Many people believe applying saliva to a wound aids healing, a practice observed in both humans and animals. However, scientific understanding reveals that while saliva contains certain compounds, its application to external wounds is ineffective and potentially detrimental. This article explains why this common folk remedy is not supported by science.
What Science Says About Saliva and Wounds
Human saliva is mostly water, but it also contains electrolytes, mucus, white blood cells, and various enzymes. These enzymes, like amylase and lingual lipase, primarily aid in food digestion within the mouth, not in healing external tissues.
Saliva also contains substances with antimicrobial properties, such as lysozyme. Antibodies like secretory IgA and IgG are also present, contributing to the mouth’s immune defense. These components primarily maintain oral hygiene and protect against pathogens in the mouth.
Saliva also contains growth factors and proteins like histatins. In laboratory settings, histatins have shown some ability to promote cell spreading and migration, potentially speeding up wound closure.
Despite these potentially beneficial compounds, their concentrations in saliva are insufficient to significantly impact external wound healing. The oral cavity heals rapidly with minimal scarring, a characteristic often mistakenly attributed solely to saliva. Oral healing mechanisms do not directly translate to broad benefits for wounds elsewhere on the body, as conditions in the mouth differ from external skin.
Why Saliva Can Be Harmful and Proper Wound Care
Applying saliva to an external wound is primarily concerning due to the many bacteria in the human mouth. Saliva contains millions of bacteria and other microorganisms. While harmless in the mouth, these microorganisms can cause significant problems if introduced into an open wound.
Introducing oral bacteria into a break in the skin significantly increases the risk of infection. Human bite wounds, for instance, have high infection rates due to the transfer of these oral microorganisms. Infection can lead to inflammation, increased pain, delayed healing, and in severe cases, cellulitis or systemic infections.
Given these risks, proper first aid for minor wounds is crucial. First, wash your hands with soap and water to avoid introducing contaminants. If the wound is bleeding, apply gentle, direct pressure with a clean cloth until the bleeding stops.
Next, clean the wound by rinsing it under cool, running water to remove dirt and debris. Wash around the wound with mild soap, but avoid getting soap directly into it. Do not use harsh antiseptics like hydrogen peroxide or iodine, as these can irritate the tissue.
After cleaning, apply a thin layer of antibiotic ointment or petroleum jelly to keep the wound moist and help prevent scarring. Cover the wound with a sterile bandage, changing it daily or whenever it becomes wet or dirty.
Monitor the wound for signs of infection, such as increasing redness, swelling, warmth, pain, or drainage. Seek medical attention if these symptoms develop, or if the wound is deep or does not stop bleeding.