Is our squeaky clean world making our kids sick? That's a question a recent Swedish study examined, and the results suggest that certain lifestyle choices may have a significant effect on whether children develop allergies.
Specifically, the study—conducted in the Swedish cities of Mölndal and Kiruna and involving 1029 children aged 7 to 8 years—showed an association between hand-washing dishes and reduced risk of eczema and asthma.
According to the data, 38% of kids from homes with dishwashers had a history of eczema, while just 23% of hand-washing homes reported the same condition. Asthma followed a similar pattern: 7.3% in homes with dishwashers, and 1.7% in those without.
The study is part of ongoing research into the hygiene hypothesis, which argues that overzealously avoiding germs might be bad for you. The hypothesis suggests that exposing children to more microbes early in life can make them more tolerant to immune system irritants and prevent allergies from developing.
Dr. Bill Hesselmar of the University of Gothenburg, who led the study, has done quite a bit of research in this field. Prior to this study, he investigated whether parents who clean pacifiers with their mouths have children with fewer allergies. (Spoiler alert: It would seem that they do.)
While the results of this study show a strong correlation between hand-washing and increased allergy resistance, there are many other factors to consider. The study notes that the positive association was amplified if the same households also ate more fermented foods, or if they bought food directly from farms.
It goes without saying that there are also risks associated with lower standards of hygiene, but this study could serve as further evidence that you don't need a bottle of hand sanitizer in every room to have a healthy immune system.