Food diversity in infancy and the risk of childhood asthma and allergies.
BACKGROUND
Recently, the bacterial diversity of the intestinal flora and the diversity of various environmental factors during infancy have been linked to the development of allergies in childhood. Food is an important environmental exposure, but the role of food diversity in the development of asthma and allergies in childhood is poorly defined.


OBJECTIVE
We studied the associations between food diversity during the first year of life and the development of asthma and allergies by age 5 years.


METHODS
In a Finnish birth cohort we analyzed data on 3142 consecutively born children. We studied food diversity at 3, 4, 6, and 12 months of age. Asthma, wheeze, atopic eczema, and allergic rhinitis were measured by using the International Study of Asthma and Allergies in Childhood questionnaire at age 5 years.


RESULTS
By 3 and 4 months of age, food diversity was not associated with any of the allergic end points. By 6 months of age, less food diversity was associated with increased risk of allergic rhinitis but not with the other end points. By 12 months of age, less food diversity was associated with increased risk of any asthma, atopic asthma, wheeze, and allergic rhinitis.


CONCLUSIONS
Less food diversity during the first year of life might increase the risk of asthma and allergies in childhood. The mechanisms for this association are unclear, but increased dietary antigen exposure might contribute to this link.
School of Health Sciences, University of Tampere, Tampere, Finland; Allergy & Respiratory Research Group, Center for Population Health Sciences, University of Edinburgh, Edinburgh, United Kingdom. Electronic address: bright.nwaru@uta.fi.
Bright I
BI
Nwaru
School of Health Sciences, University of Tampere, Tampere, Finland; Nutrition Unit, Department of Lifestyle and Participation, National Institute for Health and Welfare, Helsinki, Finland.
Hanna-Mari
HM
Takkinen
Department of Pediatrics, Tampere University Hospital, Tampere, Finland; Hjelt Institute, University of Helsinki, Helsinki, Finland.
Minna
M
Kaila
Division of Nutrition, Department of Food and Environmental Sciences, University of Helsinki, Helsinki, Finland.
Maijaliisa
M
Erkkola
School of Health Sciences, University of Tampere, Tampere, Finland; Science Center of Pirkanmaa Hospital District, Tampere, Finland.
Suvi
S
Ahonen
Environmental Epidemiology Unit, National Institute for Health and Welfare, Kuopio, Finland; Unit of Public Health and Clinical Nutrition, University of Eastern Finland, Kuopio, Finland.
Juha
J
Pekkanen
Department of Pediatrics, University of Turku, Turku, Finland.
Olli
O
Simell
Department of Pediatrics, Medical Research Center, Oulu University Hospital and University of Oulu, Oulu, Finland.
Riitta
R
Veijola
Immunogenetics Laboratory, University of Turku, Turku, Finland; Department of Clinical Microbiology, University of Eastern Finland, Kuopio, Finland.
Jorma
J
Ilonen
Medical School, University of Tampere, Tampere, Finland; Fimlab Laboratories, Tampere, Finland.
Heikki
H
Hyöty
Department of Pediatrics, Tampere University Hospital, Tampere, Finland; Folkhälsan Research Center, Helsinki, Finland; Children's Hospital, University of Helsinki, and Helsinki University Central Hospital, Helsinki, Finland; Diabetes and Obesity Research Program, University of Helsinki, Helsinki, Finland.
Mikael
M
Knip
School of Health Sciences, University of Tampere, Tampere, Finland; Nutrition Unit, Department of Lifestyle and Participation, National Institute for Health and Welfare, Helsinki, Finland; Department of Pediatrics, Tampere University Hospital, Tampere, Finland; Science Center of Pirkanmaa Hospital District, Tampere, Finland.
Suvi M
SM
Virtanen
D000367:Age Factors; D001249:Asthma / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology*; D004032:Diet; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology*; D007223:Infant; D007225:Infant Food; D007231:Infant, Newborn; D008297:Male; D012306:Risk
Asthma; allergic rhinitis; atopic eczema; children; food diversity; wheeze