When it comes to bodily fluids, saliva is an unsung hero. We typically think of spit as something gross and germy, but the saliva that’s in our mouths is helpful for way more than just the action of spitting. Our saliva is an essential tool that allows us to chew, swallow, and digest comfortably. It also fights off infection, washes away potentially damaging food particles, and helps us taste wonderful flavors we enjoy every day.
You might be wondering what’s in our spit that makes it such a powerful tool. While saliva has a reputation of being less-than-hygienic, it’s actually about 99 percent water. The remaining 1 percent consists of electrolytes, digestive enzymes, small quantities of uric acid, cholesterol, mucus-forming proteins, and other organic substances. Much like your heartbeat, the production of saliva is controlled unconsciously by the autonomic nervous system, and healthy adults accumulate between two and six cups of spit a day.
Perhaps most importantly for overall health, spit is full of infection-battling white blood cells. In fact, recent studies show that neutrophils (a type of white blood cell) are most effective at killing bacteria if they come from saliva than anywhere else in the body. Just like the saying “lick your wounds” suggests, adding saliva to a wound provides additional bacteria-fighting power.
Similar to how it fights bacteria, saliva also helps your body fight off cavities. Spit contains tooth-strengthening calcium and fluoride, has the power to wash away particles of food that could get trapped, and can neutralize plaque acids, which reduce tooth decay and the possibility of cavities. If you want to maximize your spit production, chewing gum will increase the flow of saliva to further protect your oral health and keep your mouth sparkling clean.
Speaking of chewing, saliva is responsible for transporting dissolving food to your taste receptors. Without saliva, those receptors may dry out and affect the mouth’s ability to taste, or lead to longer term problems like dry mouth, or xerostomia. It’s possible that you may have experienced a dry mouth sensation in times of stress. During these times, the body’s main concern becomes eliminating that stress—not with eating—so the digestive system (including saliva production) slows down.
In its normal function however, salivation has five distinct phases, mostly triggered by food passing through the body:
- Cephalic: When you see or smell something delicious
- Buccal: The body’s reflexive response to the presence of food in the mouth
- Esophageal: The stimulation of the salivary glands as food moves through the esophagus
- Gastric: When something irritates your stomach—like when you’re just about to get sick
- Intestinal: When a food that doesn’t agree with you passes through the upper intestine
Next time you notice an increase in saliva production, think about which phase it might be, and be thankful for all of your spit’s beneficial qualities!