Current state of saliva biomarkers for aging and Alzheimer's disease.

INTRODUCTION: Aging is the primary risk factor for major human pathologies, including cancer, diabetes, cardiovascular diseases, and neurodegenerative diseases such as Alzheimer's disease (AD). AD is a progressive degenerative disorder of the brain and is the most common form of dementia.

METHODS: To-date no simple, inexpensive and minimally invasive procedure is available to confirm with certainty the early diagnosis of AD prior to the manifestations of symptoms characteristic of the disease. Therefore, if population screening of individuals is to be performed, easily accessible tissues would need to be used for a diagnostic test that would identify those who exhibit altered or aberrant aging profiles that may be indicative of AD risk, so that they can be prioritized for primary prevention. This need for minimally invasive tests could be achieved by targeting saliva, since it is now well recognized.