Primary Prevention of Cardiovascular Disease with a Mediterranean Diet Supplemented with Extra-Virgin Olive Oil or Nuts.

BACKGROUND: Observational cohort studies and a secondary prevention trial have shown inverse associations between adherence to the Mediterranean diet and cardiovascular risk. METHODS: In a multicenter trial in Spain, we assigned 7447 participants (55 to 80 years of age, 57% women) who were at high cardiovascular risk, but with no cardiovascular disease at enrollment, to one of three diets: a Mediterranean diet supplemented with extra-virgin olive oil, a Mediterranean diet supplemented with mixed nuts, or a control diet (advice to reduce dietary fat). Participants received quarterly educational sessions and, depending on group assignment, free provision of extra-virgin olive oil, mixed nuts, or small nonfood gifts. The primary end point was a major cardiovascular event (myocardial infarction, stroke, or death from cardiovascular causes). After a median follow-up of 4.8 years, the trial was stopped on the basis of a prespecified interim analysis. In 2013, we reported the results for the primary end point in the Journal. We subsequently identified protocol deviations, including enrollment of household members without randomization, assignment to a study group without randomization of some participants at 1 of 11 study sites, and apparent inconsistent use of randomization tables at another site. We have withdrawn our previously published report and now report revised effect estimates based on analyses that do not rely exclusively on the assumption that all the participants were randomly assigned. RESULTS: A primary end-point event occurred in 288 participants; there were 96 events in the group assigned to a Mediterranean diet with extra-virgin olive oil (3.8%), 83 in the group assigned to a Mediterranean diet with nuts (3.4%), and 109 in the control group (4.4%). In the intention-to-treat analysis including all the participants and adjusting for baseline characteristics and propensity scores, the hazard ratio was 0.69 (95% confidence interval [CI], 0.53 to 0.91) for a Mediterranean diet with extra-virgin olive oil and 0.72 (95% CI, 0.54 to 0.95) for a Mediterranean diet with nuts, as compared with the control diet. Results were similar after the omission of 1588 participants whose study-group assignments were known or suspected to have departed from the protocol. CONCLUSIONS: In this study involving persons at high cardiovascular risk, the incidence of major cardiovascular events was lower among those assigned to a Mediterranean diet supplemented with extra-virgin olive oil or nuts than among those assigned to a reduced-fat diet. (Funded by Instituto de Salud Carlos III, Spanish Ministry of Health, and others; Current Controlled Trials number, ISRCTN35739639 .).

Effect of olive oil phenolic compounds on the expression of blood pressure-related genes in healthy individuals.

PURPOSE: To investigate whether the ingestion of olive oil having different phenolic contents influences the expression of blood pressure-related genes, involved in the renin-angiotensin-aldosterone system, in healthy humans. METHODS: A randomized, double-blind, crossover human trial with 18 healthy subjects, who ingested 25 mL/day of olive oils (1) high (366 mg/kg, HPC) and (2) low (2.7 mg/kg, LPC) in phenolic compounds for 3 weeks, preceded by 2-week washout periods. Determination of selected blood pressure-related gene expression in peripheral blood mononuclear cells (PBMNC) by qPCR, blood pressure and systemic biomarkers. RESULTS: HPC decreased systolic blood pressure compared to pre-intervention values and to LPC, and maintained diastolic blood pressure values compared to LPC. HPC decreased ACE and NR1H2 gene expressions compared with pre-intervention values, and IL8RA gene expression compared with LPC. CONCLUSIONS: The introduction to the diet of an extra-virgin olive oil rich in phenolic compounds modulates the expression of some of the genes related to the renin-angiotensin-aldosterone system. These changes could underlie the decrease in systolic blood pressure observed.

Primary prevention of cardiovascular disease with a Mediterranean diet.

BACKGROUND: Observational cohort studies and a secondary prevention trial have shown an inverse association between adherence to the Mediterranean diet and cardiovascular risk. We conducted a randomized trial of this diet pattern for the primary prevention of cardiovascular events. METHODS: In a multicenter trial in Spain, we randomly assigned participants who were at high cardiovascular risk, but with no cardiovascular disease at enrollment, to one of three diets: a Mediterranean diet supplemented with extra-virgin olive oil, a Mediterranean diet supplemented with mixed nuts, or a control diet (advice to reduce dietary fat). Participants received quarterly individual and group educational sessions and, depending on group assignment, free provision of extra-virgin olive oil, mixed nuts, or small nonfood gifts. The primary end point was the rate of major cardiovascular events (myocardial infarction, stroke, or death from cardiovascular causes). On the basis of the results of an interim analysis, the trial was stopped after a median follow-up of 4.8 years. RESULTS: A total of 7447 persons were enrolled (age range, 55 to 80 years); 57% were women. The two Mediterranean-diet groups had good adherence to the intervention, according to self-reported intake and biomarker analyses. A primary end-point event occurred in 288 participants. The multivariable-adjusted hazard ratios were 0.70 (95% confidence interval [CI], 0.54 to 0.92) and 0.72 (95% CI, 0.54 to 0.96) for the group assigned to a Mediterranean diet with extra-virgin olive oil (96 events) and the group assigned to a Mediterranean diet with nuts (83 events), respectively, versus the control group (109 events). No diet-related adverse effects were reported. CONCLUSIONS: Among persons at high cardiovascular risk, a Mediterranean diet supplemented with extra-virgin olive oil or nuts reduced the incidence of major cardiovascular events. (Funded by the Spanish government's Instituto de Salud Carlos III and others; Controlled-Trials.com number, ISRCTN35739639.).

The NUTRAOLEOUM Study, a randomized controlled trial, for achieving nutritional added value for olive oils.

BACKGROUND: Virgin olive oil, a recognized healthy food, cannot be consumed in great quantities. We aim to assess in humans whether an optimized virgin olive oil with high phenolic content (OVOO, 429 mg/Kg) and a functional one (FOO), both rich in phenolic compounds (429 mg/Kg) and triterpenic acids (389 mg/kg), could provide health benefits additional to those supplied a by a standard virgin olive oil (VOO). METHODS/DESIGN: A randomized, double-blind, crossover, controlled study will be conducted. Healthy volunteers (aged 20 to 50) will be randomized into one of three groups of daily raw olive oil consumption: VOO, OVOO, and FOO (30 mL/d). Olive oils will be administered over 3-week periods preceded by 2-week washout ones. The main outcomes will be markers of lipid and DNA oxidation, inflammation, and vascular damage. A bioavailability and dose-response study will be nested within this sustained- consumption one. It will be made up of 18 volunteers and be performed at two stages after a single dose of each olive oil. Endothelial function and nitric oxide will be assessed at baseline and at 4 h and 6 h after olive oil single dose ingestion. DISCUSSION: For the first time the NUTRAOLEUM Study will provide first level evidence on the health benefits in vivo in humans of olive oil triterpenes (oleanolic and maslinic acid) in addition to their bioavailability and disposition. TRIAL REGISTRATION: The Trial has been registered in ClinicalTrials.gov ID: NCT02520739 .

Alkylglycerols reduce serum complement and plasma vascular endothelial growth factor in obese individuals.

Alkylglycerols (AKGs), isolated or present in shark liver oil have anti-inflammatory properties. Complement 3 (C3) and 4 (C4) participate in lipid metabolism and in obesity, contributing to the metabolic syndrome and to the low-grade inflammation associated with obesity. In a randomized, controlled, crossover study, 26 non-diabetes obese individuals were assigned two preparations with low (LAC, 10 mg AKGs) and high (HAC, 20 mg AKGs) AKG content. Intervention periods were of 3 weeks preceded by 2-week washout periods in which shark liver oil was avoided. Cholesterol, C3, C4, and vascular endothelial growth factor (VEGF) decreased in a linear trend (P < 0.01) from baseline (control) to LAC and HAC. Values after HAC were significantly lower (P < 0.05) versus both baseline and after LAC. No adverse effects were observed or reported. Data from this pilot study open a promising field for the study of the beneficial effects of AKGs on cardiovascular risk factors in obese individuals.

Olive Oil Polyphenols Decrease LDL Concentrations and LDL Atherogenicity in Men in a Randomized Controlled Trial.

BACKGROUND: Olive oil polyphenols have shown protective effects on cardiovascular risk factors. Their consumption decreased oxidative stress biomarkers and improved some features of the lipid profile. However, their effects on LDL concentrations in plasma and LDL atherogenicity have not yet been elucidated. OBJECTIVE: Our objective was to assess whether the consumption of olive oil polyphenols could decrease LDL concentrations [measured as apolipoprotein B-100 (apo B-100) concentrations and the total number of LDL particles] and atherogenicity (the number of small LDL particles and LDL oxidizability) in humans. METHODS: The study was a randomized, cross-over controlled trial in 25 healthy European men, aged 20-59 y, in the context of the EUROLIVE (Effect of Olive Oil Consumption on Oxidative Damage in European Populations) study. Volunteers ingested 25 mL/d raw low-polyphenol-content olive oil (LPCOO; 366 mg/kg) or high-polyphenol-content olive oil (HPCOO; 2.7 mg/kg) for 3 wk. Interventions were preceded by 2-wk washout periods. Effects of olive oil polyphenols on plasma LDL concentrations and atherogenicity were determined in the sample of 25 men. Effects on lipoprotein lipase (LPL) gene expression were assessed in another sample of 18 men from the EUROLIVE study. RESULTS: Plasma apo B-100 concentrations and the number of total and small LDL particles decreased (mean ± SD: by 5.94% ± 16.6%, 11.9% ± 12.0%, and 15.3% ± 35.1%, respectively) from baseline after the HPCOO intervention. These changes differed significantly from those after the LPCOO intervention, which resulted in significant increases of 6.39% ± 16.6%, 4.73% ± 22.0%, and 13.6% ± 36.4% from baseline (P < 0.03). LDL oxidation lag time increased by 5.0% ± 10.3% from baseline after the HPCOO intervention, which was significantly different only relative to preintervention values (P = 0.038). LPL gene expression tended to increase by 26% from baseline after the HPCOO intervention (P = 0.08) and did not change after the LPCOO intervention. CONCLUSION: The consumption of olive oil polyphenols decreased plasma LDL concentrations and LDL atherogenicity in healthy young men. This trial was registered at www.controlled-trials.com as ISRCTN09220811.

Olive oil polyphenols enhance high-density lipoprotein function in humans: a randomized controlled trial.

OBJECTIVE: Olive oil polyphenols have shown beneficial properties against cardiovascular risk factors. Their consumption has been associated with higher cholesterol content in high-density lipoproteins (HDL). However, data on polyphenol effects on HDL quality are scarce. We, therefore, assessed whether polyphenol-rich olive oil consumption could enhance the HDL main function, its cholesterol efflux capacity, and some of its quality-related properties, such HDL polyphenol content, size, and composition. APPROACH AND RESULTS: A randomized, crossover, controlled trial with 47 healthy European male volunteers was performed. Participants ingested 25 mL/d of polyphenol-poor (2.7 mg/kg) or polyphenol-rich (366 mg/kg) raw olive oil in 3-week intervention periods, preceded by 2-week washout periods. HDL cholesterol efflux capacity significantly improved after polyphenol-rich intervention versus the polyphenol-poor one (+3.05% and -2.34%, respectively; P=0.042). Incorporation of olive oil polyphenol biological metabolites to HDL, as well as large HDL (HDL2) levels, was higher after the polyphenol-rich olive oil intervention, compared with the polyphenol-poor one. Small HDL (HDL3) levels decreased, the HDL core became triglyceride-poor, and HDL fluidity increased after the polyphenol-rich intervention. CONCLUSIONS: Olive oil polyphenols promote the main HDL antiatherogenic function, its cholesterol efflux capacity. These polyphenols increased HDL size, promoted a greater HDL stability reflected as a triglyceride-poor core, and enhanced the HDL oxidative status, through an increase in the olive oil polyphenol metabolites content in the lipoprotein. Our results provide for the first time a first-level evidence of an enhancement in HDL function by polyphenol-rich olive oil.

Virgin olive oil: a key food for cardiovascular risk protection.

Olive oil is considered to be one of the most healthy dietary fats. However, several types of olive oils are present in the market. A key question for the consumer is: What of the olive oils is the best when concerning nutritional purposes? With the data available at present, the answer is: the Virgin Olive Oil (VOO), rich in phenolic compounds. On November 2011, the European Food Safety Authority released a claim concerning the benefits of daily ingestion of olive oil rich in phenolic compounds, such as VOO. In this review, we summarised the key work that has provided the evidence of the benefits of VOO consumption on other types of edible oils, even olive oils. We focused on data from randomised, controlled human studies, which are capable of providing the evidence of Level I that is required for performing nutritional recommendations at population level.

Prevention of diabetes with Mediterranean diets: a subgroup analysis of a randomized trial.

BACKGROUND: Interventions promoting weight loss can reduce the incidence of type 2 diabetes mellitus. Whether dietary changes without calorie restriction also protect from diabetes has not been evaluated. OBJECTIVE: To assess the efficacy of Mediterranean diets for the primary prevention of diabetes in the Prevención con Dieta Mediterránea trial, from October 2003 to December 2010 (median follow-up, 4.1 years). DESIGN: Subgroup analysis of a multicenter, randomized trial. (Current Controlled Trials: ISRCTN35739639) SETTING: Primary care centers in Spain. PARTICIPANTS: Men and women without diabetes (3541 patients aged 55 to 80 years) at high cardiovascular risk. INTERVENTION: Participants were randomly assigned and stratified by site, sex, and age but not diabetes status to receive 1 of 3 diets: Mediterranean diet supplemented with extra-virgin olive oil (EVOO), Mediterranean diet supplemented with nuts, or a control diet (advice on a low-fat diet). No intervention to increase physical activity or lose weight was included. MEASUREMENTS: Incidence of new-onset type 2 diabetes mellitus (prespecified secondary outcome). RESULTS: During follow-up, 80, 92, and 101 new-onset cases of diabetes occurred in the Mediterranean diet supplemented with EVOO, Mediterranean diet supplemented with mixed nuts, and control diet groups, respectively, corresponding to rates of 16.0, 18.7, and 23.6 cases per 1000 person-years. Multivariate-adjusted hazard ratios were 0.60 (95% CI, 0.43 to 0.85) for the Mediterranean diet supplemented with EVOO and 0.82 (CI, 0.61 to 1.10) for the Mediterranean diet supplemented with nuts compared with the control diet. LIMITATIONS: Randomization was not stratified by diabetes status. Withdrawals were greater in the control group. CONCLUSION: A Mediterranean diet enriched with EVOO but without energy restrictions reduced diabetes risk among persons with high cardiovascular risk. PRIMARY FUNDING SOURCE: Instituto de Salud Carlos III.