In a long-term study published in The Proceedings of the Royal Society B, U.S. researchers suggest that over-cleanliness could make babies more prone to inflammation later in life, and in turn raise the risk for stroke and heart disease.
Thomas McDade’s team studied more than 1,500 people in the Philippines who had health surveys at age two and then again at age 20. The team tested them for C-reactive protein (CRP), a marker of inflammation. They found that the more pathogens the people had encountered before age 2, the less CRP they had at age 20. Every episode of diarrhea back then cut the chance of higher CRP later by 11 per cent; every two months spent in a place with animal feces cut it by 13 per cent. Being born in the dusty, dirty dry season cut the chance by a third.
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