Sugar intake during pregnancy associated with allergy in children

10 August 2017
Graphic showing a cup made of sugar

There appears to be a link between a mother’s sugar intake in pregnancy and a child’s risk of developing allergy and allergic asthma.

The finding is outlined in a study in the European Respiratory Journal which looked at the association between maternal intake of free sugars (or sugars added to foods and drinks) and allergy and asthma in children at seven years of age.  

The researchers examined data collected in the Avon Longitudinal Study of Parents and Children (ALSPAC).  They compared the 20% of mothers with the highest sugar intake and the 20% of mothers with the lowest sugar intake.

They found that children born to mothers with the highest sugar intake had:

  • A 38% increase risk of allergy
  • A 101% increase in risk for allergic asthma.

The researchers found no association with eczema or hay fever and there was only weak evidence for a link between free sugar intake in pregnancy and asthma overall.

Lead researchers, Queen Mary University of London’s Professor Seif Shaheen, says the association may be explained by a high maternal intake of fructose causing a persistent postnatal allergic immune response leading to allergic inflammation in the developing lung.

“We cannot say on the basis of these observations that a high intake of sugar by mothers in pregnancy is definitely causing allergy and allergic asthma in their offspring. However, given the extremely high consumption of sugar in the West, we will certainly be investigating this hypothesis further with some urgency.

“The first step is to see whether we can replicate these findings in a different cohort of mothers and children. If we can, then we will design a trial to test whether we can prevent childhood allergy and allergic asthma by reducing the consumption of sugar by mothers during pregnancy.

“In the meantime, we would recommend that pregnant women follow current guidelines and avoid excessive sugar consumption.”

Importantly, the offspring’s free sugar intake in early childhood was found to have no association with the outcomes seen in the analysis.

As the study is observational, it does not prove a causal link between maternal sugar intake and allergies or asthma. A randomised controlled trial would be needed to definitively test causality.

You can read the full study looking at the links between sugar intake in pregnancy and allergy and asthma in children here.