Researchers found that children exposed to foods such as cereals, egg and fish at a young age were less likely to develop conditions such as asthma, eczema and allergic rhinitis later in childhood.
A team from the University of Tampere in Finland analysed data from 3,781 children, including timing of dietary exposure and assessments of asthma, allergic rhinitis and atopic eczema.
On average, children were exclusively breastfed for an average of 1.4 months. Total breastfeeding lasted on average for seven months.
Researchers found that total breastfeeding under 9.5 months was linked to an increased risk of non-atopic asthma.
By contrast, the risk of asthma and allergic rhinitis was lower among children exposed to wheat, rye, oats or barley at five to 5.5 months. The risk of atopic asthma was also lower if children were introduced to other cereals at less than 4.5 months.
The researchers also found that introduction to egg after 11 months or less was linked to reduced risk of asthma, allergic rhinitis and atopic sensitisation. Likewise, exposure to fish at nine months or less was linked to lower rates of allergic rhinitis and atopic sensitisation.
They concluded that early introduction to these foods appeared to decrease the risk of several major allergic diseases. The study authors also said children who were breastfed for longer were more protected against non-atopic asthma, but not atopic asthma. They believe this shows breastfeeding may affect different types of asthma.
Virtanen SM, Kaila M, Pekkanen J et al. J Allergy Clin Immunol Online 2012.