Researchers, from the University of Gothenburg, looked at whether certain behaviours that expose children to bacteria in their early years, can protect them from allergies in later life.
They monitored almost 1,000 children and their parents, looking for trends such as feeding children food purchased directly from farmers or fermented foods.
And if parents washed their dishes by hand. Each child’s allergic conditions including asthma, eczema and hay fever were also examined.
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The findings revealed that children, raised in households where dishes were washed by hand, had half the rate of allergies.
And that this association increased dramatically in the case of children who also ate fermented foods or food sourced directly from farmers.
According to lead researcher Bill Hesselmar, these behaviors may expose children to bacteria that helps strengthen their immune systems.
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He believes that although the cleaning effect of dishwashers is a positive thing, the task of hand-washing dishes may leave behind some bacteria that could have immune-boosting benefits.