Folate, vitamin B₆, and vitamin B₁₂ status in European adolescents : associations with homocysteine as well as communicable and non-communicable factors

Adolescence implies important psychological, social, and physiological changes. Apart from the first year of life, both energy and nutrient requirements are greatest during adolescence. To ensure physiological growth during this critical period, an adequate intake of folate, vitamin B6, and vitamin B12 is mandatory. These B-vitamins are closely connected with homocysteine a well-known risk factor for cardiovascular diseases. In adolescents, a change towards an increasing consumption of energy dense but nutrient poor food is observed. Simultaneously, detrimental factors e.g. a sedentary lifestyle are implemented. Blood B vitamin and homocysteine reference values for adolescents do not exist. Therefore, the assessment of B-vitamin and homocysteine concentrations is not yet possible, but still needed. A prerequisite for the development of reference values is to record the present situation and to elucidate the influencing factors of B-vitamin status and homocysteine concentrations. Underlying data were taken from the HELENA study (“Healthy Lifestyle in Europe by Nutrition in Adolescence”). Overall, the present work elucidated several associations and provided potential reference data that might be a starting point for the further development of sound reference values. The relation of folate, vitamin B6, vitamin B12 status and homocysteine levels with selected non-communicable factors gender, age, sexual maturity, and the methylenetetrahydrofolate reductase 677C/T as well as selected communicable factors body composition, supplement use, and smoking were investigated. Cobalamin and homocysteine levels varied between genders. Higher age was related with increased homocysteine concentrations. Sexual maturity was inversely associated with folate, red blood cell folate, and holo-transcobalamin concentrations. Analogue to age, homocysteine concentrations were positively associated with sexual maturity. The methylenetetrahydrofolate reductase 677C/T polymorphism was associated with folate, red blood cell folate, cobalamin, holo transcobalamin, and homocysteine concentrations. Normal weight adolescents displayed higher folate and cobalamin concentrations than overweight adolescents. Supplement users had higher folate, red blood cell folate, and cobalamin concentrations compared with non-users and homocysteine concentrations were lower in supplement users than in non-users. Smoking was associated with lower folate, red blood cell folate, cobalamin, and pyridoxal-5-phosphate concentrations. Furthermore, homocysteine and its association with the communicable factors physical activity, cardiovascular fitness, and fatness was examined. Few studies have targeted this relationship sofar. Subjects were mostly adults and studies on adolescents display inconsistent results. In the present study homocysteine concentrations were not significantly associated with physical activity, cardiovascular fitness, or fatness after controlling for potential confounders, neither in males nor females. Based on observing patients with homocystinuria suffering also from premature osteoporosis and fractures, it is hypothesised that also folate, vitamin B6, and vitamin B12 status as well as homocysteine levels are associated with bone mineral density. However, in adolescents variations in bone mineral content and -density could not be explained by folate, vitamin B6, vitamin B12 status, and homocysteine levels.Folat, Vitamin B6- und Vitamin B12-Status Europäischer Jugendlicher – Assoziationen mit Homozystein, kommunizierbaren und nicht-kommunizierbaren Faktoren Die Adoleszenz beinhaltet wichtige psychologische, soziale und physiologische Veränderungen. Abgesehen vom ersten Lebensjahr ist der Energie- und Nährstoffbedarf am höchsten in der Adoleszenz. Um physiologisches Wachstum in dieser kritischen Zeit zu gewährleisten, ist eine adäquate Aufnahme von Folat, Vitamin B6 und Vitamin B12 zwingend erforderlich. Diese B-Vitamine sind eng mit Homozystein, einem Risikofaktor für Herz-Kreislauf-Krankheiten verbunden. Bei Jugendlichen wurde ein steigender Verzehr von energiedichten, aber nährstoffarmen Lebensmitteln beobachtet. Gleichzeitig werden nachteilige Faktoren wie z.B. ein bewegungsarmer Lebensstil übernommen. Für Jugendliche existieren bislang keine Referenzwerte für die oben genannten B-Vitamine und Homozystein, die im Blut gemessen werden. Daher ist eine Bewertung kaum möglich. Voraussetzung für die Entwicklung von verlässlichen Referenzwerten ist erstens die Beschreibung von aktuellen Daten und zweitens die Aufklärung, inwiefern diese Substrate mit möglichen beeinflussenden Faktoren zusammenhängen. Die untersuchten Daten der vorliegenden Arbeit stammen aus der HELENA Studie (“Healthy Lifestyle in Europe by Nutrition in Adolescence”). Insgesamt untersuchte die vorliegende Arbeit verschiedene Assoziationen und stellte potentielle Referenzdaten bereit, die als Ausgangspunkt für die weitere Entwicklung von verlässlichen Referenzwerten dienen könnten. Die Assoziationen zwischen dem Folat-, Vitamin B6- und Vitamin B12-Status sowie Homozysteinkonzentrationen und ausgewählten nicht-kommunizierbaren Faktoren wie Geschlecht, Alter, sexuelle Reife und dem Polymorphismus der Methylentetrahydrofolate Reduktase 677C/T und kommunizierbaren Faktoren wie Körperzusammensetzung, Gebrauch von Supplementen und Rauchverhalten wurden analysiert. Dabei zeigte sich, dass die Cobalamin- und Homozysteinkonzentrationen nach Geschlecht variierten. Ein höheres Alter war mit höheren Homozysteinkonzentrationen und vorangeschrittenere sexuelle Reife war mit niedrigeren Folat-, Erythrozytenfolat- und Holo-Transcobalaminkonzentrationen assoziiert. Analog zum Alter stieg Homozystein proportional mit dem sexuellen Reifegrad. Der Polymorphismus der Methylentetrahydrofolate Reduktase 677C/T war mit Folat-, Erythrozytenfolat-, Cobalamin-, Holo-Transcobalamin und Homozysteinkonzentrationen assoziiert. Normalgewichtige zeigten höhere Folat- und Cobalaminkonzentrationen als übergewichtige Jugendliche. Nutzer von Supplementen wiesen höhere Folat-, Erythrozytenfolat- und Cobalaminkonzentrationen und niedrigere Homozysteinkonzentrationen auf als Nichtnutzer. Rauchen war mit niedrigeren Folat-, Erythrozytenfolat-, Cobalamin- und Pyridoxal-5-phosphatkonzentrationen assoziiert. Des Weiteren wurde der Zusammenhang zwischen Homozystein und den kommunizierbaren Faktoren körperliche Aktivität, kardiovaskuläre Fitness und Fettleibigkeit untersucht. Wenige Studien evaluierten dieses Thema und diese konzentrierten sich meist auf Erwachsene. Studien mit Jugendlichen zeigten uneinheitliche Ergebnisse. In dieser Arbeit war Homozystein weder bei männlichen, noch bei weiblichen Teilnehmern signifikant mit körperlicher Aktivität, kardiovaskulärer Fitness oder Fettleibigkeit assoziiert. Basierend auf Beobachtungen von Homozystinurie-Patienten, die in jungen Jahren unter anderem an Osteoporose und Frakturen litten, wurde die Hypothese aufgestellt, dass der Folat- und Vitamin B12-Status, sowie Homozysteinkonzentrationen mit der Knochenmineraldichte assoziiert sein könnten. Bei Jugendlichen standen unterschiedliche Werte des Knochenmineralgehalts oder der dichte nicht mit dem Folat-, Vitamin B6- und Vitamin B12-Status, sowie Homozysteinkonzentrationen in Verbindung

Dietary patterns and their relationship with the perceptions of healthy eating in European adolescents : the HELENA study

Objective: The aim of this study was to identify dietary patterns (DPs) in European adolescents and to examine the association between perceptions of healthy eating and the obtained DPs. Method: A multinational cross-sectional study was carried out in adolescents aged 12.5 to 17.5?years and 2,027 (44.9% males) were considered for analysis. A self-reported questionnaire with information on food choices and preferences, including perceptions of healthy eating, and two 24-hour dietary recalls were used. Principal component analysis was used to obtain sex-specific DPs, and linear analyses of covariance were used to compare DPs according to perceptions of healthy eating. Results: Three and four DPs for boys and girls were obtained. In boys and girls, there were significant associations between some perceptions about healthy food and the Breakfast-DP (p?<?0.05). In boys, Breakfast-DP and Healthy Beverage-DP were associated with the perception of the own diet as healthy (p?<?0.05). Healthy Beverage-DP was associated with those disliking fruits and vegetables (p?<?0.05). Girls considering the own diet as healthy were associated with Mediterranean-DP, Breakfast-DP, and Unhealthy Beverage and Meat-DP (p?<?0.05). The perception of snacking as a necessary part of a healthy diet was associated with Breakfast-DP in both genders (p?<?0.05). Conclusions: In European adolescents, perceptions of healthy eating were mainly associated with a DP characterized by foods consumed at breakfast. Future studies should further explore these findings in order to implement health promotion programs to improve healthy eating habits in adolescents

Diet as a moderator in the association of sedentary behaviors with inflammatory biomarkers among adolescents in the HELENA study

AIM: To assess if a healthy diet might attenuate the positive sedentary-inflammation relation, whereas an unhealthy diet may increase the effect of sedentary behaviors on inflammatory biomarkers. METHODS: In 618 adolescents (13-17 years) of the European HELENA study, data were available on body composition, a set of inflammation markers, and food intake assessed by a self-administered computerized 24 h dietary recall for 2 days. A 9-point Mediterranean diet score and an antioxidant-rich diet z-score were used as dietary indices and tested as moderators. A set of low-grade inflammatory characteristics was used as outcome: several cytokines in an inflammatory ratio (IL-6, IL-10, TNF-α, TGFβ-1), C-reactive protein, three cell-adhesion molecules (sVCAM-1, sICAM-1, sE-selectin), three cardiovascular risk markers (GGT, ALT, homocysteine) and three immune cell types (white blood cells, lymphocytes, CD3). Sedentary behaviors were self-reported and analyzed as total screen time. Multiple linear regression analyses tested moderation by diet in the sedentary behaviors-inflammation association adjusted for age, sex, country, adiposity (sum of six skinfolds), parental education, and socio-economic status. RESULTS: Both diet scores, Mediterranean and antioxidant-rich diet, were significant protective moderators in the effect of sedentary behaviors on alanine-transaminase enzyme (P = 0.014; P = 0.027), and on the pro/anti-inflammatory cytokine ratio (P = 0.001; P = 0.004), but not on other inflammatory parameters. CONCLUSION: A higher adherence to the Mediterranean diet or an antioxidant-rich diet may attenuate the onset of oxidative stress signs associated by sedentary behaviors, whereas a poor diet seems to increase inflammation

Do dietary patterns determine levels of vitamin B6, folate, and vitamin B12 intake and corresponding biomarkers in European adolescents? The Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study

OBJECTIVES: To determine dietary patterns (DPs) and explain the highest variance of vitamin B6, folate, and B12 intake and related concentrations among European adolescents. METHODS: A total of 2173 adolescents who participated in the Healthy Lifestyle in Europe by Nutrition in Adolescence study met the eligibility criteria for the vitamin B intake analysis (46% boys) and 586 adolescents for the biomarkers analysis (47% boys). Two non-consecutive, 24-h, dietary recalls were used to assess the mean intakes. Concentrations were measured by chromatography and immunoassay testing. A reduced rank regression was applied to elucidate the combined effect of food intake of vitamin B and related concentrations. RESULTS: The identified DPs (one per vitamin B intake and biomarker and by sex) explained a variability between 34.2% and 23.7% of the vitamin B intake and between 17.2% and 7% of the biomarkers. In the reduced rank regression models, fish, eggs, cheese, whole milk and buttermilk intakes were loaded positively for vitamin B intake in both sexes; however, soft drinks and chocolate were loaded negatively. For the biomarkers, a higher variability was observed in the patterns in terms of food loads such as alcoholic drinks, sugars, and soft drinks. Some food items were loaded differently between intakes and biomarkers such as fish products, which was loaded positively for intakes but negatively for plasma folate in girls. CONCLUSIONS: The identified DPs explained up to 34.2% and 17.2% of the variability of the vitamin B intake and plasma concentrations, respectively, in European adolescents. Further studies are needed to elucidate the factors that determine such patterns