Helmut Schröder

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.

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.

Association of fast food consumption with energy intake, diet quality, body mass index and the risk of obesity in a representative Mediterranean population

The aim of the present study was to describe the association of fast food consumption with BMI, energy intake and diet quality in a Mediterranean population. The subjects were Spanish men (n 1491) and women (n 1563) aged 25-74 years who were examined in 1999-2000, in a population-based cross-sectional survey in northeast Spain (Girona). Dietary intake was assessed using a FFQ that included four typical fast food items. Two dietary-quality indices, the Mediterranean diet score and the healthy eating index, were created. Height and weight were measured. Within the population studied, 10.1 % reported eating fast food at least once per month. Dietary energy intake and energy density were directly associated with frequency of fast food consumption. Multivariate logistic regression analysis adjusted for lifestyle and educational level showed an inverse association of frequency of fast food consumption with meeting the dietary reference intake (DRI) for energy (P = 0.001). The consumption of fast food more than once per week increased the risk of overall low diet quality (P < 0.001). BMI was directly associated with fast food consumption expressed in g/d (P = 0.025) and in kJ/d (P = 0.017). The risk of being obese increased with the frequency of fast food consumption (P = 0.046). Fast food consumption was associated with higher energy intakes, poor diet quality and higher BMI. The likelihood of not meeting the DRI for energy, and of being obese, increased with the frequency of fast food consumption.

Alternative Methods of Accounting for Underreporting and Overreporting When Measuring Dietary Intake-Obesity Relations

Misreporting characterized by the reporting of implausible energy intakes may undermine the valid estimation of diet-disease relations, but the methods to best identify and account for misreporting are unknown. The present study compared how alternate approaches affected associations between selected dietary factors and body mass index (BMI) by using data from the European Prospective Investigation Into Cancer and Nutrition-Spain. A total of 24,332 women and 15,061 men 29-65 years of age recruited from 1992 to 1996 for whom measured height and weight and validated diet history data were available were included. Misreporters were identified on the basis of disparities between reported energy intakes and estimated requirements calculated using the original Goldberg method and 2 alternatives: one that substituted basal metabolic rate equations that are more valid at higher BMIs and another that used doubly labeled water-predicted total energy expenditure equations. Compared with results obtained using the original method, underreporting was considerably lower and overreporting higher with alternative methods, which were highly concordant. Accounting for misreporters with all methods yielded diet-BMI relations that were more consistent with expectations; alternative methods often strengthened associations. For example, among women, multivariable-adjusted differences in BMI for the highest versus lowest vegetable intake tertile (β = 0.37 (standard error, 0.07)) were neutral after adjusting with the original method (β = 0.01 (standard error, 07)) and negative using the predicted total energy expenditure method with stringent cutoffs (β = -0.15 (standard error, 0.07)). Alternative methods may yield more valid associations between diet and obesity-related outcomes.

Anti-inflammatory effect of virgin olive oil in stable coronary disease patients: a randomized, crossover, controlled trial

Objectives:To assess the effect of two similar olive oils, but with differences in their phenolic compounds (powerful antioxidant compounds), on inflammatory markers in stable coronary heart disease patients.Design:Placebo-controlled, crossover, randomized trial.Setting:Cardiology Department of Hospital del Mar and Institut Municipal d’Investigació Mèdica (Barcelona).Subjects:Twenty-eight stable coronary heart disease patients.Interventions:A raw daily dose of 50 ml of virgin and refined olive oil (ROO) was sequentially administered over two periods of 3-weeks, preceded by 2-week washout periods in which ROO was used.Results:Interleukin-6 (P<0.002) and C-reactive protein (P=0.024) decreased after virgin olive oil intervention. No changes were observed in soluble intercellular and vascular adhesion molecules, glucose and lipid profile.Conclusions:Consumption of virgin olive oil, could provide beneficial effects in stable coronary heart disease patients as an additional intervention to the pharmacological treatment.

Mediterranean Diet and Invasive Breast Cancer Risk Among Women at High Cardiovascular Risk in the PREDIMED Trial: A Randomized Clinical Trial

IMPORTANCE Breast cancer is the leading cause of female cancer burden, and its incidence has increased by more than 20% worldwide since 2008. Some observational studies have suggested that the Mediterranean diet may reduce the risk of breast cancer. OBJECTIVE To evaluate the effect of 2 interventions with Mediterranean diet vs the advice to follow a low-fat diet (control) on breast cancer incidence. DESIGN, SETTING, AND PARTICIPANTS The PREDIMED study is a 1:1:1 randomized, single-blind, controlled field trial conducted at primary health care centers in Spain. From 2003 to 2009, 4282 women aged 60 to 80 years and at high cardiovascular disease risk were recruited after invitation by their primary care physicians. INTERVENTIONS Participants were randomly allocated to 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). MAIN OUTCOMES AND MEASURES Breast cancer incidence was a prespecified secondary outcome of the trial for women without a prior history of breast cancer (n = 4152). RESULTS After a median follow-up of 4.8 years, we identified 35 confirmed incident cases of breast cancer. Observed rates (per 1000 person-years) were 1.1 for the Mediterranean diet with extra-virgin olive oil group, 1.8 for the Mediterranean diet with nuts group, and 2.9 for the control group. The multivariable-adjusted hazard ratios vs the control group were 0.32 (95% CI, 0.13-0.79) for the Mediterranean diet with extra-virgin olive oil group and 0.59 (95% CI, 0.26-1.35) for the Mediterranean diet with nuts group. In analyses with yearly cumulative updated dietary exposures, the hazard ratio for each additional 5% of calories from extra-virgin olive oil was 0.72 (95% CI, 0.57-0.90). CONCLUSIONS AND RELEVANCE This is the first randomized trial finding an effect of a long-term dietary intervention on breast cancer incidence. Our results suggest a beneficial effect of a Mediterranean diet supplemented with extra-virgin olive oil in the primary prevention of breast cancer. These results come from a secondary analysis of a previous trial and are based on few incident cases and, therefore, need to be confirmed in longer-term and larger studies. TRIAL REGISTRATION ISRCTN.org Identifier: ISRCTN35739639.

Adherence to the Mediterranean diet is associated with better mental and physical health

The aim of the present study was to analyse the association between adherence to the Mediterranean diet and self-perceived mental and physical health function, controlled for confounding effects of age, smoking, BMI, alcohol consumption, educational level, leisure-time physical activity and the presence of chronic conditions. A random sample of the 35-74-year-old population (3910 men and 4285 women) of Gerona, Spain, was examined in 2000 and 2005 in two independent population-based cross-sectional surveys. Dietary intake was assessed using a validated FFQ. The Mediterranean diet score (MDS) was calculated according to tertile distribution of energy-adjusted food consumption considered characteristic for the Mediterranean region. Health-related quality of life was measured using the SF-12 questionnaire. Alcohol consumption, leisure-time physical activity and smoking habits were recorded. Weight and height were measured. Age-adjusted linear regression analysis revealed a significant (P < 0.01) direct association of the MDS with self-reported mental and physical health in both sexes. An increase of 5 units of the MDS was directly associated with changes of 0.74 and 1.15 units in men and women, respectively, in the mental component score after controlling for potential confounders. The age-adjusted direct association of the MDS with self-reported scoring of physical health remained stable after adjusting for several confounders in men but was attenuated in women. Adherence to the Mediterranean diet was associated with higher scoring for self-perceived health.

Low-fat dairy products and blood pressure : follow-up of 2290 older persons at high cardiovascular risk participating in the PREDIMED study

High blood pressure (BP) has been ranked as the most important risk factor worldwide regarding attributable deaths. Dietary habits are major determinants of BP. Among them, frequent intake of low-fat dairy products may protect against hypertension. Our aim was to assess the relationship between low-fat dairy product intake and BP levels and their changes after 12-month follow-up in a cohort of asymptomatic older persons at high cardiovascular risk recruited into a large-scale trial assessing the effects of Mediterranean diets on cardiovascular outcomes. Data from 2290 participants, including 1845 with hypertension, were available for analyses. Dairy products were not a specific part of the intervention; thus, data were analysed as an observational cohort. Dietary information was collected with validated semi-quantitative FFQ and trained personnel measured BP. To assess BP changes, we undertook cross-sectional analyses at baseline and at the end of follow-up and longitudinal analyses. A statistically significant inverse association between low-fat dairy product intake and systolic BP was observed for the 12-month longitudinal analysis. In the longitudinal analysis, the adjusted systolic and diastolic BP were significantly lower in the highest quintile of low-fat dairy product intake (-4.2 (95% CI -6.9, -1.4) and -1.8 (95% CI -3.2, -0.4) mmHg respectively), whereas the point estimates for the difference in diastolic BP indicated a modest non-significant inverse association. Intake of low-fat dairy products was inversely associated with BP in an older population at high cardiovascular risk, suggesting a possible protective effect against hypertension.

Dietary Inflammatory Index and Incidence of Cardiovascular Disease in the PREDIMED Study

Previous studies have reported an association between a more pro-inflammatory diet profile and various chronic metabolic diseases. The Dietary Inflammatory Index (DII) was used to assess the inflammatory potential of nutrients and foods in the context of a dietary pattern. We prospectively examined the association between the DII and the incidence of cardiovascular disease (CVD: myocardial infarction, stroke or cardiovascular death) in the PREDIMED (Prevención con Dieta Mediterránea) study including 7216 high-risk participants. The DII was computed based on a validated 137-item food frequency questionnaire. Multivariate-adjusted hazard ratios (HR) and 95% confidence intervals of CVD risk were computed across quartiles of the DII where the lowest (most anti-inflammatory) quartile is the referent. Risk increased across the quartiles (i.e., with increasing inflammatory potential): HRquartile2 = 1.42 (95%CI = 0.97–2.09); HRquartile3 = 1.85 (1.27–2.71); and HRquartile4 = 1.73 (1.15–2.60). When fit as continuous the multiple-adjusted hazard ratio for each additional standard deviation of the DII was 1.22 (1.06–1.40). Our results provide direct prospective evidence that a pro-inflammatory diet is associated with a higher risk of cardiovascular clinical events.