A new study about the long-term benefits of everyday germs may have parents thinking twice before slathering their kids with antibacterial soap.
Researchers at Northwestern University found that growing up in a hyper-clean environment may actually make children more susceptible to cardiovascular disease later in life. Their findings were published Wednesday in the Proceedings of the Royal Society B: Biological Sciences.
“What may be lacking for kids in the U.S. is exposure to common, everyday microbes that have been part of our environment for all of our evolutionary history,” says Dr. Thomas McDade, the study’s lead author and an anthropology professor at Northwestern. “Kids who live in really sanitary environment are being deprived of what their immune systems need to really develop.”
An analogy is helpful: To help along cognitive and social development, parents are told to engage their babies by talking to them, playing with them, hanging up mobiles – in other words, the “Baby Einstein” theory.
Building a healthy immune system works the same way, McDade says. Exposure to germs, dirt, and other microbes early in life – especially in the first year – helps the body learn how to regulate its immune responses.
“Without that exposure and that engagement early in life, the system just can’t develop the way it’s supposed to,” says McDade, who is also a faculty fellow at Northwestern’s Institute for Policy Research.
The researchers analyzed more than 20 years of data from the Philippines, where childhood diseases are more common, for levels of C-reactive protein (CRP) a protein released by the immune system that, in high levels, has been linked to increased risk for cardiovascular disease. Filipino young adults had levels at least 80 percent lower than their American peers.
McDade says the research suggests that by being exposed to more germs in early childhood, kids in the Philippines developed stronger and more stable immune responses.