M Cuenca-García

Is dairy consumption associated with low cardiovascular disease risk in European adolescents? Results from the HELENA Study

Although there is no clear evidence of the role of dairy consumption on cardiovascular disease (CVD) risk development in adults, several studies have suggested dairy consumption to have a protective effect. Limited evidence on the relationship between milk and dairy products consumption and CVD risk factors among adolescents.

Increased sedentary behaviour is associated with unhealthy dietary patterns in European adolescents participating in the HELENA study

Background/Objectives:To assess dietary patterns (DPs) in European adolescents and to examine their relationship with several indicators of sedentary behaviour.Subjects/Methods:A multinational cross-sectional study was carried out in 2202 adolescents (45.4% boys) aged 12.5–17.5 years. A self-reported questionnaire with information on sedentary behaviours, separately for weekdays and weekend days, and two non-consecutive 24u2009h-recalls were used. Principal component analysis was used to obtain DPs, and linear regression examined the association between DPs scores and sedentary behaviour.Results:Four DPs for boys (‘plant based’, ‘snacking’, ‘breakfast’ and ‘health conscious’) and five DPs for girls (‘confectionary and snacking’, ‘plant based’, ‘breakfast’, ‘animal protein’ and ‘health conscious’) were obtained. Boys who spent >4u2009h/day watching television (TV) had lower adherence to the ‘plant based’, ‘breakfast’ and ‘health conscious’ DPs, and higher adherence to the ‘snacking’ DP. Higher computer use and internet use for recreational reason were associated with higher adherence to the ‘snacking’ DP. In girls, TV viewing and using internet for recreational reasons for >4u2009h/day was associated with higher adherence to the ‘confectionary and snacking’ and lower adherence with ‘health conscious’ DP. Also, studying between 2 and 4u2009h during weekend days was associated with lower adherence to the ‘snacking’ and with higher adherence to the ‘plant based’ and ‘breakfast’ DPs.Conclusion:Adolescents’ DPs are related with the time spent in several sedentary behaviours. Such findings may help to generate interventions focusing on decreasing unhealthy dietary habits and specific sedentary behaviours.

Mechanisms of stress, energy homeostasis and insulin resistance in European adolescents – the HELENA study

BACKGROUND AND AIMSnStress is hypothesized to facilitate the development of obesity, whose the foundations are already set during childhood and adolescence. We investigated the relationship between the stress-system, selected mechanisms of energy homeostasis and insulin resistance (IR) in a sample of European adolescents.nnnMETHODS AND RESULTSnWithin HELENA-CSS, 723 adolescents (12.5-17.5 years) from 10 European cities provided all the necessary data for this study. Fasting blood samples were collected for cortisol, leptin, insulin and glucose analysis. HOMA-IR was calculated from insulin and glucose concentrations. Adolescents body fat (BF) %, age and duration of exclusive breastfeeding were assessed. For boys and girls separately, the relationship of cortisol with leptin, insulin, glucose and HOMA-IR was examined by computing Pearson correlation coefficients and Hierarchical Linear Models (HLMs), with city as cluster unit, adjusting for age, BF% and duration of exclusive breastfeeding. In boys, Pearson correlation coefficients illustrated positive correlations of cortisol with insulin (r = 0.144; p = 0.013), glucose (r = 0.315; p < 0.001) and HOMA-IR (r = 0.180; p = 0.002), whilst in girls, this positive relationship was observed for leptin (r = 0.147; p = 0.002), insulin (r = 0.095; p = 0.050) and HOMA-IR (r = 0.099; p = 0.041), but not for glucose (r = 0.054; p = 0.265). Observed associations were independent of adolescents age, BF% and duration of exclusive breastfeeding after computing HLMs.nnnCONCLUSIONnThis study suggests that the stress-system is positively related to mechanisms of energy homeostasis and IR in European adolescents, and reveals a potential small gender difference in this relationship. The hypothesis that stress might facilitate the development of obesity during adolescence is supported.

Intake and dietary sources of haem and non-haem iron among European adolescents and their association with iron status and different lifestyle and socio-economic factors

Background/Objectives:Adolescents are at risk of iron deficiency because of their high iron requirements. The aims of this study were: (1) to assess iron intake, its determinants and its most important food sources and; (2) to evaluate the relation of iron intake and status in European adolescents.Subjects/Methods:Two non-consecutive 24-h recalls were completed by a computerised tool. The socio-demographic and socio-economic data were collected by a self-reported questionnaire. Weight and height were measured. A distinction was made between haem and non-haem iron.Results:The total iron intake was significantly higher among boys (13.8u2009mg/day; n=1077) than girls (11.0u2009mg/day; n=1253). About 97.3% of the boys and 87.8% of the girls met the estimated average requirement, and 72.4% of the boys and 13.7% of the girls met the recommendation for bio-available iron intake. The ratio of haem/non-haem iron intake was lower for girls than boys. Meat (19.2; 76%) and bread and rolls (12.6;3.9%) contributed most to total and haem iron intake. Bread and rolls (13.8%) and meat (10.8%) contributed most to non-haem iron intake. Age, sex and body mass index were associated with iron intake. Only red blood cell concentration was significantly negatively associated with total, haem and non-haem iron intake.Conclusion:Girls had lower iron intakes and ratio of haem/non-haem iron intake than boys. The main total iron and haem iron source was meat, while the main non-haem iron source was bread and rolls. Adolescent girls may be a group at risk for iron deficiency. Consequently, special attention and strategies are needed in order to improve iron intakes during adolescence.

Diet quality and attention capacity in European adolescents: the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study

Adolescence represents an important period for the development of executive functions, which are a set of important cognitive processes including attentional control. However, very little is known regarding the associations of nutrition with components of executive functions in adolescence. Thus, the aim of this study was to investigate associations of dietary patterns and macronutrient composition with attention capacity in European adolescents. This cross-sectional study included 384 (165 boys and 219 girls) adolescents, aged 12·5-17·5 years, from five European countries in the Healthy Lifestyle in Europe by Nutrition in Adolescence study. Attention capacity was examined using the d2 Test of Attention. Dietary intake was assessed through two non-consecutive 24 h recalls using a computer-based self-administered tool. Three dietary patterns (diet quality index, ideal diet score and Mediterranean diet score) and macronutrient/fibre intakes were calculated. Linear regression analysis was conducted adjusting for age, sex, BMI, maternal education, family affluence scale, study centre and energy intake (only for Mediterranean diet score). In these adjusted regression analyses, higher diet quality index for adolescents and ideal diet score were associated with a higher attention capacity (standardised β=0·16, P=0·002 and β=0·15, P=0·005, respectively). Conversely, Mediterranean diet score or macronutrient/fibre intake were not associated with attention capacity (P>0·05). Our results suggest that healthier dietary patterns, as indicated by higher diet quality index and ideal diet score, were associated with attention capacity in adolescence. Intervention studies investigating a causal relationship between diet quality and attention are warranted.

The role of dietary fat on the association between dietary amino acids and serum lipid profile in European adolescents participating in the HELENA Study

Background/objectives:The objective of this study was to examine the relationship between amino acid (AA) intake and serum lipid profile in European adolescents from eight European cities participating in the cross-sectional (2006–2007) HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) study, and to assess whether this association was independent of total fat intake.Subjects/methods:Diet, skinfold thickness, triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-c), TC/HDL-c ratio, low-density lipoprotein cholesterol (LDL-c), apolipoprotein B (Apo B), apolipoprotein A1 (Apo A1) and Apo B/Apo A1 ratio were measured in 454 12.5- to 17.5-year-old adolescents (44% boys). Intake was assessed via two non-consecutive 24-h dietary recalls. Data on maternal education and sedentary behaviors were obtained via questionnaires. Physical activity was objectively measured by accelerometry.Results:Alanine, arginine, asparaginic acid, glycine, histidine, lysine and serine intakes were inversely associated with serum TG concentrations in both boys and girls. Intake of other AA like alanine and/or arginine was also inversely associated with serum TC, LDL-c and Apo B/Apo A1 ratio only in girls. An inverse association was observed between intakes of alanine, isoleucine, leucine, methionine, serine, tryptophan, tyrosine and valine and TC/HDL-c ratio among female adolescents. Similar results were found in males for serine and tryptophan intakes. It is noteworthy, however, that associations were no longer significant in both genders when total fat intake was considered as a confounding factor.Conclusions:In this sample of adolescents, the association between AA intakes and serum lipid profile did not persist when dietary fat was considered. Therefore, dietary interventions and health promotion activities should focus on fat intake to improve lipid profile and potentially prevent cardiovascular disease.

Fruit and vegetables consumption is associated with higher vitamin intake and blood vitamin status among European adolescents

Background/Objectives:Current research in adults indicates that fruit and vegetable (FAV) consumption increases serum levels of vitamins C, E and folate of β-carotene and reduces homocysteine concentrations. The aim of the present study was to examine the association of FAV consumption on vitamin intakes and their impact on blood vitamin concentrations in European adolescents.Subject/Methods:This multi-center cross-sectional study included 702 (53.7% females) adolescents, aged 12.50–17.49 years, from 10 European cities. Two independent self-administered 24u2009h dietary recalls were used to estimate the adolescent’s diet. The total energy, vitamins and FAV consumption were calculated. Adolescents were categorized into three groups: (i) very low FAV intake (<200u2009g/day); (ii) low FAV consumption (200–399u2009g/day) and (iii) adequate FAV consumption (⩾400u2009g/day). Adolescent’s fasted blood samples were taken for their analysis on vitamin concentrations.Results:The main results showed that those adolescents meeting the FAV recommendation, classified as FAV adequate consumers, presented higher intake of energy and some vitamins as B6, total folic acid, C, E and β-carotene compared with FAV very low consumers (P<0.05). Regarding their blood status, male adolescents who had a very low FAV consumption presented lower plasma folate, RBC folate blood concentrations compared with adequate FAV consumers (P<0.05). Female adequate FAV consumers had higher concentrations of pyridoxal phosphate (PLP), plasma folate, RBC folate, vitamin C, β-carotene and α-tocopherol compared with very low and low consumers (P<0.05).Conclusions:Having a FAV dairy intake above 400u2009g/day is associated with higher vitamin intake and blood vitamin concentrations, especially for antioxidant and B-vitamins concentrations.