A lack of exposure to germs in childhood could increase the risk of disease in adulthood, suggests a new study.
"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," including heart disease, said lead author Thomas McDade, of Northwestern University in Illinois, Agence France Presse reported.
He and his colleagues found that infants and toddlers in the Philippines had far more infectious diseases than those in the United States, but levels of C-reactive protein -- a marker of inflammation -- are at least 80 percent lower in Filipino adults than in American adults.
"CRP concentrations are incredibly low in Filipinos compared to people in the United States and that was counter to what a lot of people would have anticipated because we know that Filipinos have higher exposure to infectious diseases," McDade told AFP.
The study appears online in the journal Proceedings of the Royal Society.