Effects of Caffeine on Salivation

Introduction:

Saliva has an important homeostatic role in the oral cavity. Hyposalivation can lead to diseases such as caries and mucous membrane candidiasis as well as difficulties in speech, mastication and deglutition. Like all exocrine secretions, salivary production is under the control of the autonomic nervous system, but physical factors such as hypovolemia and dehydration can also playa role. Thus, various systemic conditions, medications, and psychological factors can affect salivary output .

Caffeine, a natural derivative of coffee beans and tea leaves, is a methylxanthine with proven activity on the central nervous system and the smooth muscle cells of the cardiac, respiratory and digestive organs. Its effects mostly parallel the adrenergic pathway and include increased arterial blood pressure and cardiac output, and decreased gastrointestinal muscle tone. Following this teleological path, it would be expected that caffeine had a significant, dose-dependent effect on reducing salivary secretion.

This effect has been an accepted tenet of the treatment of hyposalivation yet surprisingly it has not been confirmed scientifically. Further, knowing the size of the effect of caffeine on salivation can inform treatment advice to patients.

We studied the effects of caffeine ingestion on unstimulated andstimulated whole salivary production in a group of healthy adults. We hypothesized that caffeine would significantly decrease salivation in both the stimulated and the unstimulated settings after an overnight fast.