View as List 9 Facts About Saliva

  • drooling baby?>

    Less poetic than tears or blood, saliva is an essential bodily fluid that’s easy to take for granted. Here are some tidbits about spit. 

  • 1

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    Saliva is as much as 99 percent water, with a complex mix of proteins, minerals, vitamins, hormones, and other substances—along with traces of food, toothpaste, and whatever else you put in your mouth. 

  • 2

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    Hundreds of salivary glands in the mouth produce, on average, about a quart of liquid a day—enough to fill two medium-size bathtubs a year. But saliva production varies considerably from person to person, by time of day, and under different circumstances. Notably, you produce less saliva when you are sleeping or dehydrated and, typically, as you age. 

  • 3

    man with silly smile, showing tongue?>

    Mucins—protein molecules that might be compared to microscopic ball bearings—are the key lubricating components in saliva. They help you chew, speak, and swallow. They stick to the teeth and help shield them, to some extent, from bacteria and acids and thus from cavities. 

  • 4

    older woman covering mouth?>

    Saliva protects teeth and gums, lubricates the mouth, and helps regulate the acid balance of the mouth. It provides the environment in which tooth minerals can be replaced. That’s why chronic dry mouth can cause cavities and gum disease. 

  • 5

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    Saliva contains enzymes that start the digestive process by helping to break down starches and fats. It lubricates the food you are chewing and enables you to swallow it. 

  • 6

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    Food molecules must dissolve in saliva in order to be recognized by taste buds. 

  • 7

    man with toothache?>

    Saliva contains antibodies that fight germs, along with substances that promote skin cell growth and blood clotting. That’s an important reason why wounds in the mouth usually stop bleeding and heal faster than wounds elsewhere on the body. 

  • 8

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    When you are nervous or frightened, saliva production is reduced. Hot weather, inadequate fluid intake, strenuous exercise, many medications, and some medical conditions can result in decreased saliva production and potentially dry mouth. Smoking or breathing through your mouth dries up saliva.

  • 9


    Saliva can be analyzed to monitor alcohol intake, smoking, and drug use. It may also be useful in diagnosing disease. For instance, there are FDA-approved saliva tests to detect antibodies to HIV and the hepatitis C virus. Someday diagnostic saliva tests may be as common as blood tests.