In the sixteenth and seventeenth centuries, facial hair had been viewed as a form of bodily waste. It was regarded as resulting from heat in the liver and reins, and was partly a signifier of a man’s virility. Equally though, as a waste product, shaving it off might be seen as healthy as it was another way of ridding the body of something potentially harmful.
By 1850, however, doctors were beginning to encourage men to wear beards as a means of warding off illness. As Oldstone-Moore points out, the Victorian obsession with air quality saw the beard promoted as a sort of filter. A thick beard, it was reasoned, would capture the impurities before they could get inside the body. Others saw it as a means of relaxing the throat, especially for those whose work involved public speaking. Some doctors were even recommending that men grew beards to avoid sore throats.
For the unfortunate and patchy, there was always "Professor Modevi's success-guaranteed Beard Generator." [AW]