Electronic Thesis and Dissertation Repository


Doctor of Philosophy


Health and Rehabilitation Sciences


Dr. Ruth Martin


Eating and maintaining optimal nutrition are essential to health and quality of life. In both health and disease, eating is influenced by multiple factors including swallowing, oral health, and saliva production. Perturbations to any, or all, of these inter-related factors may result in consequences that negatively affect the health and wellness of an individual. Eating and swallowing impairment are common symptoms of neurodegenerative diseases such as dementia, and these symptoms are associated with a host of negative sequelae such as malnutrition, dehydration, aspiration pneumonia, and reduced quality of life. The studies reported in this dissertation explored elements of eating and swallowing, saliva production, and saliva modulation in healthy individuals and in persons with Alzheimer’s disease (AD).

This dissertation is composed of three studies. First, a scoping review methodology was used to examine literature that addressed autonomic nervous system and/or swallowing dysfunction in individuals with AD. Then, systematic review and meta-analysis methodologies were used to examine a potential effect of aging on saliva production. Finally, a within-subjects methodology was used to examine the modulation of salivary flow by tooth brushing in healthy older adults.

In the first study, swallowing dysfunction and autonomic nervous system dysfunction, including salivary flow dysfunction, were found to occur in persons with AD. In the second study, salivary flow was found to be reduced in adults aged 60 years and older who were free of major systemic disease. In the third and final study, the use of manual and electric tooth brushing was found to increase whole salivary flow rates in adults aged 60 years of age and older who were free of major systemic disease.

The results of this dissertation have very important implications for the future research and management of eating and swallowing, oral health, and saliva production in a variety of populations, including aging individuals and persons with AD.