A Northwestern University study suggests that American parents should ease up on antibacterial soap and perhaps allow their little ones a romp or two in the mud in getting more exposure to everyday germs. The exposure to infectious microbes early in life could actually protect individuals from cardiovascular diseases that can lead to death as an adult.
“Contrary to assumptions related to earlier studies, our research suggests that ultra-clean, ultra-hygienic environments early in life may contribute to higher levels of inflammation as an adult, which in turn increases risks for a wide range of diseases,” said Thomas McDade, lead author of the study and associate professor of anthropology in Northwestern's Weinberg College of Arts and Sciences.
Research suggests that inflammatory systems may need a higher level of exposure to common everyday bacteria and microbes to guide their development. “In other words, inflammatory networks may need the same type of microbial exposures early in life that have been part of the human environment for all of our evolutionary history to function optimally in adulthood,” said McDade.
Levels of the protein rise in the blood due to inflammation, an integral part of the immune system's fight against infection. Research mostly has centered on the protein as a predictor of heart disease, independent of lipids, cholesterol and blood pressure, though researchers still dispute that association and have been looking at excess body fat as a primary source of pro-inflammatory cytokines that produce CRP and behavioral factors related to diet, exercise and smoking.
“In the U.S we have this idea that we need to protect infants and children from microbes and pathogens at all possible costs,” McDade concluded. “But we may be depriving developing immune networks of important environmental input needed to guide their function throughout childhood and into adulthood. Without this input, our research suggests, inflammation may be more likely to be poorly regulated and result in inflammatory responses that are overblown or more difficult to turn off once things get started.”
Early Origins of Inflammation: Microbial Exposures in Infancy Predict Lower Levels of C-reactive Protein in Adulthood, will be published online December 9 in the journal Proceedings of the Royal Society B: Biological Sciences.