Human saliva contains proteins like histatin that have antibacterial properties and can promote wound healing. Tears contain similar compounds, including lysozyme, which helps fight infection.
Your Saliva Actually Helps Heal Wounds
Next time someone gives you a strange look for licking a paper cut, you can tell them there's actual science behind it. Human saliva isn't just spit—it's a surprisingly sophisticated cocktail of healing compounds.
Your Mouth's Secret Pharmacy
Saliva contains a protein called histatin, which researchers have found promotes wound closure and has antibacterial properties. In laboratory studies, wounds exposed to histatin healed significantly faster than untreated wounds.
But histatin isn't working alone. Your saliva also contains:
- Lysozyme — an enzyme that breaks down bacterial cell walls
- Lactoferrin — binds to iron, starving bacteria of a nutrient they need
- Immunoglobulin A — antibodies that neutralize pathogens
- Growth factors — proteins that stimulate tissue repair
Why Mouth Wounds Heal So Fast
Ever notice that cuts inside your mouth heal remarkably quickly? A study published in Science Translational Medicine found that oral wounds heal faster than identical skin wounds—sometimes healing completely in just a few days.
This isn't just because of saliva. The moist environment and rich blood supply in your mouth help too. But saliva's healing proteins play a starring role.
Tears: Not Just for Crying
Your tears share some of saliva's superpowers. They contain lysozyme in even higher concentrations than saliva, which is why your eyes rarely get infected despite being exposed to the air all day.
Tears also contain growth factors and other compounds that promote healing. It's your body's way of protecting one of its most vulnerable organs.
Should You Actually Lick Your Wounds?
Here's where it gets complicated. While saliva has healing properties, your mouth also contains over 600 species of bacteria. For minor cuts and scrapes, a quick lick is probably harmless. For deeper wounds? Stick with soap, water, and proper bandaging.
The healing compounds in saliva are also being studied for medical applications. Researchers are exploring whether synthetic versions of histatin could be used in wound-healing treatments, potentially helping patients with diabetes or other conditions that impair healing.
So while you probably shouldn't make licking wounds your go-to first aid strategy, your instinct isn't entirely misguided. Evolution gave you a mouth full of medicine—you just need to use it wisely.