Posted by: Maria/MD Health Forum.com Team
Much research has been made to determine the influence of environmental factors in the development of various health problems. Allergy is one of the health conditions in which environmental factors are known to play a significant part. Exposure to allergens in early life, is thought to increase one’s risk for allergy. A Finnish study published in the Journal of Epidemiology and Community Health links the risk of developing food allergies to the season when the baby enters the early phase of gestation.
High pollen concentration makes many people suffer from allergy symptoms during springtime. It seems that the effects of pollen is not limited to those who go out to admire the great outdoors at that time of the year. The result of the population-based cohort study lead by Dr. Kaisa Pyrhönen of Institute of Health Sciences at the University of Oulu shows that babies who completed their first three months of life in the womb during springtime are more likely to develop food allergy.
Previous research has already shown that babies born in autumn or winter are more prone to eczema and wheeze, and have higher levels of circulating antibodies to allergen than children born in spring or summer. One theory suggests that antibodies begin to develop at around the 11th week of gestation. Increased exposure to allergens around this time could perhaps affect the immune system’s development, making children more susceptible to allergies later on. To find out whether the season of the early phase of gestation influences sensitization to food allergens in children, with particular reference to mothers’ pollen exposure in spring, Pyrhönen’s team studied 5920 children from South Karelia Finland who were born between 2001 and 2006.
For the study, questionnaires were sent to the parents. They were asked about duration of pregnancy, history of hay fever, and other possible risk factors. Among the participants, only 961 were tested for food allergies from birth to 4 years. Data shows that the incidence of positive food allergy test was highest among children born in October–November (10%), and lowest among those born in June–July (5%).
The researchers found out that food allergy was highest among children who entered their 11th gestational week in April–May (11%), the months in which the concentrations of birch and alder pollen were at their peak. Food sensitization was lowest among the children who were at the same stage of fetal development in December–January (6%).
In terms of specific food allergens, the results show that the risk of being sensitive to milk and eggs was three times higher in babies who reached their 11th week of fetal development around April and May than those who were in that stage in November or December.
The findings coincide with previous research about higher rates of allergies among children born in autumn and winter, however, the authors recognize that these are not enough to establish the connection between the increased pollen concentration and food allergies. While their study yielded interesting results, the authors cannot make new recommendations such as ways to reduce the risk of food allergies in children.
References:
Pyrhönen K, Läärä E, Hiltunen L, Kaila M, Hugg T, Näyhä S. Season of first trimester of pregnancy predicts sensitisation to food allergens in childhood: a population based cohort study from Finland Online First J Epidemiol Community Health 2010; doi 10.1136/jech.2009.105411
http://www.walesonline.co.uk/news/health-news/2010/10/20/children-more-likely-to-get-food-allergy-if-conceived-in-spring-91466-27506530/#ixzz13DDpqknR
http://www.hallinto.oulu.fi/viestin/tiedote/2010/varhaisraskaus.html
http://www.nhs.uk/news/2010/10October/Pages/child-allergy-may-be-influenced-in-womb.aspx
Photo credit: Ari Laakso
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Tags: firts trimester, food allergy, pollen, Pregnancy, season
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