The effects of farming and birth order on asthma and allergies

Abstract

A farm childhood is apparently protective in allergic disease, but studies of this issue in Europe have been confined to particular types of farming practice. This study addressed whether or not this effect was generalisable.A cross-sectional survey of 800 schoolchildren living in rural Crete was undertaken. Standard questions relating to allergic disease were included and atopy was measured through skin-prick tests involving 10 local aeroallergens.The prevalence of atopy was 24%, but associated symptoms were far less common. At all ages, children from farming families had more frequent contact with farm animals (mainly goats), but were no less likely to be atopic. Atopy and seasonal rhinitis were significantly and independently more common among first-born children.This community has an intermediate prevalence of atopy but a very low frequency of allergic disease; farming does not seem to be an important determinant, possibly because it is of the wrong sort. Thus farming effects may be specific to local practices. First-born children in this community also appear to be at increased risk of allergic disease.

Asthma Symptoms and Airway Narrowing in Children Growing up in an Urban versus Rural Environment

“…In the rural areas of this study, inhabitants have little contact with large animals and thus constitute an entirely different rural milieu than the one reported by studies from central Europe (36,37).…”

Protective effect of fruits, vegetables and the Mediterranean diet on asthma and allergies among children in Crete

“…The outcome variables that were evaluated in relation to diet were: wheezing ever, wheezing ever with atopy, current wheezing, nocturnal dry cough in the last 12 months apart from a common cold/flu, allergic rhinitis ever, allergic rhinitis ever with atopy, current allergic rhinitis, current seasonal allergic rhinitis and atopy. Multivariate logistic regression models were performed to examine the association between fruit and vegetable consumption (in three levels, using ''never'' as reference) and the outcome variables, after adjusting for the following confounders: age (in years; three categories: 7-12, [13][14][15][16][17][18], sex, body mass index (BMI, age-and sex-adjusted cut off points for normal, overweight, obese children), 19 parental asthma (yes, no) and number of older siblings (0, 1, 2, 3+). Logistic regression was performed to examine the association between the outcome variables and the consumption of specific nutrients included in the Mediterranean diet index and, separately, with the overall adherence to the Mediterranean diet (in three levels, using ''low'' level as reference).…”

“…All school children aged between 7 and 18 years were invited to participate in the study (n = 857). 15 Permission was obtained from the appropriate ethical committees (Venizelion Hospital in Heraklion, Royal Brompton Hospital in London, Ministry of Education in Greece). All parents gave written informed consent.…”

“…In a cross-sectional study of children living in rural settings on the island, we found an ''intermediate'' prevalence of atopy but a low prevalence of allergic disease. 15 To test the hypothesis that dietary intake of fresh fruits and vegetables rich in antioxidants and adherence to the traditional Mediterranean diet prevent the occurrence of respiratory symptoms related to atopy, we examined nutritional information collected in the same cross-sectional survey.…”

In utero Programming of Allergic Susceptibility

“…Studies assessing birth order and subsequent allergy development reveal a clear protective benefit of siblings [24,25,26,27,28], supported by a meta-analysis of 53 studies, that showed that the odds of eczema, hayfever, asthma or sensitisation are reduced by 28-56% in children with ≥3 siblings [29]. …”