A new study suggests that the children of women who have a high intake of ‘free sugars’ during pregnancy are at increased risk of developing allergies or allergic asthma, independent of sugar intake in early childhood. The study analysed data from the Avon Longitudinal Study of Parents and Children (ALSPAC) which recruited more than 14,500 pregnant women resident in Avon, UK, between April 1991 and December 1992.
‘Free sugars’ are sugars added to foods or drinks by manufacturers, cooks or consumers, and sugars which are naturally present in honey, syrups and fruit juices. Studies have already shown that children with a high consumption of sugar-sweetened drinks and fruit juices have an increased risk of asthma, particularly ‘atopic’ or allergic asthma and this report suggests that sugar exposure during development in the womb can also increase this risk.
The reasons why a mother’s free sugar intake might lead to allergy and asthma in her children are not known, although the authors speculate that it might be fructose intake which is to blame. Fructose is a major component of added sugars (table sugar is sucrose, which comprises glucose plus fructose), is present naturally in fruit juice and is added to sweetened drinks. However, this sort of ‘observational’ study, no matter how large, does not tell us anything about how a mother’s diet during pregnancy might affect her children. More research is needed to help us fully understand.
Before people get too anxious, it’s important to note that there could be other factors which are important in determining asthma and allergy risk that the study did not account for. Importantly, the authors of the study do note that they need to confirm their results in other birth cohorts to be sure that this is a real finding. Other potential problems include that the mothers’ dietary intake was self-reported (which can be unreliable) and, as is usual with these studies, complete sets of data were not available for all mothers and children. Additionally, data were only available for children up to the age of 7 years, so we do not know whether any effects are long-lasting. However, this study adds to many others showing that diet during pregnancy may be important for offspring health.
The study was published in the European Respiratory Journal and a copy of the paper can be downloaded here.
The University of Edinburgh has a substantial programme of pregnancy research – if you’re interested in learning more there is a lot of information here on the University website. Tommy’s funds research into the causes and prevention of pregnancy complications that lead to miscarriage, stillbirth and premature birth and funds a Research Centre in Edinburgh – you can find more information about this here.
Photographs from freestocks.org and Gabby Orcutt on Unsplash.