Saliva, or spit, plays a significant role in maintaining oral health. It is derived from blood and acts as the bloodstream of the mouth. What this means is, like blood, saliva helps build and maintain the health of soft and hard tissues. When saliva flow is reduced oral health problems such as tooth decay and other oral infections can occur. Chewing is the most efficient way to stimulate salivary flow. It causes muscles to compress the salivary glands and release saliva.

Saliva also:

• Washes away food and debris from teeth and gums
• Helps moisten and break down food to ease swallowing and enhances ability to taste
• Provides disease-fighting substances throughout your mouth to help prevent cavities and other infections
• Helps keep the surface of your teeth strong by providing high levels of calcium, fluoride and phosphate ions at the tooth surface.

In addition to keeping your mouth healthy, saliva may contain indicators of health concerns as well. Since it shares many properties with blood, the use of saliva to detect and diagnose oral diseases and other diseases that could affect your general health is being studied. Researchers have reported promising results in the use of saliva for the diagnosis of breast cancer, oral cancers, gum disease and viral hepatitis. Saliva is already used for rapid HIV testing.

The U.S. National Institutes of Health has targeted salivary diagnostics as an important area of development and is researching its many potential uses.