Health benefits of saliva: a review

The aim is to present a review of the literature on human saliva composition, flow rates and some of the health benefits of saliva, with emphasis on studies from our laboratory that have looked at effects of age and age-related diseases on saliva output and composition.

Saliva influences oral health both through its non-specific physico-chemical properties, as well as through more specific effects. The proline-rich proteins, statherin and the histatins are salivary proteins that influence calcium phosphate chemistry, initial plaque formation and candida infection. Increases or decreases in mastication may affect saliva output. Our cross-sectional studies of saliva in a large population-based study cohort (N=1130) indicate that there is an age-related decline in saliva output for unstimulated whole, stimulated parotid, unstimulated submandibular/sublingual and stimulated submandibular/sublingual saliva, as well as some compositional alterations in anti-microbial and other proteins. Some of these alterations also appear to be specific for certain age-related medical conditions, such as diabetes mellitus.

These studies and data presented confirm the importance of saliva in maintaining a healthy oral environment; the practitioner is encouraged to consider saliva output and medical conditions that may compromise it as part of routine dental treatment planning.