Jaume Marrugat

The Effect of Polyphenols in Olive Oil on Heart Disease Risk Factors: A Randomized Trial

Context Olive oil, the main fat in the Mediterranean diet, contains polyphenols, which have antioxidant properties and may affect serum lipid levels. Contribution The authors studied virgin olive oil (high in polyphenols), refined olive oil (low in polyphenols), and a mixture of the 2 oils in equal parts. Two hundred healthy young men consumed 25 mL of an olive oil daily for 3 weeks followed by the other olive oils in a randomly assigned sequence. Olive oils with greater polyphenol content increased high-density lipoprotein (HDL) cholesterol levels and decreased serum markers of oxidation. Cautions The increase in HDL cholesterol level was small. Implications Virgin olive oil might have greater health benefits than refined olive oil. The Editors Polyphenol intake has been associated with low cancer and coronary heart disease (CHD) mortality rates (1). Antioxidant and anti-inflammatory properties and improvements in endothelial dysfunction and the lipid profile have been reported for dietary polyphenols (2). Studies have recently suggested that Mediterranean health benefits may be due to a synergistic combination of phytochemicals and fatty acids (3). Olive oil, rich in oleic acid (a monounsaturated fatty acid), is the main fat of the Mediterranean diet (4). To date, most of the protective effect of olive oil within the Mediterranean diet has been attributed to its high monounsaturated fatty acid content (5). However, if the effect of olive oil can be attributed solely to its monounsaturated fatty acid content, any type of olive oil, rapeseed or canola oil, or monounsaturated fatty acidenriched fat would provide similar health benefits. Whether the beneficial effects of olive oil on the cardiovascular system are exclusively due to oleic acid remains to be elucidated. The minor components, particularly the phenolic compounds, in olive oil may contribute to the health benefits derived from the Mediterranean diet. Among olive oils usually present on the market, virgin olive oils produced by direct-press or centrifugation methods have higher phenolic content (150 to 350 mg/kg of olive oil) (6). In experimental studies, phenolic compounds in olive oil showed strong antioxidant properties (7, 8). Oxidized low-density lipoprotein (LDL) is currently thought to be more damaging to the arterial wall than native LDL cholesterol (9). Results of randomized, crossover, controlled clinical trials on the antioxidant effect of polyphenols from real-life daily doses of olive oil in humans are, however, conflicting (10). Growing evidence suggests that dietary phenols (1115) and plant-based diets (16) can modulate lipid and lipoprotein metabolism. The Effect of Olive Oil on Oxidative Damage in European Populations (EUROLIVE) Study is a multicenter, randomized, crossover, clinical intervention trial that aims to assess the effect of sustained daily doses of olive oil, as a function of its phenolic content, on the oxidative damage to lipid and LDL cholesterol levels and the lipid profile as cardiovascular risk factors. Methods Participants We recruited healthy men, 20 to 60 years of age, from 6 European cities through newspaper and university advertisements. Of the 344 persons who agreed to be screened, 200 persons were eligible (32 men from Barcelona, Spain; 33 men from Copenhagen, Denmark; 30 men from Kuopio, Finland; 31 men from Bologna, Italy; 40 men from Postdam, Germany; and 34 men from Berlin, Germany) and were enrolled from September 2002 through June 2003 (Figure 1). Participants were eligible for study inclusion if they provided written informed consent, were willing to adhere to the protocol, and were in good health. We preselected volunteers when clinical record, physical examination, and blood pressure were strictly normal and the candidate was a nonsmoker. Next, we performed a complete blood count, biochemical laboratory analyses, and urinary dipstick tests to measure levels of serum glucose, total cholesterol, creatinine, alanine aminotransferase, and triglycerides. We included candidates with values within the reference range. Exclusion criteria were smoking; use of antioxidant supplements, aspirin, or drugs with established antioxidant properties; hyperlipidemia; obesity; diabetes; hypertension; intestinal disease; or any other disease or condition that would impair adherence. We excluded women to avoid the possible interference of estrogens, which are considered to be potential antioxidants (17). All participants provided written informed consent, and the local institutional ethics committees approved the protocol. Figure 1. Study flow diagram. Sequence of olive oil administration: 1) high-, medium-, and low-polyphenol olive oil; 2) medium-, low-, and high-polyphenol olive oil; and 3) low-, high-, and medium-polyphenol olive oil. Design and Study Procedure The trial was a randomized, crossover, controlled study. We randomly assigned participants consecutively to 1 of 3 sequences of olive oil administration. Participants received a daily dose of 25 mL (22 g) of 3 olive oils with high (366 mg/kg), medium (164 mg/kg), and low (2.7 mg/kg) polyphenol content (Figure 1) in replacement of other raw fats. Sequences were high-, medium-, and low-polyphenol olive oil (sequence 1); medium-, low-, and high-polyphenol olive oil (sequence 2); and low-, high-, and medium-polyphenol olive oil (sequence 3). In the coordinating center, we prepared random allocation to each sequence, taken from a Latin square, for each center by blocks of 42 participants (14 persons in each sequence), using specific software that was developed at the Municipal Institute for Medical Research, Barcelona, Spain (Aleator, Municipal Institute for Medical Research). The random allocation was faxed to the participating centers upon request for each individual included in the study. Treatment containers were assigned a code number that was concealed from participants and investigators, and the coordinating center disclosed the code number only after completion of statistical analyses. Olive oils were specially prepared for the trial. We selected a virgin olive oil with high natural phenolic content (366 mg/kg) and measured its fatty acid and vitamin E composition. We tested refined olive oil harvested from the same cultivar and soil to find an olive oil with similar quantities of fatty acid and a similar micronutrient profile. Vitamin E was adjusted to values similar to those of the selected virgin olive oil. Because phenolic compounds are lost in the refinement process, the refined olive oil had a low phenolic content (2.7 mg/kg). By mixing virgin and refined olive oil, we obtained an olive oil with an intermediate phenolic content (164 mg/kg). Olive oils did not differ in fat and micronutrient composition (that is, vitamin E, triterpenes, and sitosterols), with the exception of phenolic content. Three-week interventions were preceded by 2-week washout periods, in which we requested that participants avoid olive and olive oil consumption. We chose the 2-week washout period to reach the equilibrium in the plasma lipid profile because longer intervention periods with fat-rich diets did not modify the lipid concentrations (18). Daily doses of 25 mL of olive oil were blindly prepared in containers delivered to the participants at the beginning of each intervention period. We instructed participants to return the 21 containers at the end of each intervention period so that the daily amount of unconsumed olive oil could be registered. Dietary Adherence We measured tyrosol and hydroxytyrosol, the 2 major phenolic compounds in olive oil as simple forms or conjugates (7), by gas chromatography and mass spectrometry in 24-hour urine before and after each intervention period as biomarkers of adherence to the type of olive oil ingested. We asked participants to keep a 3-day dietary record at baseline and after each intervention period. We requested that participants in all centers avoid a high intake of foods that contain antioxidants (that is, vegetables, legumes, fruits, tea, coffee, chocolate, wine, and beer). A nutritionist also personally advised participants to replace all types of habitually consumed raw fats with the olive oils (for example, spread the assigned olive oil on bread instead of butter, put the assigned olive oil on boiled vegetables instead of margarine, and use the assigned olive oil on salads instead of other vegetable oils or standard salad dressings). Data Collection Main outcome measures were changes in biomarkers of oxidative damage to lipids. Secondary outcomes were changes in lipid levels and in biomarkers of the antioxidant status of the participants. We assessed outcome measures at the beginning of the study (baseline) and before (preintervention) and after (postintervention) each olive oil intervention period. We collected blood samples at fasting state together with 24-hour urine and recorded anthropometric variables. We measured blood pressure with a mercury sphygmomanometer after at least a 10-minute rest in the seated position. We recorded physical activity at baseline and at the end of the study and assessed it by using the Minnesota Leisure Time Physical Activity Questionnaire (19). We measured 1) glucose and lipid profile, including serum glucose, total cholesterol, high-density lipoprotein (HDL) cholesterol, and triglyceride levels determined by enzymatic methods (2023) and LDL cholesterol levels calculated by the Friedewald formula; 2) oxidative damage to lipids, including plasma-circulating oxidized LDL measured by enzyme immunoassay, plasma total F2-isoprostanes determined by using high-performance liquid chromatography and stable isotope-dilution and mass spectrometry, plasma C18 hydroxy fatty acids measured by gas chromatography and mass spectrometry, and serum LDL cholesterol uninduced conjugated dienes measured by spectrophotometry and adjusted for the cholesterol concentration in LDL cholesterol levels; 3) antioxidant sta

Estimación del riesgo coronario en España mediante la ecuación de Framingham calibrada

Rev Esp Cardiol 2003;56(3):253-61 253 Introducción y objetivos. Las ecuaciones de Framingham sobrestiman el riesgo de enfermedad coronaria en los países cuya incidencia es baja. En éstos, la ecuación debería adaptarse para la correcta prevención de la enfermedad coronaria. Se presentan las tablas de riesgo coronario global de Framingham calibradas para la población española. Pacientes y método. Se utilizó el procedimiento de calibración de la ecuación de Framingham, consistente en sustituir la prevalencia de factores de riesgo cardiovascular y la tasa de incidencia de acontecimientos coronarios de Framingham por las de nuestro medio. Se ha usado la ecuación de Framingham, que incluye el colesterol unido a lipoproteínas de alta densidad (cHDL). Se han calculado las probabilidades de acontecimiento a los 10 años y se han elaborado unas tablas con códigos de color y la probabilidad exacta en cada casilla correspondiente a las distintas combinaciones de los factores de riesgo clásicos, para una concentración de cHDL de 35-59 mg/dl. Resultados. Las tasas de acontecimientos coronarios y la prevalencia de factores de riesgo difieren considerablemente entre la población estudiada y Framingham. Valores de cHDL < 35 mg/dl incrementan el riesgo en un 50% y los > 60 mg/dl lo reducen en un 50%, aproximadamente. La proporción de casillas con una probabilidad de acontecimiento coronario a los 10 años superior al 9% es 2,3 veces menor, y la de casillas con una probabilidad > 19% es 13 veces menor en las tablas calibradas que en las originales de Framingham. Conclusiones. La función de Framingham calibrada puede constituir un instrumento para estimar con más precisión el riesgo coronario global en la prevención primaria de esta enfermedad en España. Su uso debe acompañarse de una validación apropiada y se debe trabajar en la elaboración de ecuaciones propias españolas.

Effect of a traditional Mediterranean diet on lipoprotein oxidation: a randomized controlled trial.

BACKGROUND Despite the richness in antioxidants of the Mediterranean diet, to our knowledge, no randomized controlled trials have assessed its effect on in vivo lipoprotein oxidation. METHODS A total of 372 subjects at high cardiovascular risk (210 women and 162 men; age range, 55-80 years), who were recruited into a large, multicenter, randomized, controlled, parallel-group clinical trial (the Prevención con Dieta Mediterránea [PREDIMED] Study) directed at testing the efficacy of the traditional Mediterranean diet (TMD) on the primary prevention of coronary heart disease, were assigned to a low-fat diet (n = 121) or one of 2 TMDs (TMD + virgin olive oil or TMD + nuts). The TMD participants received nutritional education and either free virgin olive oil for all the family (1 L/wk) or free nuts (30 g/d). Diets were ad libitum. Changes in oxidative stress markers were evaluated at 3 months. RESULTS After the 3-month interventions, mean (95% confidence intervals) oxidized low-density lipoprotein (LDL) levels decreased in the TMD + virgin olive oil (-10.6 U/L [-14.2 to -6.1]) and TMD + nuts (-7.3 U/L [-11.2 to -3.3]) groups, without changes in the low-fat diet group (-2.9 U/L [-7.3 to 1.5]). Change in oxidized LDL levels in the TMD + virgin olive oil group reached significance vs that of the low-fat group (P = .02). Malondialdehyde changes in mononuclear cells paralleled those of oxidized LDL. No changes in serum glutathione peroxidase activity were observed. CONCLUSIONS Individuals at high cardiovascular risk who improved their diet toward a TMD pattern showed significant reductions in cellular lipid levels and LDL oxidation. Results provide further evidence to recommend the TMD as a useful tool against risk factors for CHD. Trial Registration isrctn.org Identifier: ISRCTN35739639.

High prevalence of cardiovascular risk factors in Gerona, Spain, a province with low myocardial infarction incidence

STUDY OBJECTIVE: To establish the prevalence of main cardiovascular risk factors in the province of Gerona, where the incidence of myocardial infarction is known to be low. DESIGN: This was a cross sectional study of prevalence of cardiovascular risk factors conducted on a large random population sample. SETTING: The province of Gerona, Spain. PARTICIPANTS: Two thousand four hundred and four eligible inhabitants of Gerona aged between 25 and 74 years were randomly selected for a multi-stage sample stratified by age and sex. The following were standardly measured: lipids (total cholesterol, high density, low density, lipoprotein (a) and triglycerides), fibrinogen, basal glycaemia, arterial pressure, anthropometric variables, smoking, history of angina (Rose questionnaire), and a medical history questionnaire. Population measurements were standardised for the world population of 24 to 74 years of age. RESULTS: The participation rate was 72.7% (1748). Total mean cholesterol was 5.69 mmol/l in men and 5.61 mmol/l in women and mean high density cholesterol was 1.22 mmol/l and 1.47 mmol/l, respectively. Median lipoprotein (a) was 0.22 g/l. These three lipids increased significantly with age. Mean fibrinogen was 2.92 g/l in men and 3.09 g/l in women, and was higher in smokers. The prevalence of hypertension (systolic arterial tension > or = 140 mm Hg or diastolic > or = 90 mm Hg or drug treatment) was 31.3% in men and 27.7% in women. The proportion of male smokers was 33.8% and female smokers 22.7%. The proportion of female smokers in the 25-34 year age group exceeded that of the remaining age groups for both men and women. CONCLUSIONS: The prevalence of cardiovascular risk factors in Gerona is relatively high for the low myocardial infarction incidence typical of the area, although similar to that of other Spanish areas. The factors that confer sufficient protection to compensate for the effect of the prevalence of these risk factors remain to be elucidated.

An adaptation of the Framingham coronary heart disease risk function to European Mediterranean areas

Aim: To determine whether the Framingham function accurately predicts the 10 year risk of coronary disease and to adapt this predictive method to the characteristics of a Spanish population. Method and Results: A Framingham function for predicting 10 year coronary deaths and non-fatal myocardial infarction was applied to the population of the province of Gerona, Spain, where the cumulated incidence rate of myocardial infarction has been determined since 1988 by a specific registry. The prevalence of cardiovascular risk factors in this region of Spain was established in 1995 by a cross sectional study on a representative sample of 1748 people. The number of cases estimated by the Framingham function for 10 year coronary deaths and non-fatal myocardial infarction was compared with that observed. The Framingham function estimated 2425 coronary heart disease cases in women and 1181 were observed. In men, 9919 were estimated and 3706 were observed. Recalibrating the Framingham equations to the event rate and the prevalence of the risk factors in Gerona led to estimates very close to the number of cases observed in Gerona men and women. Conclusions: The Framingham function estimates more than doubled the actual risk of coronary disease observed in north east Spain. After calibration, the Framingham function became an effective method of estimating the risk in this region with low coronary heart disease incidence.

Epidemiología de la cardiopatía isquémica en España: estimación del número de casos y de las tendencias entre 1997 y 2005

Introduccion y objetivos En las dos ultimas decadas se ha acumulado una importante cantidad de informacion sobre la frecuencia de la cardiopatia isquemica en Espana, que se resume en este trabajo junto a una estimacion del numero absoluto de casos que habran aparecido en el ano 2002 y a la tendencia en el periodo 1997-2005. Metodos Se han revisado las publicaciones referidas a la situacion en la decada de los noventa en Espana. Se presentan las tasas y la estimacion del numero absoluto de pacientes con infarto agudo de miocardio (IAM) y los ingresados esperados por distintos sindromes coronarios agudos por comunidades autonomas en el ano 2002 y las tendencias entre 1997 y 2005. Resultados En el ano 2002 se habran producido unos 68.500 IAM, de los cuales 40.989 habran sido hospitalizados. El resto habra fallecido fuera de los hospitales. Ademas, el 24,9% de los ingresados tampoco habra sobrevivido 28 dias. Apenas la mitad de los pacientes tendra menos de 75 anos, edad con mejor pronostico (letalidad a los 28 dias del 38,8%). Se habran producido unos 33.500 ingresos por angina inestable, de los cuales el 4,5% habra fallecido a los 3 meses del ingreso. De mantenerse la incidencia estable, se ha estimado que el numero absoluto de casos de IAM aumentara un 2,28% anual en la poblacion (9.847 casos en total) y las hospitalizaciones por sindrome coronario agudo un 1,41% (8.817 casos en total) entre 1997 y 2005. Conclusion La cardiopatia isquemica genera una demanda asistencial creciente en Espana. Los pacientes con IAM tienen una gran letalidad a escala poblacional, ya que solo dos terceras partes de los aproximadamente 68.500 pacientes con esta patologia habran sido hospitalizados en el 2002.

Validity of an adaptation of the Framingham cardiovascular risk function: the VERIFICA study

Background: To assess the reliability and accuracy of the Framingham coronary heart disease (CHD) risk function adapted by the Registre Gironí del Cor (REGICOR) investigators in Spain. Methods: A 5-year follow-up study was completed in 5732 participants aged 35–74 years. The adaptation consisted of using in the function the average population risk factor prevalence and the cumulative incidence observed in Spain instead of those from Framingham in a Cox proportional hazards model. Reliability and accuracy in estimating the observed cumulative incidence were tested with the area under the curve comparison and goodness-of-fit test, respectively. Results: The Kaplan–Meier CHD cumulative incidence during the follow-up was 4.0% in men and 1.7% in women. The original Framingham function and the REGICOR adapted estimates were 10.4% and 4.8%, and 3.6% and 2.0%, respectively. The REGICOR-adapted function’s estimate did not differ from the observed cumulated incidence (goodness of fit in men, p = 0.078, in women, p = 0.256), whereas all the original Framingham function estimates differed significantly (p<0.001). Reliabilities of the original Framingham function and of the best Cox model fit with the study data were similar in men (area under the receiver operator characteristic curve 0.68 and 0.69, respectively, p = 0.273), whereas the best Cox model fitted better in women (0.73 and 0.81, respectively, p<0.001). Conclusion: The Framingham function adapted to local population characteristics accurately and reliably predicted the 5-year CHD risk for patients aged 35–74 years, in contrast with the original function, which consistently overestimated the actual risk.

Inactivating mutations in NPC1L1 and protection from coronary heart disease

BACKGROUND Ezetimibe lowers plasma levels of low-density lipoprotein (LDL) cholesterol by inhibiting the activity of the Niemann-Pick C1-like 1 (NPC1L1) protein. However, whether such inhibition reduces the risk of coronary heart disease is not known. Human mutations that inactivate a gene encoding a drug target can mimic the action of an inhibitory drug and thus can be used to infer potential effects of that drug. METHODS We sequenced the exons of NPC1L1 in 7364 patients with coronary heart disease and in 14,728 controls without such disease who were of European, African, or South Asian ancestry. We identified carriers of inactivating mutations (nonsense, splice-site, or frameshift mutations). In addition, we genotyped a specific inactivating mutation (p.Arg406X) in 22,590 patients with coronary heart disease and in 68,412 controls. We tested the association between the presence of an inactivating mutation and both plasma lipid levels and the risk of coronary heart disease. RESULTS With sequencing, we identified 15 distinct NPC1L1 inactivating mutations; approximately 1 in every 650 persons was a heterozygous carrier for 1 of these mutations. Heterozygous carriers of NPC1L1 inactivating mutations had a mean LDL cholesterol level that was 12 mg per deciliter (0.31 mmol per liter) lower than that in noncarriers (P=0.04). Carrier status was associated with a relative reduction of 53% in the risk of coronary heart disease (odds ratio for carriers, 0.47; 95% confidence interval, 0.25 to 0.87; P=0.008). In total, only 11 of 29,954 patients with coronary heart disease had an inactivating mutation (carrier frequency, 0.04%) in contrast to 71 of 83,140 controls (carrier frequency, 0.09%). CONCLUSIONS Naturally occurring mutations that disrupt NPC1L1 function were found to be associated with reduced plasma LDL cholesterol levels and a reduced risk of coronary heart disease. (Funded by the National Institutes of Health and others.).

Validation of the Minnesota leisure time physical activity questionnaire in Spanish women

PURPOSE Regular physical activity (PA) is associated with lower risk for several chronic diseases. It is important to validate PA measurement instruments in different populations. The objective was to validate the Minnesota leisure time PA questionnaire among Spanish women. METHODS A cross-sectional study with quota sampling was designed. Two PA groups (active, expending less than 301 MET-min x d(-1) in PA, and very active, expending more than 300 MET-min x d(-1)) and two age groups (18-40 and 41-60 yr) were defined. The Minnesota questionnaire was administered to obtain total energy expenditure in leisure time PA (EEPAtotal) and classified according to the intensity of the different types of PA (EEPAheavy, EEPAmoderate, and EEPAlight). The 250 women recruited performed an exercise test to assess fitness. RESULTS Spearman correlation coefficients among EEPAtotal, EEPAheavy, EEPAmoderate, EEPAlight, and fitness were 0.39, 0.51, 0.13, and 0.02, respectively. Multiple linear regression model adjusted by the different EEPAs and age accounted for 46% of fitness variability. Besides age, only EEPAmoderate and EEPAheavy were associated with fitness. CONCLUSION The Spanish version of the Minnesota questionnaire is a valid instrument for measuring leisure time PA performed in the last year in Spanish women aged 18-60 yr. Moderate and heavy physical activity are adequately assessed whereas light physical activity practice assessment may be questionable.

Response of oxidative stress biomarkers to a 16-week aerobic physical activity program, and to acute physical activity, in healthy young men and women.

Physical activity (PA) is associated with a reduced risk of coronary heart disease, and may favorably modify the antioxidant-prooxidant balance. This study assessed the effects of aerobic PA training on antioxidant enzyme activity, oxidized LDL concentration, and LDL resistance to oxidation, as well as the effect of acute PA on antioxidant enzyme activity before and after the training period. Seventeen sedentary healthy young men and women were recruited for 16 weeks of training. The activity of superoxide dismutase in erythrocytes (E-SOD), glutathione peroxidase in whole blood (GSH-Px), and glutathione reductase in plasma (P-GR), and the oxidized LDL concentration and LDL composition, diameter, and resistance to oxidation were determined before and after training. Shortly before and after this training period they also performed a bout of aerobic PA for 30 min. The antioxidant enzyme activity was also determined at 0 min, 30 min, 60 min, 120 min, and 24 h after both bouts of PA. Training induces an increase in GSH-Px (27.7%), P-GR (17.6%), and LDL resistance to oxidation, and a decrease in oxidized LDL (-15.9%). After the bout of PA, an increase in E-SOD and GSH-Px was observed at 0 min, with a posterior decrease in enzyme activity until 30-60 min, and a tendency to recover the basal values at 120 min and 24 h. Training did not modify this global response pattern. Regular PA increases endogenous antioxidant activity and LDL resistance to oxidation, and decreases oxidized LDL concentration; 30 min of aerobic PA decreases P-GR and B-GSH-Px activity in the first 30-60 min with a posterior recovery.