Healthy Lifestyle In Europe By Nutrition In Adolescence Study Research Articles

Development of a genetic risk score to predict the risk of hypertension in European adolescents from the HELENA study.

From genome wide association study (GWAS) a large number of single nucleotide polymorphisms (SNPs) have previously been associated with blood pressure (BP) levels. A combination of SNPs, forming a genetic risk score (GRS) could be considered as a useful genetic tool to identify individuals at risk of developing hypertension from early stages in life. Therefore, the aim of our study was to build a GRS being able to predict the genetic predisposition to hypertension (HTN) in European adolescents. Data were extracted from the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) cross-sectional study. A total of 869 adolescents (53% female), aged 12.5-17.5, with complete genetic and BP information were included. The sample was divided into altered (≥130 mmHg for systolic and/or ≥80 mmHg for diastolic) or normal BP. Based on the literature, a total of 1.534 SNPs from 57 candidate genes related with BP were selected from the HELENA GWAS database. From 1,534 SNPs available, An initial screening of SNPs univariately associated with HTN (p < 0.10) was established, to finally obtain a number of 16 SNPs significantly associated with HTN (p < 0.05) in the multivariate model. The unweighted GRS (uGRS) and weighted GRS (wGRS) were estimated. To validate the GRSs, the area under the curve (AUC) was explored using ten-fold internal cross-validation for uGRS (0.802) and wGRS (0.777). Further covariates of interest were added to the analyses, obtaining a higher predictive ability (AUC values of uGRS: 0.879; wGRS: 0.881 for BMI z-score). Furthermore, the differences between AUCs obtained with and without the addition of covariates were statistically significant (p < 0.05). Both GRSs, the uGRS and wGRS, could be useful to evaluate the predisposition to hypertension in European adolescents.

Relative validity of the Planetary Health Diet Index by comparison with usual nutrient intakes, plasma food consumption biomarkers, and adherence to the Mediterranean diet among European adolescents: the HELENA study.

The EAT-Lancet Commission proposed an evidence-based global reference diet to improve human health within planetary boundaries. Recently, the Planetary Health Diet Index (PHDI) was developed based on the EAT-Lancet recommendations and validated among Brazilian adults. However, the relative validity of the PHDI in adolescents has yet to be assessed. Thus, we aimed to evaluate the relative validity of the PHDI in European adolescents. We used cross-sectional data from 1804 adolescents (12.5-17.5years) enrolled in the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study. The PHDI (0-150 points) was calculated based on dietary intake data from two non-consecutive 24-h dietary recalls. Associations between the PHDI and usual nutrient intakes, plasma food consumption biomarkers, and adherence to the Mediterranean diet were evaluated using multivariable-adjusted mixed-effects linear regression models. Higher PHDI score was associated with greater intakes of nutrients predominantly from plant-source foods, such as vegetable protein, vitamin E, and folate and with lower intake of nutrients predominately from animal-source foods, such as total and saturated fat, cholesterol, and animal protein. Furthermore, a higher PHDI score was also positively associated with plasma β-carotene, vitamin C, vitamin D, folate, and ferritin concentrations, while negatively associated with trans-fatty acids concentration. Moreover, higher PHDI was related to a greater adherence to the Mediterranean dietary pattern. The PHDI showed good relative validity among adolescents in the HELENA study. Hence, future research should assess adherence to the PHDI and long-term health outcomes.

Associations between food portion sizes, insulin resistance, VO2 max and metabolic syndrome in European adolescents: The HELENA study

Background and aimsThis study aims to examine the associations of food portion size (PS) with markers of insulin resistance (IR) and clustered of metabolic risk score in European adolescents. MethodsA total of 495 adolescents (53.5% females) from the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study were included. The association between PS from food groups and homeostasis model assessment of insulin resistance (HOMA-IR) index, VO2 max, and metabolic risk score was assessed by multilinear regression analysis adjusting for several confounders. Analysis of covariance (ANCOVA) was used to determine the mean differences of food PS from food groups by HOMA-IR cutoff categories by using maternal education as a covariable. ResultsLarger PS from vegetables in both gender and milk, yoghurt, and milk beverages in males were associated with higher VO2 max, while larger PS from margarines and vegetable oils were associated with lower VO2 max (p < 0.05). Males who consumed larger PS from fish and fish products; meat substitutes, nuts, and pulses; cakes, pies, and biscuits; and sugar, honey, jams, and chocolate have a higher metabolic risk score (p < 0.05). Males with lower HOMA-IR cutoff values consumed larger PS from vegetables, milk, yoghurt, and milk beverages (p < 0.05). Females with lower HOMA-IR cutoff values consumed larger PS from breakfast cereals, while those with higher HOMA-IR cutoff values consumed larger PS from butter and animal fats (p = 0.018). ConclusionThe results show that larger PS from dairy products, cereals, and high energy dense foods are a significant determinant of IR and VO2 max, and larger PS from food with higher content of sugar were associated with higher metabolic risk score.

High Fructose Intake Contributes to Elevated Diastolic Blood Pressure in Adolescent Girls: Results from The HELENA Study.

Background: The association between high fructose consumption and elevated blood pressure continues to be controversial, especially in adolescence. The aim of this study was to assess the association between fructose consumption and elevated blood pressure in an European adolescent population. Methods: A total of 1733 adolescents (mean ± SD age: 14.7 ± 1.2; percentage of girls: 52.8%) were analysed from the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study in eight European countries. Blood pressure was measured using validated devices and methods for measuring systolic blood pressure (SBP) and diastolic blood pressure (DBP). Dietary data were recorded via repeated 24 h recalls (using specifically developed HELENA–DIAT software) and converted into pure fructose (monosaccharide form) and total fructose exposure (pure fructose + fructose from sucrose) intake using a specific fructose composition database. Food categories were separated at posteriori in natural vs. were non-natural foods. Elevated BP was defined according to the 90th percentile cut-off values and was compared according to tertiles of fructose intake using univariable and multivariable mixed logistic regression models taking into account confounding factors: centre, sex, age and z-score–BMI, MVPA (Moderate to Vigorous Physical Activity) duration, tobacco consumption, salt intake and energy intake. Results: Pure fructose from non-natural foods was only associated with elevated DBP (DBP above the 10th percentile in the highest consuming girls (OR = 2.27 (1.17–4.40); p = 0.015) after adjustment for cofounding factors. Conclusions: Consuming high quantities of non-natural foods was associated with elevated DBP in adolescent girls, which was in part due to high fructose levels in these foods categories. The consumption of natural foods containing fructose, such as whole fruits, does not impact blood pressure and should continue to remain a healthy dietary habit.

Development of a Genetic Risk Score to predict the risk of overweight and obesity in European adolescents from the HELENA study

Obesity is the result of interactions between genes and environmental factors. Since monogenic etiology is only known in some obesity-related genes, a genetic risk score (GRS) could be useful to determine the genetic predisposition to obesity. Therefore, the aim of our study was to build a GRS able to predict genetic predisposition to overweight and obesity in European adolescents. A total of 1069 adolescents (51.3% female), aged 11–19 years participating in the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) cross-sectional study were genotyped. The sample was divided in non-overweight (non-OW) and overweight/obesity (OW/OB). From 611 single nucleotide polymorphisms (SNP) available, a first screening of 104 SNPs univariately associated with obesity (p < 0.20) was established selecting 21 significant SNPs (p < 0.05) in the multivariate model. Unweighted GRS (uGRS) was calculated by summing the number of risk alleles and weighted GRS (wGRS) by multiplying the risk alleles to each estimated coefficient. The area under curve (AUC) was calculated in uGRS (0.723) and wGRS (0.734) using tenfold internal cross-validation. Both uGRS and wGRS were significantly associated with body mass index (BMI) (p < .001). Both GRSs could potentially be considered as useful genetic tools to evaluate individual’s predisposition to overweight/obesity in European adolescents.

Total Polyphenol Intake Is Inversely Associated with a Pro/Anti-Inflammatory Biomarker Ratio in European Adolescents of the HELENA Study

Although high dietary polyphenol intake is negatively associated with risk of certain inflammation-associated chronic diseases, the underlying mechanisms are not fully understood and few studies have explored this in adolescents. This study aimed to evaluate the association between intakes of total polyphenols, polyphenol classes, and the 10 most commonly consumed individual polyphenols with inflammatory biomarkers in the blood of European adolescents. In the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) Study, 526 adolescents (54% girls; 12.5-17.5 y) had data on inflammatory biomarkers and polyphenol intake from 2 nonconsecutive 24-h recalls via matching with the Phenol-Explorer database. Inflammatory biomarkers in serum were IL-1, IL-2, IL-4, IL-5, IL-6, IL-10, transforming growth factor β1 (TGF-β1), TNF-α, IFN-γ, soluble vascular adhesion molecule 1 (sVCAM-1), soluble intercellular adhesion molecule 1 (sICAM-1), soluble E-selectin (sE-selectin), white blood cells, lymphocytes, T cells, and C-reactive protein. Multilevel linear models were used to test associations of polyphenol intake with a pro/anti-inflammatory biomarker ratio [(zTNF-α + zIL-6+zIL-1)/3/zIL-10] as well as with separate inflammatory biomarkers, adjusted for sociodemographic variables, diet inflammation index, BMI z score, and serum triglycerides. The pro/anti-inflammatory biomarker ratio was linearly inversely associated with the intake of total polyphenols (β = -0.11, P=0.040). When other inflammation biomarkers were considered, the serum IL-10 concentration was inversely associated with total polyphenol (β = -0.12, P=0.017) and flavonoid (β = -0.12, P=0.013) intakes, findings that were inconsistent with the biomarker ratio results. However, the anti-inflammatory capacity of polyphenols was confirmed by positive associations of IL-4 with phenolic acid (β = 0.09 P=0.049) and stilbene (β = 0.13, P=0.019) intakes and the negative association of IL-1, IL-2, and IFN-γ with lignan intake (β = -0.10, P=0.034; β = -0.09, P=0.049; β = -0.11, P=0.023). The negative relation with the overall pro/anti-inflammatory biomarker ratio suggests a potential anti-inflammatory role of high polyphenol intakes among European adolescents. Nevertheless, associations are dependent on polyphenol type and the inflammatory biomarker measured.

Relative validation of the adapted Mediterranean Diet Score for Adolescents by comparison with nutritional biomarkers and nutrient and food intakes: the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study.

To investigate whether adherence to the adapted Mediterranean Diet Score for Adolescents (MDS_A) and the adapted Mediterranean Diet Quality Index for Adolescents (KIDMED_A) is associated with better food/nutrient intakes and nutritional biomarkers. The Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study is a cross-sectional study aiming to obtain comparable data on a variety of nutritional and health-related parameters in European adolescents aged 12·5-17·5 years. Nine European countries. European adolescents (n 2330) recruited to the HELENA study. Dietary intake was obtained with 24 h dietary recalls, an FFQ and a Food Choices and Preferences questionnaire. MDS_A was calculated as a categorical variable using cut-offs (MDS_A), as a continuous variable (zMDS_A) and with energy adjustments (zEnMDS_A). The KIDMED_A score was also calculated. Multilevel linear regression analysis showed positive associations for zMDS_A and KIDMED_A with serum levels of vitamin D, vitamin C, plasma folate, holo-transcobalamin, β-carotene and n-3 fatty acids, while negative associations were observed with trans-fatty acid serum levels. For categorical indices, blood biomarkers showed few significant results. zMDS_A and KIDMED_A showed positive associations with vegetables and fruits intake, and negative associations with energy-dense and low-nutritious foods. zMDS_A and KIDMED_A were positively associated with all macronutrients, vitamins and minerals (all P < 0·0001), except with monosaccharides and PUFA for KIDMED_A and cholesterol for both indices (P < 0·05). zMDS_A and KIDMED_A have shown the strongest associations with the dietary indicators and biomarkers that have been associated with the Mediterranean diet before, and are therefore considered the most appropriate and valid Mediterranean diet scores for European adolescents.

Gender influences physical activity changes during adolescence: The HELENA study

We compared differences in physical activity (PA) between pre/mid-pubertal and post-pubertal participants according to gender. The study included a total of 1842 healthy participants aged 12.5-17.4 years, who participated in the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study. Participants wore a uniaxial accelerometer (ActiGraph© GT1M, Pensacola, FL, USA) attached to their lower back for seven consecutive days to measure PA. Pubertal status was assessed by physical examination and the population was classified as pre/mid-pubertal (Tanner stages 1-3) or post-pubertal (Tanner stages 4-5). PA was compared between these groups according to gender during the whole week, on school-free days and on school days, before and after school, and during lessons and recesses. When comparing the pre/mid-pubertal group with the post-pubertal group, girls' total PA did not differ between groups. However, a slight difference was observed in boys, among whom PA on school-free days showed a difference of 17.6% between the pre/mid-pubertal group and the post-pubertal group (679 kcounts vs 564 kcounts, respectively; P=0.0007) and 20% (162 kcount vs 135 kcounts; P=0.006) for school recess. There was no difference among girls. A reduced level of PA in the post-pubertal groups was only observed in boys during non-organized times such as on school-free days and during school recesses, with a moderate impact on total PA.

Leptin and adiposity as mediators on the association between early puberty and several biomarkers in European adolescents: the HELENA Study.

Background Adolescents having early puberty (EP) are more likely to have obesity and increased cardiometabolic and inflammatory markers and atherosclerosis risk. We aimed to assess the indirect and mediated effects of leptin and adiposity on the relation between EP and cardiometabolic and inflammatory markers in European adolescents. Methods A sample of 511 adolescents with EP (12.5-17.5 years) from the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) cross-sectional study was studied. To assess whether leptin levels and adiposity mediate the relation between EP and several biomarkers, linear regression models for mediation analyses were performed. Results EP was positively associated with the atherogenic index (Ath-I) (β=0.174; 95%CI 0.029-0.265) and negatively associated with the C-reactive protein (CRP) (β=-0.284; 95%CI -0.542 to -0.028) in girls. These associations were fully mediated by leptin levels (9.5%) and adiposity (44%), respectively. Moreover, EP has indirect effects on the apolipoprotein A-1 (ApoA-1) levels through adiposity in girls (for body mass index [BMI], β=0.014; 95%CI 0.005-0.028, and for waist circumference [WC], β=0.011; 95%CI 0.003-0.024), and on ApoA-1 (β=0.012; 95%CI 0.004-0.025), apolipoprotein B (ApoB) (β=-0.004; 95%CI -0.011 to -0.0004) and CRP (β=-0.265; 95%CI -0.819 to -0.047) through abdominal fat in boys. Conclusions Leptin levels and adiposity seem to play an important indirect and mediation role in the association between EP and cardiometabolic and inflammatory markers in adolescents. Weight control should be recommended in order to control the impaired cardiometabolic and inflammatory status arising in early pubertal adolescents.

Correlates of ideal cardiovascular health in European adolescents: The HELENA study

Background and aimsThe ideal cardiovascular health (iCVH) construct consists of 4 health behaviors (smoking status, body mass index, physical activity and diet) and 3 health factors (total cholesterol, blood pressure and fasting glucose). A greater number of iCVH components in adolescence are related to better cardiovascular health, but little is known about the correlates of iCVH in adolescents. Thus, the aim of the study was to examine correlates of iCVH in European adolescents. Methods and resultsThe study comprised 637 European adolescents with complete iCVH data. Participants were part of the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study, a cross-sectional, multicenter study conducted in 9 different European countries. Correlates investigated were sex and age, family affluence scale, maternal education, geographic location, sleep time, television viewing, duration of pregnancy, birth weight and breastfeeding. Younger adolescents, those whose mothers had medium/high education or those who watched television less than 2 h per day had a greater number of iCVH components compared to those who were older, had a mother with low education or watched television 2 h or more daily (P ≤ 0.01). ConclusionSince in our study older adolescents had worse iCVH than younger adolescents, early promotion of cardiovascular health may be important. Future studies may also investigate the usefulness of limiting television viewing to promote iCVH. Finally, since adolescents of mothers with low education had poorer iCVH, it may be of special interest to tailor public health promotion to adolescents from families with low socioeconomic status.

Prevalence of ideal cardiovascular health in European adolescents: The HELENA study

BackgroundThe ideal cardiovascular health (iCVH) construct consists of 4 health behaviours and 3 health factors and is strongly related to later cardiovascular disease. However, the prevalence of iCVH in European adolescents is currently unknown. MethodsThe Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study is a cross-sectional, multicentre study conducted in 9 European countries during 2006–2007 and included 3528 adolescents (1683 boys and 1845 girls) between 12.5 and 17.5years of age. Status (ideal vs. non-ideal) for the health behaviours (smoking status, body mass index, physical activity and diet) and health factors (total cholesterol, blood pressure and fasting glucose) were determined. ResultsOverall, the prevalence of ideal health behaviours was low; non-smoking (60.9% ideal), body mass index (76.8%), physical activity (62.1%), and diet (1.7%). The prevalence of ideal health factors was; total cholesterol (65.8%), blood pressure (62.0%) and plasma glucose (88.8%). ConclusionsThe low prevalence of iCVH behaviours, especially diet and physical activity, identified in European adolescents is likely to influence later cardiovascular health which strongly motivates efforts to increase ideal health behaviours in this population.

Associations between insulin resistance and three B-vitamins in European adolescents: the HELENA study

To assess whether adolescents with high body mass index (BMI), or fat mass index (FMI), in combination with insulin resistance (assessed with the Homeostatic Model Assessment [HOMA] index), had also lower blood vitamin B6, folate and vitamin B12 concentrations. Six hundred and fifteen adolescents from the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study, with data on B-vitamins (both intakes and status), and BMI, FMI, HOMA, were selected. Intakes were assessed by two non-consecutive 24-h recalls. B-vitamins biomarkers were measured by chromatography and immunoassay. Analysis of covariance was applied to elucidate the differences in B-vitamins between combinations of groups defined according to the median of the z-scores of markers of body composition and insulin sensitivity. When considering energy intakes and education of the mother in the model, in females, vitamin B6intakes were higher in the high BMI/high HOMA group than in the high BMI-low HOMA group. Similarly, vitamin B6intakes were higher in the high FMI/high HOMA group than in the low FMI/low HOMA group. Plasma vitamin B12was significantly lower in males in the high FMI/high HOMA group than in the low FMI/low HOMA group, keeping also significant their trends throughout the groups, a fact that can be observed also for females (p < 0.05). Adolescents with combined higher adiposity and higher HOMA insulin sensitivity showed lower vitamin B12plasma concentrations. These differences do not seem to be explained by dietary vitamin B12intake.

Regular breakfast consumption is associated with higher blood vitamin status in adolescents: the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study.

The present study aimed to examine the association between different breakfast consumption patterns and vitamin intakes and blood vitamin concentrations in European adolescents. Breakfast consumption was assessed by a questionnaire. Vitamin intake was calculated from two 24 h recalls. Blood vitamin and total homocysteine (tHcy) concentrations were analysed from fasting blood samples. The European Commission-funded HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study. Participants were 1058 (52·8 % females) European adolescents (aged 12·5-17·5 years) from ten cities. Lower vitamin D and vitamin C concentrations were observed in male and female breakfast skippers than in consumers (P<0·05). Female breakfast consumers presented higher holo-transcobalamin and lower tHcy (P<0·05), while males had higher cobalamin concentrations, compared with skippers (P<0·05). Higher vitamin D and total folate intakes were observed in adolescents who consumed breakfast compared with skippers (P<0·05). Likewise, female consumers had higher intakes of vitamin B6 and vitamin E than occasional consumers (P<0·05). Regular breakfast consumption is associated with higher blood vitamin D and cobalamin concentrations in males and with higher vitamin D and holo-transcobalamin and lower tHcy concentrations in females. Moreover, breakfast consumption is associated with high intakes of vitamin D and total folate in both sexes, and with high intakes of vitamin B6 and vitamin E in females.

Ideal cardiovascular health and inflammation in European adolescents: The HELENA study

Background and aimsInflammation plays a key role in atherosclerosis and this process seems to appear in childhood. The ideal cardiovascular health index (ICHI) has been inversely related to atherosclerotic plaque in adults. However, evidence regarding inflammation and ICHI in adolescents is scarce. The aim is to assess the association between ICHI and inflammation in European adolescents. Methods and resultsAs many as 543 adolescents (251 boys and 292 girls) from the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study, a cross-sectional multi-center study including 9 European countries, were measured. C-reactive protein (CRP), complement factors C3 and C4, leptin and white blood cell counts were used to compute an inflammatory score. Multilevel linear models and multilevel logistic regression were used to assess the association between ICHI and inflammation controlling by covariates. Higher ICHI was associated with a lower inflammatory score, as well as with several individual components, both in boys and girls (p < 0.01). In addition, adolescents with at least 4 ideal components of the ICHI had significantly lower inflammatory score and lower levels of the study biomarkers, except CRP. Finally, the multilevel logistic regression showed that for every unit increase in the ICHI, the probability of having an inflammatory profile decreased by 28.1% in girls. ConclusionResults from this study suggest that a better ICHI is associated with a lower inflammatory profile already in adolescence. Improving these health behaviors, and health factors included in the ICHI, could play an important role in CVD prevention.

Do adolescents accurately evaluate their diet quality? The HELENA study

The aim of this study was to assess the diet quality awareness and associated factors in a large sample of European adolescents. The study included 3389 healthy adolescents, aged 12.5-17.5 years, who participated in the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) Study. The adolescents' diet quality was based on repeated 24h recalls and scored into a Diet Quality Index for Adolescents (DQI-A) considering four components: meal, equilibrium, diversity and quality. A self-rated diet quality questionnaire was administered to adolescents to assess their dietary awareness. The association of DQI-A with dietary awareness was studied using a linear mixed model including the center as the random effect and dietary awareness as the fixed effect. There was a positive association between DQI-A scores and diet quality perception levels (p<0.0001). The mean DQI-A was 59.0 (SD=14.8) in adolescents with a low dietary awareness compared with 65.4 (SD=12.6) in adolescents with high dietary awareness (p<0.0001). Similar results were found for all the DQI components. When analyses were stratified, we found a significant heterogeneity across the nutritional status, with no significant association between DQI-A and dietary awareness level in obese adolescents, but a positive association in overweight, normal and undernourished groups. We found also a significant heterogeneity associated with the lunch location (school or home). No other factor affected dietary awareness (gender, pubertal status and maternal educational level). European adolescents evaluate well their food quality whatever their pubertal status, gender and parental educational level, except for the obese who are not able to assess their diet quality. Improving the dietary awareness in obese adolescents might help to induce behavioral changes.

Consumption of dairy products in youth, does it protect from cardio-metabolic risk?

Introduction: The high prevalence of obesity in children and adolescents is considered as a major global health concern and involves the onset of other comorbidities such as hypertension, dyslipidemia, chronic infl ammation and hyperinsulinemia, which are also considered as cardiovascular diseases risk factors. Several studies have observed that consumption of dairy products has a protective role on the development of cardiovascular diseases; however, the scientific evidence on this topic is very limited among children and adolescents. Objectives: To investigate the association between dairy products consumption and cardiovascular risk factors in young populations. Material and methods: The most up-to-date literature was reviewed, including some data from the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) study. A sample of adolescents (12.5-17.5 years) from 8 European cities was considered for the analysis. Results: US data showed a decrease in both number of servings and portion sizes of milk consumption. Within the HELENA study, dairy products emerged as the food group that better distinguished those adolescents at lower cardiovascular diseases risk. Among the HELENA adolescents, higher consumption of milk, yogurt and milk- and yogurt-based beverages was associated with lower body fat, lower risk for cardiovascular diseases, and higher cardiorespiratory fitness. Conclusions: More studies are needed to provide more evidence and to better understand the intrinsic mechanisms of the association between dairy products consumption, especially yogurt consumption, and obesity, diabetes, and other cardiovascular diseases risk factors.

Nutrition and Lifestyle in European Adolescents: The HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study

Adolescence is a critical period, because major physical and psychologic changes occur during a very short period of time. Changes in dietary habits may induce different types of nutritional disorders and are likely to track into adulthood. The aim of this review is to describe the key findings related to nutritional status in European adolescents participating in the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) study. We performed a cross-sectional study in 3528 (1845 females) adolescents aged 12.5–17.5 y. Birth weight was negatively associated with abdominal fat mass in adolescents and serum leptin concentrations (in female adolescents), providing additional evidence for a programming effect of birth weight on energy homeostasis control. Breakfast consumption was associated with lower body fat content and healthier cardiovascular profile. 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 more meat and meat products, fats, and sweets than recommended. For beverage consumption, sugar-sweetened beverages, sweetened milk, low-fat milk, and fruit juice provided the highest amount of energy. Although the intakes of saturated fatty acids (FAs) and salt were high, the intake of polyunsaturated FAs was low. Adolescents spent, on average, 9 h/d of their waking time (66–71% and 70–73% of the registered time in boys and girls, respectively) in sedentary activities. Factors associated with adolescents' sedentary behavior included the following: 1) age; 2) media availability in the bedroom; 3) sleeping time; 4) breakfast consumption; and 5) season. Sedentary time was also associated with cardiovascular risk factors and bone mineral content. In European adolescents, deficient concentrations were identified for plasma folate (15%), vitamin D (15%), pyridoxal 5′-phosphate (5%), β-carotene (25%), and vitamin E (5%). Scientists and public health authorities should raise awareness of the importance of a healthy and sustainable lifestyle as a foundation of the health of the European population, now and in the future.

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

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. 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. 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. 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.

Influence of parental socio-economic status on diet quality of European adolescents: results from the HELENA study

Diet quality is influenced by socio-economic and geographical factors. The present study sought to assess whether adolescents' diet quality is affected by their parents' socio-economic status and whether the relationship between these factors is similar in northern and southern Europe. Data collected in the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study in eight European countries were analysed. Dietary intake data were recorded via repeated 24 h recalls (using specifically developed HELENA Dietary Intake Assessment Tool software) and converted into an adolescent-specific Diet Quality Index (DQI-AM). Socio-economic status was estimated through parental educational level (Par-Educ-Lev) and parental occupation level (Par-Occ-Lev) as reported by the adolescents in a specific questionnaire. The DQI-AM data were then analysed as a function of Par-Educ-Lev and Par-Occ-Lev in northern European countries (Austria, Belgium, France, Germany and Sweden) and southern European countries (Greece, Italy and Spain). We studied a total of 1768 adolescents (age 14.7 (SD 1.3) years; percentage of girls: 52.8%; 1135 and 633 subjects from northern and southern Europe, respectively). On average, the DQI-AM score was higher in southern Europe than in northern Europe (69.1 (SD 0.1) v. 60.4 (SD 2.8), respectively; P < 0.001; Δ = 12.6%). The DQI was positively correlated with both paternal and maternal Par-Educ-Lev. However, this association was more pronounced in northern Europe than in southern Europe (P interaction = 0.004 for the mother and 0.06 for the father). The DQI was also positively correlated with Par-Occ-Lev (all P trends < 0.01), but this correlation was independent of the geographical area (P interaction = 0.51 for the mother and 0.50 for the father). In conclusion, Par-Educ-Lev and Par-Occ-Lev are associated with diet quality in adolescents in Europe. However, this association differs between northern Europe and southern Europe.

Sleep time and cardiovascular risk factors in adolescents: The HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) study

ObjectiveWe aimed to examine the association between adolescents’ sleep time and a cardiometabolic risk score. A second aim was to examine associations between sleep time and individual cardiometabolic risk factors. MethodsAdolescents (N=699; ages, 12.5–17.5years) participating in the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) study were examined. Sleep time was reported by a questionnaire. Physical activity (PA) was assessed by accelerometry (n=497). Cardiometabolic risk factors measurements included insulin resistance, blood pressure, adiposity markers, cardiorespiratory fitness, and blood lipids. A cardiovascular disease risk score was computed. Associations were examined by a multilevel regression analysis (linear for individual risk factors and Poisson for the clustered risk score). ResultsFor school days no association was found between sleep time and cardiometabolic risk factors. At weekend days, the prevalence ratio (PR) of having a clustered risk score increased by 15% for each additional hour of sleep controlling for age, sex, and socioeconomic status (SES); however, the prevalence disappeared when adjusting for PA. ConclusionsIn European adolescents sleep time is not associated with cardiometabolic risk factors when important confounders are considered. Future research about sleep cardiovascular risk factors should register other sleep dimensions (sleep patterns or disturbances) to provide a better insight in this scientific field.