M. A. Martínez-González

A systematic review of socio-economic differences in food habits in Europe: consumption of fruit and vegetables

Objective: To evaluate the differences in the consumption of fruit and vegetables between groups with different socio-economic status (SES) in the adult population of European countries.Design: A systematic review of published and unpublished surveys of food habits conducted between 1985 and 1999 in 15 European countries. Educational level and occupational status were used as indicators of SES. A pooled estimate of the mean difference between the highest and the lowest level of education and occupation was calculated separately for men and women, using DerSimonian and Lairds random effects model.Setting: The inclusion criteria of studies were: use of a validated method for assessing intake at the individual level; selection of a nationwide sample or a representative sample of a region; and providing the mean and standard deviation of overall fruit and vegetable consumption for each level of education or occupation, and separately for men and women.Subjects: Participants in the individual surveys had to be adults (18–85 y).Results: Eleven studies from seven countries met the criteria for being included in the meta-analysis. A higher SES was associated with a greater consumption of both fruit and vegetables. The pooled estimate of the difference in the intake of fruit was 24.3 g/person/day (95% confidence interval (CI) 14.0–34.7) between men in the highest level of education and those in the lowest level of education. Similarly, this difference was 33.6 g/person/day for women (95% CI 22.5–44.8). The differences regarding vegetables were 17.0 g/person/day (95% CI 8.6–25.5) for men and 13.4 g/person/day (95% CI 7.1–19.7) for women. The results were in the same direction when occupation instead of education was used as an indicator of SES.Conclusions: Although we cannot exclude over-reporting of intake by those with highest SES, it is unlikely that this potential bias could fully explain the differences we have found. Our results suggest that an unhealthier nutrition pattern may exist among adults belonging to lower socio-economic levels in Europe.Sponsorship: The present study was supported by the European Unions FAIR programme (FAIR-97-3096).European Journal of Clinical Nutrition (2000) 54, 706–714

The role of diet in the prevention of type 2 diabetes

Type 2 diabetes mellitus is an important preventable disease and a growing public health problem. Epidemiologic and interventional studies suggest that weight loss is the main driving force to reduce diabetes risk. Landmark clinical trials of lifestyle changes in subjects with prediabetes have shown that diet and exercise leading to weight loss consistently reduce the incidence of diabetes. However, from these studies it cannot be established whether dietary changes alone play a significant role in preventing diabetes. Here we review epidemiologic and clinical trial evidence relating nutrients, foods and dietary patterns to diabetes risk and the possible mechanisms involved. The differential effects of carbohydrate and fat quantity and quality, and those of specific foods and whole diets are discussed. Importantly, most dietary components influencing diabetes risk have similar effects on biomarkers of cardiovascular risk and inflammation. The conclusion is that there is no universal dietary strategy to prevent diabetes or delay its onset. Together with the maintenance of ideal body weight, the promotion of the so-called prudent diet (characterized by a higher intake of food groups that are generally recommended for health promotion, particularly plant-based foods, and a lower intake of red meat, meat products, sweets, high-fat dairy and refined grains) or a Mediterranean dietary pattern rich in olive oil, fruits and vegetables, including whole grains, pulses and nuts, low-fat dairy, and moderate alcohol consumption (mainly red wine) appears as the best strategy to decrease diabetes risk, especially if dietary recommendations take into account individual preferences, thus enabling long-time adherence.

Components of the mediterranean-type food pattern and serum inflammatory markers among patients at high risk for cardiovascular disease

Objective:To evaluate associations between components of the Mediterranean diet and circulating markers of inflammation in a large cohort of asymptomatic subjects at high risk for cardiovascular disease.Subjects/Methods:A total of 339 men and 433 women aged between 55 and 80 years at high cardiovascular risk because of presence of diabetes or at least three classical cardiovascular risk factors, food consumption was determined by a semi-quantitative food frequency questionnaire. Serum concentrations of high-sensitivity C-reactive protein (CRP) were measured by immunonephelometry and those of interleukin-6 (IL-6), intracellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) by enzyme-linked immunosorbent assay.Results:After adjusting for age, gender, body mass index, diabetes, smoking, use of statins, non-steroidal antiinflammatory drugs and aspirin, a higher consumption of fruits and cereals was associated with lower concentrations of IL-6 (P for trend 0.005;both). Subjects with the highest consumption of nuts and virgin olive oil showed the lowest concentrations of VCAM-1, ICAM-1, IL-6 and CRP; albeit only for ICAM-1 was this difference statistically significant in the case of nuts (for trend 0.003) and for VCAM-1 in the case of virgin olive oil (P for trend 0.02). Participants with higher adherence to the Mediterranean-type diet did not show significantly lower concentrations of inflammatory markers (P<0.1 for VCAM-1 and ICAM-1).Conclusions:The consumption of some typical Mediterranean foods (fruits, cereals, virgin olive oil and nuts) was associated with lower serum concentrations of inflammatory markers especially those related to endothelial function, in subjects with high cardiovascular risk living in a Mediterranean country.

Development of a short dietary intake questionnaire for the quantitative estimation of adherence to a cardioprotective Mediterranean diet

Our objective was to develop a short questionnaire that can be easily used to estimate quantitatively the level of adherence to cardioprotective Mediterranean diets. The short questionnaire assessed the consumption of cardioprotective elements included in the Mediterranean diet (olive oil, wine, fruits, vegetables, fish, legumes and whole-grain intake). A low consumption of meat or meat-products was also included in the composite score. The relative risk of myocardial infarction for each category of the composite score obtained (range 0–9) was computed using data from a case–control study that included 171 cases of first myocardial infarction and 171 matched controls. We found an adjusted odds ratio=0.18 (95% confidence interval (CI): 0.03–0.97; P=0.04) for those scoring 7–9 points when comparing them with those scoring 1–2 points. An increment of one point in the score was associated with an 18% reduction in the relative risk of myocardial infarction (P=0.05).Sponsorship: University of Navarre.

Adherence to a Mediterranean dietary pattern and weight gain in a follow-up study: the SUN cohort

Introduction:The promotion of Mediterranean Diets has generated some doubts, because of the concern that its high fat content might lead to the development of obesity.Methods:Longitudinal analysis of 6319 participants in the SUN cohort study. We used a validated semiquantitative food frequency questionnaire (136 items). Baseline adherence to a Mediterranean dietary pattern (MDP) was assessed using a score (score_1) including vegetables, fruits, cereals, nuts, pulses, fish, olive oil and moderate consumption of red wine (positively weighted), whereas meat and dairy products were negatively weighted. We assessed the association between the overall baseline adherence to the MDP (score_1) and subsequent weight change after 28 months of follow-up. We also built another score (score_2) to assess changes in diet during follow-up and appraised the association between the joint exposure to both scores and weight change during follow-up.Results:Participants in the first quartile of score_1 (lowest baseline adherence to MDP) showed a higher weight gain (+0.73 kg) than those in the top quartile (+0.45 kg). The results indicated an inverse dose–response relationship (P for trend=0.016). A similar inverse association was apparent when we used change in adherence to the MDP (score_2). However, both inverse associations did not remain statistically significant after adjusting for relevant confounders. Consumption of dairy products was inversely associated with weight gain.Conclusions:Although participants increased their average weight during the follow-up period, weight increments were smaller among those with a higher adherence to an ‘a priori’ defined MDP. Results did not remain statistically significant after multivariate adjustment.

Gender, age, socio-demographic and lifestyle factors associated with major dietary patterns in the Spanish Project SUN (Seguimiento Universidad de Navarra).

Objective: To ascertain the major dietary patterns in the cohort ‘SUN’ and to assess the association of several sociodemographic (including age and gender) and lifestyle variables with the adherence to these dietary patterns.Design: This study is a cross-sectional analysis of 3847 subjects (1587 men and 2260 women) belonging to a prospective cohort study based on self-reported questionnaires. A factor analysis based on 30 predefined food groups was conducted to ascertain the major dietary patterns in the cohort. Multiple regression models were fitted to assess the relationship between several sociodemographic and lifestyle variables and the adherence to these dietary patterns (measured using two scores with observed values ranging from −3.2 to +4.6 for the Western pattern and −3.1 to +5.5 for the Mediterranean pattern).Results: Two major dietary patterns were found. The first pattern was labelled as a ‘Western’ dietary pattern and the other as a ‘Spanish-Mediterranean’ dietary pattern. Younger subjects were more likely to follow a ‘Western’ dietary pattern; the coefficient representing the change for every 10 y increase in age was b=−0.24 (P<0.001) for men and b=−0.12 (P<0.001) for women. More physically active subjects were less likely to follow a ‘Western’ dietary pattern and more likely to follow a ‘Spanish-Mediterranean’ dietary pattern.Conclusion: An association between a higher level of physical activity during leisure time and adherence to a ‘Spanish-Mediterranean’ diet was apparent. However, the profile of being a young, sedentary and single male was identified as the most likely to exhibit a departure from the traditional ‘Spanish-Mediterranean’ diet and follow a ‘Western’ dietary pattern.Sponsorship: Departments of Health and Education of the Navarre Regional Government and FIS (Fondo de Investigaciones Sanitarias) of the Spanish Ministry of Health.

Mediterranean Diet and Stroke: Objectives and Design of the SUN Project

Purpose: The Mediterranean diet has been postulated as a protective factor against different diseases including stroke. Thus, an epidemiological study in a Mediterranean country, such as Spain, focused on diet may offer new insights of the potential benefits of this nutritional pattern to prevent the onset of cerebrovascular diseases. Methods: The SUN (“Seguimiento Universidad de Navarra”) project is a prospective study among Spanish university alumni, aimed to identify the dietary determinants of stroke, coronary disease and other disorders. Two pilot studies have been developed. The first pilot study was focused on the understanding of the questionnaire. The second study used a random sample to assess the response proportion and the feasibility of using a mailing system for following-up the cohort. The first informative results are expected to be available after the first four years of following-up the cohort (2005). Here, we report the description of the baseline diet of the first participants in the cohort using data from 1587 men and 2260 women. Results: The outcome of our pilot studies ensure the feasibility of a mail-based cohort. In the baseline assessment, we found a high consumption of olive oil (18.5 g/person/day), red wine (28.8 g/person/day), legumes (102.5 g/person/day), vegetables (507.8 g/person/day) and fruits (316.7 g/person/day), with a great between-subject variability. Also, the values for cereals (170.4 g/person/day), dairy products (239.3 g/person/day) and meat and meat products consumption (186 g/person/day) in this cohort were estimated. The coefficients of variation ranged in women from 56 (for vegetables) to 240% (for red wine) and in men from 62 to 180% (for these same two items)/reflecting a wide heterogeneity in the diet of participants. Conclusions: Although the participation was not high (22% according to the estimates of the pilot study), it was comparable to the proportion found in large previous cohorts such as the Nurses-II Health Study (24%). The sharp contrast in dietary habits between the US and Spain together with the high between-subjects variability we have found in our Spanish cohort provides an exceptional opportunity to assess the aspects of the Mediterranean diet, which may be protective against stroke and other neurological disorders.

Adherence to the Mediterranean diet and risk of metabolic syndrome and its components

BACKGROUND AND AIMS The role of diet in the aetiology of metabolic syndrome (MetS) is not well understood. The aim of the present study was to evaluate the relationship between adherence to the Mediterranean diet (MedDiet) and MetS. METHODS AND RESULTS A cross-sectional study was conducted with 808 high cardiovascular risk participants of the Reus PREDIMED Centre. MetS was defined by the updated National Cholesterol and Education Program Adult Treatment Panel III criteria. An inverse association between quartiles of adherence to the MedDiet (14-point score) and the prevalence of MetS (P for trend<0.001) was observed. After adjusting for age, sex, total energy intake, smoking status and physical activity, participants with the highest score of adherence to the MedDiet (>/=9 points) had the lowest odds ratio of having MetS (OR [95% CI] of 0.44 [0.27-0.70]) compared to those in the lowest quartile. Participants with the highest MedDiet adherence had 47 and 54% lower odds of having low HDL-c and hypertriglyceridemia MetS criteria, respectively, than those in the lowest quartile. Some components of the MedDiet, such as olive oil, legumes and red wine were associated with lower prevalence of MetS. CONCLUSION Higher adherence to a Mediterranean diet is associated with a significantly lower odds ratio of having MetS in a population with a high risk of cardiovascular disease.

A 3 years follow-up of a Mediterranean diet rich in virgin olive oil is associated with high plasma antioxidant capacity and reduced body weight gain

Background/Objectives:The aim of this study was to analyze the influence of a Mediterranean dietary pattern on plasma total antioxidant capacity (TAC) after 3 years of intervention and the associations with adiposity indexes in a randomized dietary trial (PREDIMED trial) with high cardiovascular risk patients.Subjects/Methods:187 subjects were randomly selected from the PREDIMED-UNAV center after they completed 3-year intervention program. Participants were following a Mediterranean-style diet with high intake of virgin olive oil or high intake of nuts, or a conventional low-fat diet. Adiposity indexes were measured at baseline and at year 3. Plasma TAC was evaluated using a commercially available colorimetric assay kit.Results:Plasma TAC in the control, olive oil and nuts groups was 2.01±0.15, 3.51±0.14 and 3.02±0.14 mM Trolox, respectively after adjusting for age and sex. The differences between the Mediterranean diet and control groups were statistically significant (P<0.001). Moreover higher levels of TAC were significantly associated with a reduction in body weight after 3 years of intervention among subjects allocated to the virgin olive oil group (B=−1.306; 95% CI=−2.439 to −0.173; P=0.025, after adjusting for age, sex and baseline body mass index).Conclusions:Mediterranean diet, especially rich in virgin olive oil, is associated with higher levels of plasma antioxidant capacity. Plasma TAC is related to a reduction in body weight after 3 years of intervention in a high cardiovascular risk population with a Mediterranean-style diet rich in virgin olive oil.

Dietary intake and major food sources of polyphenols in a Spanish population at high cardiovascular risk: The PREDIMED study

BACKGROUND AND AIMS Epidemiological data have shown an inverse association between the consumption of polyphenol-rich foods and the risk of cardiovascular disease or overall mortality. A comprehensive estimation of individual polyphenol intake in nutritional cohorts is needed to gain a better understanding of this association. The aim of this study was to estimate the quantitative intake of polyphenols and the major dietary sources in the PREDIMED (PREvención con DIeta MEDiterránea) cohort using individual food consumption records. METHODS AND RESULTS The PREDIMED study is a large, parallel-group, multicentre, randomised, controlled 5-year feeding trial aimed at assessing the effects of the Mediterranean diet on the primary prevention of cardiovascular disease. A total of 7200 participants, aged 55-80 years, completed a validated 1-year food frequency questionnaire (FFQ) at baseline. Polyphenol consumption was calculated by matching food consumption data from the FFQ with the recently developed Phenol-Explorer database on polyphenol content in foods. The mean total polyphenol intake was 820 ± 323 mg day⁻¹ (443 ± 218 mg day⁻¹ of flavonoids and 304 ± 156 mg day⁻¹ of phenolic acids). Hydroxycinnamic acids were the phenolic group with the highest consumption and 5-caffeoylquinic acid was the most abundantly ingested individual polyphenol. The consumption of olives and olive oil was a differentiating factor in the phenolic profile of this Spanish population compared with other countries. CONCLUSION In Mediterranean countries, such as Spain, the main dietary source of polyphenols is coffee and fruits, but the most important differentiating factor with respect to other countries is the consumption of polyphenols from olives and olive oil.