Stefaan De Henauw

Vitamin D deficiency in Europe: pandemic?

Background: Vitamin D deficiency has been described as being pandemic, but serum 25-hydroxyvitamin D [25(OH)D] distribution data for the European Union are of very variable quality. The NIH-led international Vitamin D Standardization Program (VDSP) has developed protocols for standardizing existing 25(OH)D values from national health/nutrition surveys. Objective: This study applied VDSP protocols to serum 25(OH)D data from representative childhood/teenage and adult/older adult European populations, representing a sizable geographical footprint, to better quantify the prevalence of vitamin D deficiency in Europe. Design: The VDSP protocols were applied in 14 population studies [reanalysis of subsets of serum 25(OH)D in 11 studies and complete analysis of all samples from 3 studies that had not previously measured it] by using certified liquid chromatography–tandem mass spectrometry on biobanked sera. These data were combined with standardized serum 25(OH)D data from 4 previously standardized studies (for a total n = 55,844). Prevalence estimates of vitamin D deficiency [using various serum 25(OH)D thresholds] were generated on the basis of standardized 25(OH)D data. Results: An overall pooled estimate, irrespective of age group, ethnic mix, and latitude of study populations, showed that 13.0% of the 55,844 European individuals had serum 25(OH)D concentrations <30 nmol/L on average in the year, with 17.7% and 8.3% in those sampled during the extended winter (October–March) and summer (April–November) periods, respectively. According to an alternate suggested definition of vitamin D deficiency (<50 nmol/L), the prevalence was 40.4%. Dark-skinned ethnic subgroups had much higher (3- to 71-fold) prevalence of serum 25(OH)D <30 nmol/L than did white populations. Conclusions: Vitamin D deficiency is evident throughout the European population at prevalence rates that are concerning and that require action from a public health perspective. What direction these strategies take will depend on European policy but should aim to ensure vitamin D intakes that are protective against vitamin D deficiency in the majority of the European population.

Consumer perception versus scientific evidence about health benefits and safety risks from fish consumption.

OBJECTIVE To investigate the gap between consumer perception and scientific evidence related to health benefits and safety risks from fish consumption. DESIGN Consumer perceptions from a cross-sectional survey in March 2003 in Belgium were compared with scientific evidence based on a literature review. METHOD A quota sampling procedure was used with age as quota control variable. Subjects completed a self-administered questionnaire including health benefit beliefs from fish, fish content and effect beliefs for nutrients and harmful substances. SUBJECTS Adults (n=429), who were the main person responsible for food purchasing in the household (284 women; 145 men), aged 18-83 years, from different regional, education, family size and income groups. RESULTS Fish is predominantly perceived as a healthy food that reduces risk for coronary heart disease, which corroborates scientific evidence. This perception is stronger among women than among men. In contrast with scientific evidence, 46% of the consumers believe that fish contains dietary fibre, whereas less than one-third is aware that fish contains omega-3 fatty acids and that this nutrient has a positive impact on human health. The gap between perception and evidence is larger among consumers with lower education. In general, consumers are better aware of the content and effect of harmful substances than of nutrients in fish. CONCLUSIONS Despite conclusive evidence about the content and positive effect of omega-3 fatty acids in fish, related consumer awareness and beliefs are poor and often wrong. This study exemplifies the need for nutrition education and more effective communication about the health benefits of fish consumption.

Clustering patterns of physical activity, sedentary and dietary behavior among European adolescents: The HELENA study

BackgroundEvidence suggests possible synergetic effects of multiple lifestyle behaviors on health risks like obesity and other health outcomes. A better insight in the clustering of those behaviors, could help to identify groups who are at risk in developing chronic diseases. This study examines the prevalence and clustering of physical activity, sedentary and dietary patterns among European adolescents and investigates if the identified clusters could be characterized by socio-demographic factors.MethodsThe study comprised a total of 2084 adolescents (45.6% male), from eight European cities participating in the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) study. Physical activity and sedentary behavior were measured using self-reported questionnaires and diet quality was assessed based on dietary recall. Based on the results of those three indices, cluster analyses were performed. To identify gender differences and associations with socio-demographic variables, chi-square tests were executed.ResultsFive stable and meaningful clusters were found. Only 18% of the adolescents showed healthy and 21% unhealthy scores on all three included indices. Males were highly presented in the cluster with high levels of moderate to vigorous physical activity (MVPA) and low quality diets. The clusters with low levels of MVPA and high quality diets comprised more female adolescents. Adolescents with low educated parents had diets of lower quality and spent more time in sedentary activities. In addition, the clusters with high levels of MVPA comprised more adolescents of the younger age category.ConclusionIn order to develop effective primary prevention strategies, it would be important to consider multiple health indices when identifying high risk groups.

Single nucleotide polymorphisms in the FADS gene cluster are associated with delta-5 and delta-6 desaturase activities estimated by serum fatty acid ratios

Genetic variability in the FADS1-FADS2 gene cluster [encoding delta-5 (D5D) and delta-6 (D6D) desaturases] has been associated with plasma long-chain PUFA (LCPUFA) and lipid levels in adults. To better understand these relationships, we further characterized the association between FADS1-FADS2 genetic variability and D5D and D6D activities in adolescents. Thirteen single nucleotide polymorphisms (SNPs) were genotyped in 1,144 European adolescents (mean ± SD age: 14.7 ± 1.4 y). Serum phospholipid fatty acid levels were analyzed using gas chromatography. D5D and D6D activities were estimated from the C20:4n-6/C20:3n-6 and C20:3n-6/C18:2n-6 ratios, respectively. Minor alleles of nine SNPs were associated with higher 18:2n-6 levels (1.9E-18 ≤ P ≤ 6.1E-5), lower C20:4n-6 levels (7.1E-69 ≤ P ≤ 1.2E-12), and lower D5D activity (7.2E-44 ≤ P ≤ 4.4E-5). All haplotypes carrying the rs174546 minor allele were associated with lower D5D activity, suggesting that this SNP is in linkage disequilibrium with a functional SNP within FADS1. In contrast, only the rs968567 minor allele was associated with higher D6D activity (P = 1.5E-6). This finding agrees with an earlier in vitro study showing that the minor allele of rs968567 is associated with a higher FADS2 promoter activity. These results suggest that rare alleles of several SNPs in the FADS gene cluster are associated with higher D6D activity and lower D5D activity in European adolescents.

Dietary intakes and food sources of fatty acids for Belgian women, focused on n-6 and n-3 polyunsaturated fatty acids.

The intake of fat, saturated and monounsaturated FA (SFA and MUFA), and omega-6 and omega-3 PUFA has been estimated in 641 Belgian women (age 18-39 y). Their food intake was recorded using a 2-d food diary. The PUFA included were linoleic (LA), alpha-linolenic (LNA), arachidonic (AA), eicosapentaeonoic (EPA), docosapentaenoic (DPA) and docosahexaenoic (DHA) acids. The mean total fat intake corresponded to 34.3% of total energy intake (E). The mean intake of the FA groups corresponded to 13.7%, 13.1%, and 6.0% of E, for SFA, MUFA, and PUFA, respectively. The mean intake of LA was 5.3% of E and of LNA was 0.6% of E, with a mean LA/LNA ratio of 8.7. The mean intake of AA was 0.03% of E. The mean intake of EPA, DPA, and DHA was 0.4%, 0.01%, and 0.06% of E, respectively. According to the Belgian recommendations, the total fat and SFA intake was too high for about three-quarters of the population. The mean LA and overall n-6 PUFA intake corresponded with the recommendation, with part of the population exceeding the upper level. Conversely, the population showed a large deficit for LNA and n-3 PUFA. The major food source for LA and LNA was fats and oils, followed by cereal products. The main sources of long-chain PUFA were fish and seafood, and meat, poultry, and eggs. From a public health perspective, it seems desirable to tackle the problem of low n-3 PUFA intake.

Perceived Importance of Sustainability and Ethics Related to Fish: A Consumer Behavior Perspective

Abstract Although sustainability and ethics are of increasing public importance, little research has been conducted to reveal its association with fish consumer behavior. Cross-sectional data were collected through a postal self-administered survey (June 2005) from a sample of 381 Flemish women aged 20–50 years. Consumers attach high perceived importance to sustainability and ethics related to fish. However, this perceived importance is neither correlated with fish consumption frequency nor with general attitude toward eating fish. Refusing to eat wild fish is grounded in sustainability and ethical concerns, whereas the decision not to eat farmed fish is associated with a lower expected intrinsic quality rather than shaped by importance attached to sustainability and ethical issues.

Food intake of European adolescents in the light of different food-based dietary guidelines: results of the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study

OBJECTIVE Since inadequate food consumption patterns during adolescence are not only linked with the occurrence of obesity in youth but also with the subsequent risk of developing diseases in adulthood, the establishment and maintenance of a healthy diet early in life is of great public health importance. Therefore, the aim of the present study was to describe and evaluate the food consumption of a well-characterized sample of European adolescents against food-based dietary guidelines for the first time. DESIGN The HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study is a cross-sectional study, whose main objective was to obtain comparable data on a variety of nutritional and health-related parameters in adolescents aged 12·5-17·5 years. SETTING Ten cities in Europe. SUBJECTS The initial sample consisted of more than 3000 European adolescents. Among these, 1593 adolescents (54 % female) had sufficient and plausible dietary data on energy and food intakes from two 24 h recalls using the HELENA-DIAT software. RESULTS Food intake of adolescents in Europe is not optimal compared with the two food-based dietary guidelines, Optimized Mixed Diet and Food Guide Pyramid, examined in this study. Adolescents eat half of the recommended amount of fruit and vegetables and less than two-thirds of the recommended amount of milk (and milk products), but consume much more meat (and meat products), fats and sweets than recommended. However, median total energy intake may be estimated to be nearly in line with the recommendations. CONCLUSION The results urge the need to improve the dietary habits of adolescents in order to maintain health in later life.

Determinants of nutrition knowledge in young and middle-aged Belgian women and the association with their dietary behaviour

The present study investigated the role of socio-demographic and lifestyle determinants on the nutrition knowledge of Belgian women and the association between their knowledge and dietary behaviour. A total of 803 women, aged 18-39 years, were included in a cross-sectional study and completed a general and nutrition knowledge questionnaire and a 2-day food record. Their height and weight were measured under standardised conditions. Linear regression models showed independent significant associations between the following determinants and the womens nutrition knowledge (in order of importance): educational level, age, kind of occupation, smoking behaviour, and work status. Inconsistent or no associations were found for body mass index, physical activity, living situation, and whether or not they had children. The investigated determinants accounted for 13-14.5% of variance in total nutrition knowledge. A rise in nutrition knowledge was associated with a significant rise in consumption of vegetables and fruit, but no differences were seen for other dietary indicators. Most important determinants of the womens nutrition knowledge were educational level, age and their kind of occupation. Women who had better knowledge of nutrition also exhibited better dietary behaviour, thus underlying the importance of nutrition education for improving dietary behaviour.

Attenuation of the effect of the FTO rs9939609 polymorphism on total and central body fat by physical activity in adolescents: the HELENA study.

OBJECTIVE To examine whether physical activity attenuates the effect of the FTO rs9939609 polymorphism on body fat estimates in adolescents. DESIGN Cross-sectional study. SETTING Athens, Greece; Dortmund, Germany; Ghent, Belgium; Heraklion, Greece; Lille, France; Pécs, Hungary; Rome, Italy; Stockholm, Sweden; Vienna, Austria; and Zaragoza, Spain, from October 2006 to December 2007. PARTICIPANTS Adolescents from the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study (n = 752). MAIN EXPOSURE Physical activity. MAIN OUTCOME MEASURES The FTO rs9939609 polymorphism was genotyped. Physical activity was assessed by accelerometry. We measured weight, height, waist circumference, and triceps and subscapular skinfolds; body mass index (BMI [calculated as weight in kilograms divided by height in meters squared]) and body fat percentage were calculated. RESULTS The A allele of the FTO polymorphism was significantly associated with higher BMI (+0.42 per risk allele), higher body fat percentage (+1.03% per risk allele), and higher waist circumference (+0.85 cm per risk allele). We detected significant or borderline gene x physical activity interactions for the studied body fat estimates (for interaction, P = .02, .06, and .10 for BMI, body fat percentage, and waist circumference, respectively). Indeed, the effect of the FTO rs9939609 polymorphism on these body fat parameters was much lower in adolescents who met the daily physical activity recommendations (ie, >/=60 min/d of moderate to vigorous physical activity) compared with those who did not: +0.17 vs +0.65 per risk allele in BMI, respectively; +0.40% vs +1.70% per risk allele in body fat percentage, respectively; and +0.60 vs +1.15 cm per risk allele in waist circumference, respectively. CONCLUSION Adolescents meeting the daily physical activity recommendations may overcome the effect of the FTO rs9939609 polymorphism on obesity-related traits.

Assessment of diet, physical activity and biological, social and environmental factors in a multi-centre European project on diet- and lifestyle-related disorders in children (IDEFICS)

Obesity is a major public health problem in developed countries. We present a European project, called Identification and Prevention of Dietary and Lifestyle-induced Health Effects in Children and Infants (IDEFICS), that focuses on diet- and lifestyle-related diseases in children. This paper outlines methodological aspects and means of quality control in IDEFICS. IDEFICS will use a multicentre survey design of a population-based cohort of about 17,000 2- to 10-year-old children in nine European countries (Belgium, Cyprus, Estonia, Germany, Greece, Hungary, Italy, Spain and Sweden). The project will investigate the impact of dietary factors such as food intake and food preferences, lifestyle factors such as physical activity, psychosocial factors and genetic factors on the development of obesity and other selected diet- and lifestyle-related disorders. An intervention study will be set up in pre-school and primary school settings in eight of the survey centres. Standardised survey instruments will be designed during the first phase of the project and applied in the surveys by all centres. Standard operation procedures (SOPs) will be developed, as well as a plan for training the personnel involved in the surveys. These activities will be accompanied by a quality control strategy that will encompass the evaluation of process and result quality throughout the project. IDEFICS will develop comparable Europe-wide health indicators and instruments for data collection among young children. Establishment of a new European cohort within IDEFICS will provide a unique opportunity to document the development of the obesity epidemic in the current generation of young Europeans and investigate the impact of primary prevention in European children populations.