Itziar Zazpe

Relative validity of a semi-quantitative food-frequency questionnaire in an elderly Mediterranean population of Spain

The aim of the present study was to assess reproducibility and relative validity of a self-administered FFQ used in the PREDIMED Study, a clinical trial for primary prevention of CVD by Mediterranean diet in a population at high cardiovascular risk. The FFQ was administered twice (FFQ1 and FFQ2) to explore reproducibility at 1 year. Four 3 d dietary records (DR) were used as reference to explore validity; participants therefore recorded their food intake over 12 d in the course of 1 year. The degree of misclassification in the FFQ was also evaluated by a contingency table of quintiles comparing the information from the FFQ2 and the DR. A total of 158 men and women (aged 55-80 years) were asked not to modify their dietary habits during the study period. Reproducibility for food groups, energy and nutrient intake, explored by the Pearson correlation coefficient (r) ranged 0.50-0.82, and the intraclass correlation coefficient (ICC) ranged from 0.63 to 0.90. The FFQ2 tended to report higher energy and nutrient intake than the DR. The validity indices of the FFQ in relation to the DR for food groups and energy and nutrient intake ranged (r) from 0.24 to 0.72, while the range of the ICC was between 0.40 and 0.84. With regard to food groups, 68-83 % of individuals were in the same or adjacent quintile in both methods, a figure which decreased to 55-75 % for energy and nutrient intake. We concluded that FFQ measurements had good reproducibility and a relative validity similar to those of FFQ used in other prospective studies.

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.

Adherence to a Mediterranean-type diet and reduced prevalence of clustered cardiovascular risk factors in a cohort of 3204 high-risk patients

Background The Mediterranean food pattern (MeDiet) has been suggested to have beneficial effects on cardiovascular risk factors. Scarcity of assessment of this effect on large samples of patients at high risk is, however, observed. Our objective was to estimate the association between adherence to MeDiet and the prevalence of risk factors in 3204 asymptomatic high-risk patients. Design Cross-sectional assessment of baseline characteristics of participants in a primary prevention trial. Methods Participants were assessed by their usual primary-care physicians to ascertain the prevalence of diet-related cardiovascular risk factors (diabetes, hypertension, dyslipidemia, or obesity) using standard diagnostic criteria. A dietitian interviewed each participant to obtain a 14-point score measuring the degree of adherence to MeDiet. Results Adherence to MeDiet was inversely associated with individual risk factors and, above all, with the clustering of them. The multivariate adjusted odds ratio to present simultaneously the four risk factors for those above the median value of the MeDiet score was 0.67 (95% confidence interval: 0.53–0.85). The multivariate odds ratios for successive categories of adherence to MeDiet were 1 (ref.), 1.03, 0.85, 0.70 and 0.54 (P for trend ≤0.001). Conclusion Following a MeDiet was inversely associated with the clustering of hypertension, diabetes, obesity, and hypercholesterolemia among high-risk patients.

Dietary inflammatory index and anthropometric measures of obesity in a population sample at high cardiovascular risk from the PREDIMED (PREvención con DIeta MEDiterránea) trial.

The dietary inflammatory index (DII) is a new tool to assess the inflammatory potential of the diet. In the present study, we aimed to determine the association between the DII and BMI, waist circumference and waist:height ratio (WHtR). We conducted a cross-sectional study of 7236 participants recruited into the PREvención con DIeta MEDiterránea trial. Information from a validated 137-item FFQ was used to calculate energy, food and nutrient intakes. A fourteen-item dietary screener was used to assess adherence to the Mediterranean diet (MeDiet). Sex-specific multivariable linear regression models were fitted to estimate differences (and 95 % CI) in BMI, waist circumference and WHtR across the quintiles of the DII. All nutrient intakes, healthy foods and adherence to the MeDiet were higher in the quintile with the lowest DII score (more anti-inflammatory values) except for intakes of animal protein, saturated fat and monounsaturated fat. Although an inverse association between the DII and total energy was apparent, the DII was associated with higher average BMI, waist circumference and WHtR after adjusting for known risk factors. The adjusted difference in the WHtR for women and men between the highest and lowest quintiles of the DII was 1·60 % (95 % CI 0·87, 2·33) and 1·04 % (95 % CI 0·35, 1·74), respectively. Pro-inflammatory scores remained associated with obesity after controlling for the effect that adherence to a MeDiet had on inflammation. In conclusion, the present study shows a direct association between the DII and indices of obesity, and supports the hypothesis that diet may have a role in the development of obesity through inflammatory modulation mechanisms.

Evidence of the Gluten-Free and Casein-Free Diet in Autism Spectrum Disorders: A Systematic Review

In autism spectrum disorders, many parents resort to alternative treatments and these are generally perceived as risk free. Among these, the most commonly used is the gluten-free, casein-free diet. The objective of this work was to conduct a systematic review of studies published from 1970 to date related to the gluten-free, casein-free diet in autism spectrum disorder patients. Few studies can be regarded as providing sound scientific evidence since they were blinded randomized controlled trials, and even these were based on small sample sizes, reducing their validity. We observed that the evidence on this topic is currently limited and weak. We recommend that it should be only used after the diagnosis of an intolerance or allergy to foods containing the allergens excluded in gluten-free, casein-free diets. Future research should be based on this type of design, but with larger sample sizes.

Prospective study of changes in sugar-sweetened beverage consumption and the incidence of the metabolic syndrome and its components: the SUN cohort.

The incidence of the metabolic syndrome (MetS) is increasing and lifestyle behaviours may play a role. The aim of the present study was to prospectively assess the association between changes in the consumption of sugar-sweetened beverages (SSB) and the incidence of the MetS and its components in a Spanish cohort of university graduates. We included 8157 participants initially free of the MetS and followed up during at least 6 years. SSB consumption was collected by a FFQ previously validated in Spain. The change in SSB consumption was calculated as the difference between SSB consumption at a 6-year follow-up and baseline consumption. The MetS was defined according to the International Diabetes Federation and the American Heart Association/National Heart, Lung, and Blood Institutes new definition of the MetS that had harmonised previous definitions. The associations between changes in SSB intake and the MetS were examined using multiple logistic regression. We observed 361 incident cases of the MetS. Participants who increased their consumption of SSB (upper v. lower quintile) had a significantly higher risk of developing the MetS (adjusted OR 2·2, 95 % CI 1·4, 3·5; P for trend = 0·003). Similarly, they presented a significantly higher risk of developing high blood pressure (adjusted OR 1·6, 95 % CI 1·3, 2·1), central obesity (adjusted OR 2·3, 95 % CI 1·9, 2·7), hypertriacylglycerolaemia (adjusted OR 1·7, 95 % CI 1·1, 2·6) or impaired fasting glucose (adjusted OR 1·6, 95 % CI 1·1, 2·2). In conclusion, an increase in SSB consumption was associated with a higher risk of developing the MetS and other metabolic disorders after 6 years of follow-up in a Mediterranean cohort of university graduates.

Dietary Patterns and Total Mortality in a Mediterranean Cohort: The SUN Project

BACKGROUND Different dietary patterns have been associated with several health outcomes, including morbidity and mortality. There is little evidence on the association between empirically derived dietary patterns and all-cause mortality in Southern European populations. OBJECTIVE The aim of our study was to prospectively evaluate the association between an empirically derived dietary pattern and all-cause mortality. DESIGN The Seguimiento Universidad de Navarra (SUN) Project is an ongoing, multipurpose, prospective and dynamic Spanish cohort. PARTICIPANTS/SETTING Participants were a prospective cohort of 16,008 middle-aged Spanish adults. All of them were university graduates (alumni) (59.6% women, mean age 38 years). Usual diet was assessed at baseline with a validated semiquantitative food frequency questionnaire. MAIN OUTCOME MEASURES Deaths were confirmed by review of medical records and of the National Death Index. STATISTICAL ANALYSIS Dietary patterns were ascertained through a factor (principal component) analysis based on 30 predefined food groups. Participants were classified according to tertiles of adherence to the three main dietary patterns identified with factor analysis. Cox regression models were fitted to estimate multivariable-adjusted hazard ratios and 95% CIs for mortality. RESULTS Three major dietary patterns were identified. They were labelled Western dietary pattern (rich in red and processed meat, potatoes, and fast food), Mediterranean dietary pattern (rich in vegetables, fish and seafood, fruits, and olive oil), and alcoholic beverages dietary pattern. During follow-up, 148 deaths were reported (mean age at death 54.5 years). After adjustment for potential confounders, the lowest risk of all-cause mortality was found in the tertile of highest adherence to the Mediterranean dietary pattern (adjusted hazard ratio for third vs first tertile 0.53, 95% CI 0.34 to 0.84) (P for trend <0.01). The Western dietary pattern and alcoholic beverages dietary pattern showed no significant association with mortality. CONCLUSIONS Greater adherence to an empirically derived dietary pattern approaching the traditional Mediterranean diet was associated with a reduction in the risk of all-cause mortality among middle-aged Mediterranean adults.

Fiber intake and all-cause mortality in the Prevención con Dieta Mediterránea (PREDIMED) study

BACKGROUND Few observational studies have examined the effect of dietary fiber intake and fruit and vegetable consumption on total mortality and have reported inconsistent results. All of the studies have been conducted in the general population and typically used only a single assessment of diet. OBJECTIVE We investigated the association of fiber intake and whole-grain, fruit, and vegetable consumption with all-cause mortality in a Mediterranean cohort of elderly adults at high cardiovascular disease (CVD) risk by using repeated measurements of dietary information and taking into account the effect of a dietary intervention. DESIGN We followed up 7216 men (55-75 y old) and women (60-75 y old) at high CVD risk in the Prevención con Dieta Mediterránea (PREDIMED) trial for a mean of 5.9 y. Data were analyzed as an observational cohort. Participants were initially free of CVD. A 137-item validated food-frequency questionnaire administered by dietitians was repeated annually to assess dietary exposures (fiber, fruit, vegetable, and whole-grain intakes). Deaths were identified through the continuing medical care of participants and the National Death Index. An independent, blinded Event Adjudication Committee adjudicated causes of death. Cox regression models were used to estimate HRs of death during follow-up according to baseline dietary exposures and their yearly updated changes. RESULTS In up to 8.7 y of follow-up, 425 participants died. Baseline fiber intake and fruit consumption were significantly associated with lower risk of death [HRs for the fifth compared with the first quintile: 0.63 (95% CI: 0.46, 0.86; P = 0.015) and 0.59 (95% CI: 0.42, 0.82; P = 0.004), respectively]. When the updated dietary information was considered, participants with fruit consumption >210 g/d had 41% lower risk of all-cause mortality (HR: 0.59; 95% CI: 0.44, 0.78). Associations were strongest for CVD mortality than other causes of death. CONCLUSION Fiber and fruit intakes are associated with a reduction in total mortality. PREDIMED was registered at controlled-trials.com as ISRCTN35739639.

Food Selectivity in Autism Spectrum Disorders A Systematic Review

Autism spectrum disorders are characterized by difficulties with reciprocal social interactions and restricted patterns of behavior and interest; one of these characteristic behaviors is food selectivity. The objective of this study was to perform a systematic review of the literature published between 1970 and 2013 concerning this eating behavior. The articles identified were analyzed in terms of sample size, study design, and criteria for assessment and intervention, as well as the results, level of evidence and grade of recommendation. The main search was conducted in Medline, Cochrane Library, Scielo, ScienceDirect, and Embase). There is empirical evidence and an overall scientific consensus supporting an association between food selectivity and autism spectrum disorders.

Egg consumption and risk of cardiovascular disease in the SUN Project

Background/Objectives:Egg consumption has been associated with the risk of cardiovascular diseases (CVDs), but evidence is scarce and inconsistent. Our aim was to examine the association between egg consumption and incidence of CVD in a prospective dynamic Mediterranean cohort of 14 185 university graduates.Subjects/Methods:Egg intake was assessed using a 136-item-validated food-frequency questionnaire. Baseline consumption was categorized into no consumption or <1 egg/week, 1 egg/week, 2–4 eggs/week and >4 eggs/week. The presence of cardiovascular risk factors was assessed by questionnaire at baseline, and the incidence of CVD was assessed using biennial assessments. The median follow-up was 6.1 years. Cox regression models were fitted to estimate multivariable-adjusted hazard ratios (HRs) for CVD (myocardial infarction, revascularization procedures or stroke). Outcomes were confirmed by review of medical records.Results:During a median follow-up of 6.1 years, 91 new confirmed cases of CVD were observed. No association was found between egg consumption and the incidence of CVD (HR: 1.10, 95% confidence interval: 0.46–2.63) for the highest versus the lowest category of egg consumption after adjusting for age, sex, total energy intake, adherence to the Mediterranean food pattern and other cardiovascular risk factors. Results were robust to different analytical scenarios.Conclusions:No association between egg consumption and the incidence of CVD was found in this Mediterranean cohort.