Saliva, however, is more concentrated than saline, so it would make you thirstier if you drank it, Horovitz said. That's because it would cause the fluids in your body to flow toward the concentrated saliva, and not toward your dehydrated cells. "In other words, saliva is not watery enough," Horovitz told Live Science.

Is spitting bad for your health?

Spit screening

According to the researchers, spit contains the same protein, called C-reactive protein, that indicates a risk of heart disease when found in blood at elevated levels, and spit can therefore give a rough proxy of a patients' heart health.

How much of spit is water?

If you're wondering what saliva is made of, it's 99% water. This is no surprise considering the body is made of 60% water. The remaining 1% of saliva contains digestive enzymes, uric acid, electrolytes, mucus-forming proteins, and cholesterol.