Parents use a variety of methods to clean a baby’s pacifier: rising it in tap water, boiling it, or putting it in their own mouth and sucking on it before giving it back to the baby. According to a new study, parents who “clean” their child’s pacifier by sucking on it can also protect their infant from developing allergies.

The study, “Pacifier Cleaning Practices and Risk of Allergy Development,” in the June 2013 issue of Pediatrics (published online May 6), examined 184 infants at 18 and 36 months of age for clinical allergy symptoms and sensitization to food and airborne allergens. Researchers found that children whose parents sucked on their pacifiers to clean them had one-third the risk of developing eczema (the most common early manifestation of allergy), at 18 months of age, compared to children whose parents did not use this cleaning practice. Development of eczema up to 36 months of age was significantly lower in children whose parents sucked on their pacifiers during the first 6 months of life.

Additionally, infants who were vaginally delivered and experienced parental pacifier sucking also had a reduced incidence of eczema at 18 months of age. Study authors conclude that early exposure to parental saliva may help stimulate the baby’s immune system, resulting in a reduced risk of allergy development.