Intake of fruit and vegetables in European children and their mothers, folate intake in Swedish children and health indicators : Overweight, plasma homocysteine levels and school performance

Sammanfattning: An adequate fruit and vegetable intake provides essential nutrients and nutritive compounds and is considered an important part of a healthy lifestyle. Within the Pro Children project, an instrument for assessment of fruit and vegetable intake was developed, for use in nine European countries. This thesis describes the fruit and vegetable intake of 11 -year-old children and their mothers and looks at the prevalence of overweight and obesity in the group. From the European Youth Heart Study, the folate intake of 9- and 15-year old children and adolescents in Sweden is described. The thesis also investigates folate status and methylenetetrahydrofolate reductase (MTHFR) polymorphisms, and associations with school performance. Method and material: The subjects in the Pro Children cross-sectional study were 13,037 school children born in 1992 and 9,241 mothers from Austria, Belgium, Denmark, Iceland, the Netherlands, Norway, Portugal, Spain and Sweden. The survey was conducted in October/December 2003. Height and weight of the children from parent questionnaires were analyzed in relation to fruit and vegetable intake. Overweight and obesity rates were assessed using international cut-off levels. A 24-hour recall was used to assess folate intake of 1,137 children aged 9 or and 15, in Sweden during 1998/99. Genotyping of MTHFR polymorphisms was performed by pyrosequencing and homocysteine (tHcy) analyzed using an immunoassay. School grades were reported from schools. Results: Vegetable intake was lower than fruit intake, boys consumed less fruit and vegetables than girls did. The highest total fruit and vegetable intake for children was found in Austria and Portugal, the lowest in Spain and Iceland. For mothers, the highest fruit intake levels were seen in Portugal, Denmark and Sweden and the lowest in Iceland. A high vegetable intake was found in Portugal and Belgium, the lowest in Spain. The prevalence of overweight and obesity was highest in Portugal and Spain. No correlation was seen in fruit and vegetable intake versus BMI. For Swedish children, the MTHFR 677 TT genotype and folate intake were significant determinants of tHcy levels. Folate intake was positively and tHcy negatively correlated to school performance. Best sources of folate were milk and yoghurt. Discussion: The fruit and vegetable intake of 11 -year-old children and their mothers were below food-based dietary guidelines in all countries, although these guidelines were difficult to interpret. Prospective studies are needed to corroborate associations between fruit and vegetable intake and weight status. The vegetables chosen by children are only providing marginal amounts of folate. The results regarding school performance and folate intake highlights the importance of this area and need for more research. Conclusions: It is important to target mothers in order to influence children's fruit and vegetable intake. The importance of school meals for vegetable intake as well as milk/yoghurt intake, important sources for folate, is vital. Folate intake seems to be marginal in Swedish individuals with the genotype MTH17R 677 TT. The findings on school performance warrant further investigation. The adult and old age results from an early marginal folate status, in regard to cardiovascular health, fertility, birth defects and dementia need urgent attention.