Pregnant women satisfying cravings with sweets might be more likely to have a child with allergies or asthma, a new study suggests.

Researchers from Queen Mary University of London observed nearly nine thousand mothers who gave birth in the 1990s and their children. They compared moms who ate the least amount of free sugars (less than 7 teaspoons daily) to those who ate the most (16 to 69 teaspoons daily), and found children born to women in the high-sugar group were 73% more likely to be diagnosed with allergies to two or more allergens and 101% more likely to have allergic asthma.

Free sugars include added sugars and naturally present sugars (think: honey, syrups and fruit juice). Foods packed with the most free sugars include soda, jams, cakes, cookies and fruit juices. Sugars in whole fruits and vegetables are not free sugars.

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The study, which is published in the European Respiratory Journal, is observational, but the team speculates a high-sugar maternal diet triggers an ongoing postnatal allergic immune reaction, leading to allergic inflammation in the baby's developing lung. Annabelle Bedard, a postdoctoral fellow on the research team, pointed out in an email that fructose consumption (high fructose corn syrup) rose to 30% of per capita consumed refined sugars in the U.S. between 1970 and 2000.

"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," lead researcher professor Seif Shaheen said in a release. "However, given the extremely high consumption of sugar in the West, we will certainly be investigating this hypothesis further with some urgency."

Shaheen said if they are able to replicate their findings, researchers will design a trial to see if childhood allergies and allergic asthma can be reduced by decreasing sugar in mom's diet. Bedard said they are currently trying to study two other UK birth groups.

In the meantime, she recommends pregnant women follow current guidelines on sugar consumption. The American Heart Association advises women limit free sugars, which increase calories and hold no nutrients, to 6 teaspoons daily.

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