Environmental factors associated with allergy in urban and rural children from the South African Food Allergy (SAFFA) cohort.
Aeroallergen
Africa
advanced glycation end-products
aeroallergen sensitization
allergic rhinitis
antibiotics
antihelminthics
asthma
atopic dermatitis
cesarean section
cooking fuel
delivery mode
eczema
environmental exposures
farm animals
fast foods
food allergy
food sensitization
heating fuel
pets
prebiotics
prevalence
probiotics
rural
smoking
sunlight
unpasteurized milk
urban
urbanization
Journal
The Journal of allergy and clinical immunology
ISSN: 1097-6825
Titre abrégé: J Allergy Clin Immunol
Pays: United States
ID NLM: 1275002
Informations de publication
Date de publication:
01 2020
01 2020
Historique:
received:
26
04
2019
revised:
21
06
2019
accepted:
02
07
2019
pubmed:
14
10
2019
medline:
28
7
2020
entrez:
14
10
2019
Statut:
ppublish
Résumé
The prevalence of allergic diseases differs in urban and rural populations. We sought to assess associations between environmental and dietary factors with allergic diseases in urban and rural South African children. Toddlers aged 12 to 36 months were assessed for food allergen and aeroallergen sensitization, atopic dermatitis, allergic rhinitis, asthma, and challenge-proved food allergy. Information was collected on family history of allergic diseases, household size, socioeconomic status, delivery mode, antibiotic and probiotic use, exposure to fermented and unpasteurized milk, antihelminth treatment, sunlight exposure, pet and farm animal exposure, cigarette smoke, and household cooking and heating fuels. Antenatal exposures to pets, livestock, and cigarette smoke were assessed. A subsection completed questions on consumption of fruits and vegetables, fast foods, soft drinks/fruit juices, and fried/microwaved meat. Risk and protective factors differed between urban and rural settings. Exposure to farm animals in infants and their mothers during pregnancy was protective against allergic outcomes in the rural population. Consumption of unpasteurized milk is uncommon in this group of rural children and is unlikely to be an important factor in rural protection. In urban children birth by cesarean section is associated with food allergy, and consumption of fermented milk products is associated with reduced asthma and atopic dermatitis. In both cohorts antenatal maternal smoking and environmental smoking exposure were predominantly associated with asthma, and consumption of fast foods and fried meats were associated with allergy. In this rural environment exposure to livestock is the strongest protective factor. In urban communities, where animal contact is rare, risk factors include cesarian section, and protective factors include consumption of fermented milk products. Modifiable risk factors urgently require interventions to prevent increasing allergy rates in countries undergoing rapid urbanization.
Sections du résumé
BACKGROUND
The prevalence of allergic diseases differs in urban and rural populations.
OBJECTIVE
We sought to assess associations between environmental and dietary factors with allergic diseases in urban and rural South African children.
METHODS
Toddlers aged 12 to 36 months were assessed for food allergen and aeroallergen sensitization, atopic dermatitis, allergic rhinitis, asthma, and challenge-proved food allergy. Information was collected on family history of allergic diseases, household size, socioeconomic status, delivery mode, antibiotic and probiotic use, exposure to fermented and unpasteurized milk, antihelminth treatment, sunlight exposure, pet and farm animal exposure, cigarette smoke, and household cooking and heating fuels. Antenatal exposures to pets, livestock, and cigarette smoke were assessed. A subsection completed questions on consumption of fruits and vegetables, fast foods, soft drinks/fruit juices, and fried/microwaved meat.
RESULTS
Risk and protective factors differed between urban and rural settings. Exposure to farm animals in infants and their mothers during pregnancy was protective against allergic outcomes in the rural population. Consumption of unpasteurized milk is uncommon in this group of rural children and is unlikely to be an important factor in rural protection. In urban children birth by cesarean section is associated with food allergy, and consumption of fermented milk products is associated with reduced asthma and atopic dermatitis. In both cohorts antenatal maternal smoking and environmental smoking exposure were predominantly associated with asthma, and consumption of fast foods and fried meats were associated with allergy.
CONCLUSION
In this rural environment exposure to livestock is the strongest protective factor. In urban communities, where animal contact is rare, risk factors include cesarian section, and protective factors include consumption of fermented milk products. Modifiable risk factors urgently require interventions to prevent increasing allergy rates in countries undergoing rapid urbanization.
Identifiants
pubmed: 31606483
pii: S0091-6749(19)31309-0
doi: 10.1016/j.jaci.2019.07.048
pii:
doi:
Types de publication
Clinical Trial
Journal Article
Multicenter Study
Research Support, Non-U.S. Gov't
Langues
eng
Sous-ensembles de citation
IM
Pagination
415-426Informations de copyright
Copyright © 2019 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.