra virgin olive oil, when added to refined olive oil, or when added to yogurt (as an approximation of functional food). Urinary excretion of HT was greater in humans than in rats, a species with a high basal excretion of HT and its metabolites. The high (234% of HT administered) excretion of free HT suggests that hydrolysis of oleuropein administered in humans (still an unresolved issue) occurs in vivo. Moreover, human HT excretion was much higher after its administration as a natural component of olive oil (44.2% of HT administered) than after its addition to refined olive oil (23% of HT administered) or yogurt (5.8% of dose or approximately 13% of that recorded after virgin olive oil intake). These data suggest that the rat is not the appropriate model for the study of HT metabolism and that HT-containing functional foods should be carefully formulated.