by Roopal Luhana
ids may be “too clean” these days. As parents worry about germs, illnesses, infections and keeping their little ones safe, they may unwittingly over-sterilize their children’s environments, which may not be good for their children’s long-term health.
Some research shows that those children who are exposed to more dirt, animal dander, dust and other “dirty” things may be less likely to suffer from a number of health problems, including asthma, allergies and eczema.
The Hygiene Hypothesis: Kids Need More Dirt
The idea that children need more, not less, exposure to dirt, mud and animal dander can be traced back to the “hygiene hypothesis” developed by David P. Strachan, a professor of epidemiology. Strachan discovered through his studies that children living in larger households were less likely to suffer from hay fever and eczema. He theorized that the children in the larger families were exposed to more infectious agents through their siblings, and thus developed stronger immune systems that protected them against allergic diseases.
This theory received support when other research produced similar findings. In a 2016 study, scientists tested individuals from two farming communities—the Amish, who use traditional farming practices, and the Hutterites, which use industrialized farming practices.
Results showed that the prevalence of asthma and allergies were four to six times lower in the Amish children, levels of dust in the Amish households were 6.8 times higher than that in the Hutterites households and there were pronounced differences in the immune cells between the two groups.
Based on this evidence, parents have been advised to let their kids play with the dog and get their clothes dirty and muddy from time to time without rushing in with the antibacterial wipes. Today’s children are too protected, the theory goes, living indoors on sterilized surfaces rather than spending most of their time outside. This sort of upbringing can create an immune system that is too sensitive and likely to overreact later in life when exposed to something new.
It’s “Friendly” Microbes that Kids Need
Though some recent research has questioned the validity of the hygiene hypothesis, the idea that early exposure to microbes is healthy has persisted. The difference now is that scientists are being picky about which microbes kids should be exposed to.
Infectious agents like bacteria and viruses, for example, aren’t necessarily what the immune system needs, and may in fact be harmful. In a 2017 article published in the scientific journal Proceedings of the National Academy of Sciences (PNAS), researcher Megan Scudellari stated that epidemiological, experimental and molecular evidence support the idea that a “diverse range of ‘friendly’ microbes—not infectious pathogens—is necessary to train the human immune system to react appropriately to stimuli.”
It’s not that parents should try to expose their kids to microbes that can cause illness, this updated theory goes. They should still teach their kids to be aware of germs and to wash their hands to help them avoid potentially dangerous infections. Instead, it’s more about reducing the rise in allergic disorders by making sure children are exposed to the microorganisms that human beings rely on for good health.
Children are exposed to these microorganisms in utero, when they pass through the birth canal and while breastfeeding, and continue to gain exposure through contact with family members, when playing outside in the dirt, when interacting with pets and when sharing toys with friends.
The developing immune system receives healthy exposure in all these situations and is thus able to mature as it should. It learns what to attack and what to ignore as harmless and is less likely to overreact and cause symptoms related to allergic diseases and other sensitivities.
Tips for Parents to Help Children Grow Up Healthy
Considering the evidence we have now about optimal immune system development, some scientists recommend the following tips for parents:
» Get a dog and allow the children to interact with it. Other pets or farm animals can also provide health benefits.
» Encourage children to get outside and play regularly. Allow them to get dirty.
» Grow a garden with your children if possible. Even growing houseplants together can provide important exposure to dirt.
» Encourage kids to eat a diet rich in fruits and veggies, and high in fiber. Try to reduce sugar intake.
» Avoid the use of antibacterial sanitizing cleansers—use simple soap and water instead.
» Teach children to wash their hands and avoid sharing toys or other items from children who are sick, or from children they don’t know. But don’t worry if healthy siblings or friends are sharing.
» Continue to keep a clean home, keep food clean and fresh, and sanitize areas like the kitchen sink and counter tops and bathroom surfaces.