Is it healthy to literally "lick one's wounds"? Does human spit contain any chemicals that are anti-bacterial or antiseptic? Would you recommend the practice if, for example, a Bactine-less camper has the misfortune to be mauled by a bear?
Illustration by Slug Signorino
Cecil is of two minds about this. On the one hand, researchers at the University of Florida at Gainesville have discovered a protein called Nerve Growth Factor (NGF) in the saliva of mice. Wounds doused with NGF healed twice as fast as untreated, unlicked wounds. So in a few species, at least, spit does have some curative powers. NGF has not been found in human saliva, but researchers do note that human spit contains such antibacterial agents as secretory IgA, lactoferrin, and lactoperoxidase. It has not yet been shown that licking your wounds actually disinfects them, but on the other hand it probably won’t do you any harm.
At least I think it won’t. See, the one problem is that your mouth also contains “anaerobic” bacteria, which thrive in airless environments such as the nooks and crannies of your teeth and gums. Normally these don’t find their way into your saliva, but if they do, you’d be better off throwing yourself on a punji stake. So virulent are the anaerobic microbes that hospital emergency room personnel consider human bites to be among the most serious types of trauma. If not treated promptly this kind of wound can result in severe infection, sometimes so bad that the affected finger, or even the hand or arm, has to be amputated. The danger exists even if the spit in question is your own. Cecil knows of one case of a woman who managed to infect herself by chewing obsessively on her fingernails.
So in other words, licking your wounds either isn’t so bad or it’ll kill you. If you’re one of those types with a low tolerance for ambiguity, maybe you should just forget it and try the old Boy Scout method — namely, letting the wound bleed briefly before bandaging it, thus allowing any contaminants to be washed out of the damaged area.
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