Saliva Can Be an Indicator for Aging. A Review


  • Nahed A. Khalil Professor, Dental Anatomy and Oral Histology Division, Oral Diagnostic Sciences Dept., Faculty Of Dentistry, King Abdul-Aziz University Jeddah, Saudi Arabia and Faculty of Oral and Dental Medicine Cairo University, Egypt.


Aging, Saliva, dry mouth, Rheology, Tribology, Salivary metabolites


Saliva plays an important role in the oral processing of food and consequently the sensory and textural experience. The ability to speak, swallw, masticate, taste food, and maintain a healthy oral cavity is related to the presence of saliva. Reduction in saliva results in many symptoms whose combined effect can drastically reduce quality of life. Several researches confirmed the presence of histological
changes in the salivary glands induced by aging. Consequently, it is often assumed that the secretion and properties of saliva change with age, which can result in dry mouth conditions and taste aberrations. Such changes may result in reduced nutrient intake and malnutrition besides adversely affecting the quality of life. Some researchers have reported age-dependent changes on quantity (bulk
salivary flow rate) as well as quality of saliva (e.g., composition, viscosity, lubrication) in healthy elderly individuals. However, recent research work has paid attention to the age-related salivary metabolites. This is due to lack of adequate understanding and characterization of endogenous factors, that is, the age-related changes in saliva, which may influence oral processing of food and
subsequently nutrient intake. Few studies have comprehensively identified age-dependent changes in salivary metabolites. Hence, this review aims to survey the current state of knowledge concerning age- dependent changes in salivary glands structure, quantity and quality of saliva as well as salivary metabolites. The latter through analysis of saliva may act as an indicator for aging in population. Such insights will not only have clinical implications for maintaining optimal oral health in elderly population, but also serve to optimize food and to satisfy the needs of growing aging population.