Parents who wash dishes by hand, instead of in a dishwasher, are less likely to have kids with allergies, according to a new study from Sweden.
While the researchers can’t say avoiding dishwashing machines prevents childhood allergies, they suggest that bacteria left on hand-washed plates may teach the body to tolerate its environment.
Other studies have suggested that growing up on farms and living in developing countries reduce a child’s risk of allergies, the researchers wrote February 23 in the journal Pediatrics.
The study’s lead author told Reuters Health by email that while those earlier findings are interesting, they can’t realistically be used to reduce allergies among children. For example, you can’t tell parents to buy a farm.
"We are trying to find sources of ‘harmless’ microbial exposures in daily life that may be good enough to reduce allergy in children who are otherwise not exposed to a rich microbial flora in the same way as farm-living children," said Dr. Bill Hesselmar of the University of Gothenburg.
Hesselmar and his colleagues analyzed data from a 2007 survey of Swedish parents of 1,029 children ages seven and eight.
About 12% usually washed dishes by hand; 84% usually used a dishwashing machine.