The idea that beards are dirtier than clean-shaven faces has been floating around for decades, says John Tregoning, professor of vaccine immunology at Imperial College London. There is even research that shows people perceive bearded men as less hygienic: one study found restaurant customers rated waiters with facial hair as dirtier. Science doesn’t necessarily back that up, though.
One of the earliest studies on the subject, published in 1967, looked at how much bacteria could be recovered from men’s faces after being artificially sprayed on to their skin. Researchers compared washed and unwashed faces, both with and without beards. The dirtiest combination wasn’t with a beard: most bacteria was recovered from unwashed clean-shaven faces, followed by unwashed bearded faces, washed bearded faces and finally washed clean-shaven faces.
