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Without question the worst part of cooking is cleaning up. However, thanks to the dishwasher, many people are able to avoid a lot of the hassle of scrubbing, soaking and hands that smell like old sponge. Unfortunately these super machines could be making us sick. According to a new study, dishwashers may actually increase the incidence of chronic disease. According to the “hygiene hypothesis,” people in developed countries are just too clean. Our propensity to use hand sanitizers and strong detergents as well as lack of exposure to animals is wreaking havoc on our immune systems. This latest study, which looked at children in Sweden, found that kids who grow up in households that wash dishes by hand rather than with machines are significantly less likely to end up with chronic problems like asthma, hay fever and eczema.

Here’s the thinking as it relates to how we wash dishes: An automatic dishwasher cleans dishes better than a human ever could. We also handle less dirty dishes if we just have to scrape them and put them in the machine. And, as with hand sanitizer, our body doesn’t learn how to develop protection against some harmful bacteria because it doesn’t experience enough of those bacteria.

The researchers performed the study on kids because their immune systems are still developing. And while these results don't mean you should give up your dishwasher, they do imply that we should consider counteracting over-sterilzation.

For example, eating more fermented foods and those that came straight from a farm or farmer’s market increased the “protective” effect for subjects. The full study will be released today in the most recent issue of Pediatrics.

[h/t NPR]