Season of birth impacts on food allergy risk

A Finnish study has found the season of birth or season of the early phase of gestation is associated with greater sensitisation to food allergens in children. Almost ten per cent of babies born in autumn subsequently developed an allergic response compared to five per cent of babies born during summer months.

The study looked at nearly six thousand children born in one region of Finland between early 2001 and 2006, of which 961 had been tested for food allergies. Those born in October and November were found to be almost twice as likely to show a form of food intolerance by the age of four, than those born in June and July. These autumn babies were three times as likely to have an allergy to milk and eggs as summer babies.

The researchers attribute the increased allergy prevalence to pollen exposure when the foetus is at a critical time during pregnancy. The foetus is known to start producing antibodies around the end of the third month. Exposure to pollen at this stage seems to trigger the development of immunoglobulin E antibodies, which are known to be linked to food allergies. More research is required to understand the mechanism between pollen exposure and the development of immunoglobulin E, and why sensitivity appears to be greater to milk and eggs than other foods.

Reference:Pyrhönen et al. Journal of Epidemiology and Community Health. 2010. Vol. 59(4). DOI:10.1136/jech.2009.105411