Your body, folks, is a pretty complex ecosystem, with over 100 trillion microbes that need balance for the best state of health. The entire system of protozoa, viruses, fungi and bacteria that lives in your body even has its own term, the “human microbiome.”
While the idea of bacteria and viruses tends to bring images of dirt and disease to mind, the truth is your body needs some types of “good” bacteria and also exposure to “bad” bacteria, viruses and other microbes so your immune system knows how to handle them properly. When your body has a unusual immune system response to a typical microbe, the result is an allergic reaction.
These days, with the emphasis on antibacterial soaps and sanitizers, experts are concerned that people are not getting enough normal microbe exposure, which is needed to stimulate the immune system so it develops a tolerance and reduces the risk of allergies, including reactions to food. Another potential example of this concern is demonstrated in a recent study on the connection between using a dishwasher and the development of allergies.
This study, which involved 1,000 children in Sweden, was conducted by the University of Gothenburg research team and published in the Official Journal of American Academy of Pediatrics (https://pediatrics.aappublications.org/content/early/2015/02/17/peds.2014-2968). Researchers found that the children who had more exposure to microbes were less likely to develop allergies, and this included the exposure that comes with the hand washing of dishes. A typical dishwasher is more just than a convenience appliance: it also uses water that is too hot for a person to touch and therefore kills more germs and leaves dishware cleaner than washing by hand.
The researchers found that in homes where the dishes were always hand washed, the rate of allergies for the children was about 50 percent of the rate of children with allergies in homes where dishwashers were used. In addition, children using dishes that were washed by hand were also less likely to develop hay fever, asthma and eczema than children using machine-washed dishes. This leads them to conclude that less-efficient dish washing–such as by hand–can indue more tolerance to allergies and other conditions because of the increased microbial exposure.
Of course, no one is saying dump the dishwasher right away–it can be a big benefit in a busy household and in homes where anyone has a condition that makes them more susceptible to illness. But, before you go to use that hand sanitizer for the tenth time today, consider if you really need to.