Valentina Ruiz-Gutiérrez

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 governments Instituto de Salud Carlos III and others; Controlled-Trials.com number, ISRCTN35739639.).

Reduction in the Incidence of Type 2-Diabetes with the Mediterranean Diet: Results of the PREDIMED-Reus Nutrition Intervention Randomized Trial

OBJECTIVE To test the effects of two Mediterranean diet (MedDiet) interventions versus a low-fat diet on incidence of diabetes. RESEARCH DESIGN AND METHODS This was a three-arm randomized trial in 418 nondiabetic subjects aged 55–80 years recruited in one center (PREDIMED-Reus, northeastern Spain) of the Prevención con Dieta Mediterránea [PREDIMED] study, a large nutrition intervention trial for primary cardiovascular prevention in individuals at high cardiovascular risk. Participants were randomly assigned to education on a low-fat diet (control group) or to one of two MedDiets, supplemented with either free virgin olive oil (1 liter/week) or nuts (30 g/day). Diets were ad libitum, and no advice on physical activity was given. The main outcome was diabetes incidence diagnosed by the 2009 American Diabetes Association criteria. RESULTS After a median follow-up of 4.0 years, diabetes incidence was 10.1% (95% CI 5.1–15.1), 11.0% (5.9–16.1), and 17.9% (11.4–24.4) in the MedDiet with olive oil group, the MedDiet with nuts group, and the control group, respectively. Multivariable adjusted hazard ratios of diabetes were 0.49 (0.25–0.97) and 0.48 (0.24–0.96) in the MedDiet supplemented with olive oil and nuts groups, respectively, compared with the control group. When the two MedDiet groups were pooled and compared with the control group, diabetes incidence was reduced by 52% (27–86). In all study arms, increased adherence to the MedDiet was inversely associated with diabetes incidence. Diabetes risk reduction occurred in the absence of significant changes in body weight or physical activity. CONCLUSIONS MedDiets without calorie restriction seem to be effective in the prevention of diabetes in subjects at high cardiovascular risk.

A Short Screener Is Valid for Assessing Mediterranean Diet Adherence among Older Spanish Men and Women

Ensuring the accuracy of dietary assessment instruments is paramount for interpreting diet-disease relationships. The present study assessed the relative and construct validity of the 14-point Mediterranean Diet Adherence Screener (MEDAS) used in the Prevención con Dieta Mediterránea (PREDIMED) study, a primary prevention nutrition-intervention trial. A validated FFQ and the MEDAS were administered to 7146 participants of the PREDIMED study. The MEDAS-derived PREDIMED score correlated significantly with the corresponding FFQ PREDIMED score (r = 0.52; intraclass correlation coefficient = 0.51) and in the anticipated directions with the dietary intakes reported on the FFQ. Using Bland Altmans analysis, the average MEDAS Mediterranean diet score estimate was 105% of the FFQ PREDIMED score estimate. Limits of agreement ranged between 57 and 153%. Multiple linear regression analyses revealed that a higher PREDIMED score related directly (P < 0.001) to HDL-cholesterol (HDL-C) and inversely (P < 0.038) to BMI, waist circumference, TG, the TG:HDL-C ratio, fasting glucose, and the cholesterol:HDL-C ratio. The 10-y estimated coronary artery disease risk decreased as the PREDIMED score increased (P < 0.001). The MEDAS is a valid instrument for rapid estimation of adherence to the Mediterranean diet and may be useful in clinical practice.

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.

Cohort Profile: Design and methods of the PREDIMED study

The Spanish Ministry of Health—Instituto de Salud Carlos III (ISCIII) funded the project for the period 2003–05 (RTIC G03/140). In 2006 a new funding modality was established by ISCIII through the CIBER (Centros de Investigacion Biomedica En Red). Fisiopatologia de la Obesidad y Nutricion (CIBERobn), which is providing funding for 7 of the original research groups, whereas the other 12 were funded by a new research network (RTIC RD 06/0045). Other official funds from Spanish government agencies have been obtained for subprojects related to intermediate outcomes (lipoproteins, inflammatory markers, vascular imaging, genomic and proteomic studies, etc.). Obviously, the donation by food companies of all the VOO and mixed nuts needed throughout the duration of the study is a substantial contribution.

Prevention of Diabetes With Mediterranean Diets: A Subgroup Analysis of a Randomized Trial

Context Can changes in diet prevent diabetes in older adults? Contribution This subgroup analysis of a multicenter trial involved older adults with high risk for heart disease who were randomly assigned to a Mediterranean diet supplemented with either extra-virgin olive oil or mixed nuts or to a low-fat control diet. Neither energy restriction nor increased physical activity was advised. After 4 years of follow-up, fewer persons in the Mediterranean diet groups developed diabetes than in the control group. Implication Changes in dietary patterns that do not necessarily lead to weight loss or include energy restrictions could help prevent diabetes in some older adults. The Editors Type 2 diabetes mellitus represents a major health problem because worldwide prevalence has more than doubled in the past 3 decades, with nearly 347 million persons with diabetes in 2010 (1), and is a potent risk factor for cardiovascular disease (CVD), blindness, renal failure, and lower limb amputation (2). Compelling evidence shows that diabetes can be prevented with lifestyle changes. Intensive lifestyle modification promoting weight loss through energy-restricted diets together with increased physical activity can decrease incident diabetes to as low as 50% (3). Indeed, lifestyle modification has performed better than pharmacologic approaches (such as metformin or rosiglitazone) in diabetes prevention (46). Of interest, the benefit of lifestyle changes in decreasing diabetes risk seems to extend beyond the termination of active intervention (68). However, there is little information on whether changes in the overall dietary pattern, without energy restriction, increased physical activity, and ensuing weight loss, may also be effective to prevent diabetes. Prospective epidemiologic studies strongly suggest that dietary patterns characterized by high consumption of fruit, vegetables, whole grains, and fish and reduced consumption of red and processed meat, sugar-sweetened beverages, and starchy foods delay diabetes onset (9). In the last 6 years, the traditional Mediterranean diet has emerged as a healthy dietary pattern that is also associated with a decreased risk for diabetes (1012). The Mediterranean diet is moderately rich in fat (35% to 40% of energy), especially from vegetable sources (rich in olive oil and nuts), and relatively low in dairy products. Moderate consumption of alcohol, mostly wine, and frequent use of sauces with tomato, onions, garlic, and spices for meal preparation are also typical. Preliminary data from the PREDIMED (Prevencin con Dieta Mediterrnea) study (1317) showed that traditional Mediterranean diets enriched with high-fat foods of vegetable origin decreased the incidence of diabetes (18). However, that report studied participants only from 1 of the 11 PREDIMED recruiting centers. In this analysis, we provide the final results on diabetes incidence in the whole multicenter trial after a median follow-up of 4.1 years. Methods Design Overview The PREDIMED study is a parallel-group, randomized, primary cardiovascular prevention trial done in Spain in persons at high risk but without CVD at baseline. The protocol, design, objectives, and methods have been reported in detail elsewhere (13, 14). Briefly, participants were randomly assigned in a 1:1:1 ratio to 1 of 3 nutrition interventions: Mediterranean diet supplemented with extra-virgin olive oil (EVOO), Mediterranean diet supplemented with mixed nuts, or a control diet consisting of advice to reduce intake of all types of fat. A complete list of PREDIMED study investigators is available in Supplement 1. The local institutional review boards approved the protocol at each study location, and all participants provided written informed consent. Supplement. Original Version (PDF) Supplement 1. List of Prevencin con Dieta Mediterrnea Study Investigators Setting and Participants Eligible participants were community-dwelling men (aged 55 to 80 years) and women (aged 60 to 80 years) without CVD at baseline who had either type 2 diabetes or at least 3 or more cardiovascular risk factors, namely current smoking, hypertension, hypercholesterolemia, low high-density lipoprotein cholesterol levels, overweight or obesity, and family history of premature CVD. Exclusion criteria have previously been reported (13). Randomization and Intervention From October 2003 to June 2009, 7447 suitable candidates were enrolled in the trial. The study nurse from each recruiting center randomly assigned each participant to the corresponding intervention group following computer-generated random numbers for allocation contained in sealed envelopes, which were centrally prepared for each center by the coordinating unit. Four strata of randomization were built by sex and age (cutoff, 70 years) but not by baseline diabetes status. The primary care physicians did not participate in the randomization process. The study nurses were independent of the nursing staff of the primary care health centers. Therefore, they were not involved in the usual clinical care of participants, and their exclusive role was to collect data for the trial. Given the nature of the interventions (nutritional advice and provision of foods), only investigators assessing outcomes were blinded with respect to intervention assignment. This was done by providing them with coded data sets and medical records blinded with respect to the personal identity of the participant and without any information on treatment allocation. Because our main objective was to determine the effect of the 3 interventions on diabetes incidence, this report includes data only on participants who did not have diabetes at baseline and for whom we could ascertain the incidence of diabetes during follow-up (n= 3541) (Figure 1). Figure 1. Study flow diagram. EVOO = extra-virgin olive oil; MedDiet = Mediterranean diet. A behavioral intervention promoting the Mediterranean diet was implemented in the corresponding groups of the trial, as described (13). Dietitians gave personalized advice to participants about the amount and use of EVOO for cooking and dressing; weekly intake of nuts; increased consumption of vegetables, fruits, legumes, and fish; recommended intake of white meat instead of red or processed meat; avoidance of butter, fast food, sweets, pastries, or sugar-sweetened beverages; and the dressing of dishes with sofrito sauce (using tomato, garlic, onion, and spices simmered in olive oil). Reduction of alcoholic beverages other than wine was advised to all participants. Wine with meals was recommended with moderation only to habitual drinkers. At baseline and quarterly thereafter, dietitians conducted individual and group dietary training sessions to provide information on typical Mediterranean foods, seasonal shopping lists, meal plans, and recipes for each group. In each session, a 14-item questionnaire was used to assess adherence to the Mediterranean diet (13, 14) so that personalized advice could be provided to upgrade participants adherence. The same questionnaire was assessed yearly in the control group. Participants assigned to the 2 Mediterranean diet groups received allotments of either EVOO (50 mL/d) or mixed nuts (30 g/d: 15 g of walnuts, 7.5 g of almonds, and 7.5 g of hazelnuts) at no cost. Participants assigned to the control diet received recommendations to reduce intake of all types of fat (from both animal and vegetable sources) and received nonfood gifts (kitchenware, tableware, aprons, or shopping bags). Through October 2006, participants in the control group received only a leaflet describing the low-fat diet. Thereafter, participants assigned to the control diet also received personalized advice and were invited to group sessions with the same frequency and intensity as those in the Mediterranean diet groups. A separate 9-item dietary questionnaire (14) was used to assess adherence to the low-fat diet. Neither energy restriction nor increased physical activity was advised for any intervention group. At baseline examination and yearly during follow-up, we administered a 137-item validated semiquantitative food-frequency questionnaire (19); the validated Spanish version of the Minnesota Leisure-time Physical Activity Questionnaire (20); and a 47-item questionnaire about education, lifestyle, medical history, and medication use. At baseline, trained personnel performed electrocardiography and anthropometric and blood pressure measurements. Blood pressure was measured in triplicate by using a validated semiautomatic oscillometer with a 5-minute interval between measurements and the participant in a sitting position (Omron HEM-705CP, Omron, Hoofddorp, the Netherlands). Fasting blood and spot urine were sampled at baseline and follow-up years 1, 3, 5, and 7. After an overnight fast, tubes for EDTA plasma, citrate plasma, and serum and urine samples were collected and aliquots were coded and stored at 80C in the central laboratory until analysis. Serum glucose, cholesterol, and triglyceride levels were measured using standard enzymatic methods. High-density lipoprotein cholesterol was measured after precipitation with phosphotungstic acid and magnesium chloride. Biomarkers of adherence to the supplemental foods, including urine hydroxytyrosol levels and plasma -linolenic acid proportions, which are reliable biomarkers of EVOO and walnut intake, respectively, were measured in random subsamples of participants during the first 5 years of follow-up (by gas chromatographymass spectrometry and by gas chromatography, respectively). Laboratory technicians were blinded to intervention group. Outcomes and Follow-up Diabetes was a prespecified secondary outcome of the PREDIMED trial. IT was considered to be present at baseline by clinical diagnosis or use of antidiabetic medication. New-onset diabetes during follow-up was diagnosed using the American Diabetes Association criteria, namely fasting plasma glucose levels of 7.0 mmol/L or g

In vivo nutrigenomic effects of virgin olive oil polyphenols within the frame of the Mediterranean diet: a randomized controlled trial

The aim of the study was to assess whether benefits associated with the traditional Mediterranean diet (TMD) and virgin olive oil (VOO) consumption could be mediated through changes in the expression of atherosclerosis‐related genes. A randomized, parallel, controlled clinical trial in healthy volunteers (n=90) aged 20 to 50 yr was performed. Threemonth intervention groups were as follows: 1) TMD with VOO (TMD+VOO), 2) TMD with washed virgin olive oil (TMD+WOO), and 3) control with participants’ habitual diet. WOO was similar to VOO, but with a lower polyphenol content (55 vs. 328 mg/kg, respectively). TMD consumption decreased plasma oxidative and inflammatory status and the gene expression related with both inflammation [INF‐γ (INFy), Rho GTPase‐activating protein15 (ARHGAP15), and interleukin‐7 receptor (IL7R)] and oxidative stress [adrenergic ß2‐receptor (ADRB2) and polymerase (DNA‐directed) κ (POLK)] in peripheral blood mononuclear cells. All effects, with the exception of the decrease in POLK expression, were particularly observed when VOO, rich in polyphenols, was present in the TMD dietary pattern. Our results indicate a significant role of olive oil polyphenols in the down‐regulation of proatherogenic genes in the context of a TMD. In addition, the benefits associated with a TMD and olive oil polyphenol consumption on cardiovascular risk can be mediated through nutrigenomic effects.—Konstantinidou, V., Covas, M.‐I., Mun˜oz‐Aguayo, D., Khymenets, O., de la Torre, R., Saez, G., del Carmen Tormos, M., Toledo, E., Marti, A., Ruiz‐Gutiérrez, V., Ruiz Mendez, M. V., Fito, M. In vivo nutrigenomic effects of virgin olive oil polyphenols within the frame of the Mediterranean diet: a randomized controlled trial. FASEBJ. 24, 2546–2557 (2010). www.fasebj.org

A 14-Item Mediterranean Diet Assessment Tool and Obesity Indexes among High-Risk Subjects: The PREDIMED Trial

Objective Independently of total caloric intake, a better quality of the diet (for example, conformity to the Mediterranean diet) is associated with lower obesity risk. It is unclear whether a brief dietary assessment tool, instead of full-length comprehensive methods, can also capture this association. In addition to reduced costs, a brief tool has the interesting advantage of allowing immediate feedback to participants in interventional studies. Another relevant question is which individual items of such a brief tool are responsible for this association. We examined these associations using a 14-item tool of adherence to the Mediterranean diet as exposure and body mass index, waist circumference and waist-to-height ratio (WHtR) as outcomes. Design Cross-sectional assessment of all participants in the “PREvención con DIeta MEDiterránea” (PREDIMED) trial. Subjects 7,447 participants (55–80 years, 57% women) free of cardiovascular disease, but with either type 2 diabetes or ≥3 cardiovascular risk factors. Trained dietitians used both a validated 14-item questionnaire and a full-length validated 137-item food frequency questionnaire to assess dietary habits. Trained nurses measured weight, height and waist circumference. Results Strong inverse linear associations between the 14-item tool and all adiposity indexes were found. For a two-point increment in the 14-item score, the multivariable-adjusted differences in WHtR were −0.0066 (95% confidence interval, –0.0088 to −0.0049) for women and –0.0059 (–0.0079 to –0.0038) for men. The multivariable-adjusted odds ratio for a WHtR>0.6 in participants scoring ≥10 points versus ≤7 points was 0.68 (0.57 to 0.80) for women and 0.66 (0.54 to 0.80) for men. High consumption of nuts and low consumption of sweetened/carbonated beverages presented the strongest inverse associations with abdominal obesity. Conclusions A brief 14-item tool was able to capture a strong monotonic inverse association between adherence to a good quality dietary pattern (Mediterranean diet) and obesity indexes in a population of adults at high cardiovascular risk.

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 > 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 individuals 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.

Effects of virgin olive oil phenolics on scavenging of reactive nitrogen species and upon nitrergic neurotransmission.

The major phenolics from the polar fraction of virgin olive oil (caffeic acid, oleuropein, tyrosol and hydroxytyrosol) have well-established antioxidant activities but their effects on reactive nitrogen species and nitrergic neurotransmission have not been fully investigated. The three catechol compounds were active as scavengers of nitric oxide generated spontaneously from the decomposition of sodium nitroprusside (approximately 50% inhibition achieved at 75 microM), and had similar ability to scavenge chemically generated peroxynitrite, as determined by an alpha1-antiproteinase inactivation assay (67.2%-92.4% reduction when added at 1 mM). Tyrosol was less active in these tests, but does not possess the catechol functionality. Despite their ability to interact with chemically prepared nitric oxide, neither oleuropein nor hydroxytyrosol at 5 microM altered NO*-mediated relaxations of the nerve-stimulated rat anococcygeus preparation, but this may be because the nitrergic transmitter is protected from the effects of externally applied scavengers. In conclusion, the phenolics found in virgin olive oil possess ability to scavenge reactive oxygen and nitrogen species that are implicated in human pathologies, but their impact may be restricted to those species present in the extracellular environment.