Lasting effects? Jamie Grill/Getty

Pregnant women who eat large amounts of sugar may be more likely to have children with allergies.

A study of 9,000 women found that those who ate high levels of sugar during pregnancy were around twice as likely to have a child that went on to develop allergic asthma than woman who ate relatively little sugar. Allergic asthma is the most common form of asthma, and involves allergens provoking the immune system into causing breathing problems.

“We cannot say on the basis of these observations that high intake of sugar by mothers in pregnancy is definitely causing allergy and allergic asthma in their offspring,” says Seif Shaheen, at Queen Mary, University of London, who led the study. “However, given the extremely high consumption of sugar in the West, we will certainly be investigating this hypothesis further with some urgency.”


One theory for how sugar could cause asthma is that large amounts of fructose might trigger an immune response in the body, leading to inflammation in the lungs. Fructose is a sugar found in fruit and corn syrup, and is used widely in processed food.

Many factors influence a baby’s allergy risk, including exposure to microbes and pollutants, and the type of milk they are fed, says Sheena Cruickshank, at the University of Manchester, UK. “Future studies should take these variables into account so we can understand the full relationship between maternal diet during pregnancy and allergic disease in offspring.”

Journal reference: European Respiratory Journal

Read more: Fat vs carbs: What’s really worse for your health?