Dishwashers are not only a wonderful timesaving luxury, but they also give us the reassurance that our dishes are exceptionally clean. A new study revealed that there could be a downside to dishwashers making dishes “too clean”; the study found that hand washing dishes instead could lower your children’s risk of developing allergic conditions like asthma or eczema.

Researchers at Queen Silvia Children’s Hospital in Sweden quizzed parents of approximately 1,000 Swedish children, all 7 or 8 years old, about the children’s history of asthma, eczema and seasonal allergies. 12% of the families in the study hand washed dishes, and the children in those families had nearly half the risk of developing allergic conditions in comparison to children in families that used a dishwasher.

Hand washing dishes exposes children to more bacteria, which could actually be beneficial in strengthening their immune system, and could be the reason why they have a reduced risk of developing an allergic condition.