Karin Jonsson

No association between allergy and current 25-hydroxy vitamin D in serum or vitamin D intake

Vitamin D may be involved in allergy development, but there is conflicting evidence. We investigated if dietary intake of vitamin D and levels of 25OHD in serum differed between allergic and nonallergic adolescents and if serum 25OHD correlated with dietary intake of vitamin D or season of blood sampling.

Fat intake and breast milk fatty acid composition in farming and nonfarming women and allergy development in the offspring.

Background:Children growing up on small family farms are at much lower risk of developing allergy than other children. We hypothesized that low intake of margarine and polyunsaturated fats among farming families could contribute to this protection.Methods:Twenty-eight mother–infant pairs living on small dairy farms and 37 nonfarm rural resident pairs were recruited in the FARMFLORA birth cohort. Food items expected to affect dietary fat composition were recorded by food frequency questionnaires during pregnancy and by 24-h recalls followed by 24-h food diaries during lactation. Allergy was diagnosed by doctors, using strict predefined criteria. Maternal diet and breast milk fat composition were compared between farming and nonfarming mothers and related to children’s allergy at age 3 y.Results:Farming mothers consumed more butter, whole milk, saturated fat, and total fat than nonfarming mothers, who consumed more margarine, oils, and low-fat milk. Farming mothers’ breast milk contained higher proportions of saturated and lower proportions of polyunsaturated fat. Allergy was eight times more common in nonfarm children. Mothers of allergic children consumed more margarine and oils than mothers of nonallergic children.Conclusion:Low maternal consumption of margarine and vegetable oils might contribute to the allergy-preventive effect of growing up on small dairy farms.

Serum fatty acid profile does not reflect seafood intake in adolescents with atopic eczema

Long‐chain polyunsaturated fatty acids (LCPUFAs) are immunomodulatory, but their role in allergy development is controversial. We investigated whether proportions of LCPUFAs in serum phospholipids were related to allergic diagnosis, seafood intake and LCPUFA proportions in cord blood.

Serum fatty acids in infants, reflecting family fish consumption, were inversely associated with allergy development but not related to farm residence.

In this study, differences in serum fatty acid patterns between farm and nonfarm infants were investigated and related to subsequent allergy development. We also related allergy‐related serum fatty acids to maternal diet and breast milk fatty acids.

Diet in 1-year-old farm and control children and allergy development: results from the FARMFLORA birth cohort

Background A farming environment confers strong protection against allergy development. We have previously shown that farming mothers consume more full-fat dairy than control mothers, who instead consume more low-fat dairy, margarine, and oils; margarine and oil intake was associated with increased risk of allergy development in their children. Objectives The aims of this study were to investigate the differences in diet between children in farming and control families at 1 year of age, to investigate the relation between the diets of the mothers and their children, and to relate the childrens diet to allergy development. Design The diet of 1-year-old children from dairy farming families (n=28) and from control families in the same rural area (n=37) was assessed by 24-h dietary recalls, followed by 24-h food diaries. Allergy was diagnosed by pediatricians at 3 years of age using strict predefined criteria. Results Farm children had a higher intake of farm milk, whole cream, cholesterol, saturated fat, and fat in total and tended to eat more butter, while controls consumed more carbohydrates and poultry and tended to eat more margarine. Farm children also had higher intakes of homemade porridge/gruel, oily fish, and iodine. The intake of butter and whole milk in children and mothers correlated significantly in farm families but not in controls. A weak negative association was found between seafood intake and allergy development, while allergy was positively associated with the intake of pork as well as zinc in the control group; these intakes also correlated with each other. Conclusions Consistent with mothers in farming families, the children consumed more full-fat dairy and saturated fat than did controls, but this could not be linked to the low risk of allergy in the farming group. Seafood intake might protect against allergy development, in accordance with earlier findings.

Late introduction of fish and eggs is associated with increased risk of allergy development – results from the FARMFLORA birth cohort

ABSTRACT The prevalence of allergy is markedly low in children growing up on farms. An increasing number of studies indicate that the timing of food introduction may affect allergy development. We aimed to investigate if protection against allergy in farm environments may be mediated through differences in food-introduction practices between farm and non-farm families, using an explorative approach. Twenty-eight farm and 37 non-farm children were included in the FARMFLORA birth cohort. Practices of breastfeeding and introduction of formulas and complementary foods were collected by questionnaires at 6, 12, and 18 months of age. Allergy was diagnosed by pediatricians at 3 years of age. The only difference in food-introduction practices observed between farm and non-farm children was an earlier introduction of nuts in farmers (median month: 11 [IQR: 8–6] in farmers, 15 [12–19] in non-farmers). One farm child (4%) and 10 non-farm children (27%) were allergic at 3 years of age. Lower risk of allergy development was associated with early exclusive breastfeeding (continuous variable; OR = 0.59, 95% CI: 0.39–0.89), but also having received eggs (OR = 0.08, 95% CI: 0.13–0.54) and fish (logistic regression not applicable, P = 0.01 in likelihood ratio testing [χ2]) at 10 months of age or earlier compared to later. Our results were not affected by reverse causation, as judged by a questionnaire sent to the families in retrospect. Timing of introduction of complementary foods is unlikely to contribute to the lower risk of allergy among farm children. Although early exclusive breastfeeding was associated with a lower rate of allergy development, postponed introduction of complementary foods might increase the risk of developing allergy. Owing to the limited sample size, our results are only indicative, but support prior findings.

Nutritional impact on Immunological maturation during Childhood in relation to the Environment (NICE): a prospective birth cohort in northern Sweden

Introduction Prenatal and neonatal environmental factors, such as nutrition, microbes and toxicants, may affect health throughout life. Many diseases, such as allergy and impaired child development, may be programmed already in utero or during early infancy. Birth cohorts are important tools to study associations between early life exposure and disease risk. Here, we describe the study protocol of the prospective birth cohort, ‘Nutritional impact on Immunological maturation during Childhood in relation to the Environment’ (NICE). The primary aim of the NICE cohort is to clarify the effect of key environmental exposures—diet, microbes and environmental toxicants—during pregnancy and early childhood, on the maturation of the infant’s immune system, including initiation of sensitisation and allergy as well as some secondary outcomes: infant growth, obesity, neurological development and oral health. Methods and analysis The NICE cohort will recruit about 650 families during mid-pregnancy. The principal inclusion criterion will be planned birth at the Sunderby Hospital in the north of Sweden, during 2015–2018. Questionnaires data and biological samples will be collected at 10 time-points, from pregnancy until the children reach 4 years of age. Samples will be collected primarily from mothers and children, and from fathers. Biological samples include blood, urine, placenta, breast milk, meconium, faeces, saliva and hair. Information regarding allergic heredity, diet, socioeconomic status, lifestyle including smoking, siblings, pet ownership, etc will be collected using questionnaires. Sensitisation to common allergens will be assessed by skin prick testing and allergic disease will be diagnosed by a paediatrician at 1 and 4 years of age. At 4 years of age, the children will also be examined regarding growth, neurobehavioural and neurophysiological status and oral health. Ethics and dissemination The NICE cohort has been approved by the Regional Ethical Review Board in Umeå, Sweden (2013/18-31M). Results will be disseminated through peer-reviewed journals and communicated on scientific conferences.