HEALTH AND WELL-BEING
Chemosensory dysfunction can have a profound impact upon health status and quality of life. Sensory deficits can lead to inadequate nutrition due to loss of enjoyment of food or to ingestion of harmful or spoiled food and beverages. And, risk of injury from fires, inhalation of toxins, or exposure to gas leaks is higher in individuals whose loss of smell renders them unable to detect the presence of harmful substances in the environment. Although taste and smell disorders occur in a substantial proportion of the population, knowledge of the nature and causes of these disorders is incomplete.

In order to better understand the nature and causes of taste and smell disorders, Monell collaborates with Thomas Jefferson University to operate a Chemosensory Clinical Research Center (CCRC). Supported by a grant from the National Institutes of Health, the CCRC staff evaluates patients with loss, diminution, or distortion of the senses of taste and smell. To date, more than 1,000 patients have been evaluated at the CCRC, resulting in one of the world’s largest databases on chemosensory dysfunction. Upon referral by physicians and dentists, patients undergo evaluation of their chemosensory capabilities and otolaryngological status. They may also receive dental or other specialized medical examinations. A complete report of findings and treatment recommendations is then provided to the referring physician.

Disorders of the senses of taste and smell may be associated with many possible causes including viral or bacterial disease, trauma, head injury, aging or use of some prescription pharmaceuticals. Increased understanding of chemosensory disorders gives Monell’s scientists insight into the fundamental processes underlying normal function, and also promotes the development of successful treatment strategies.

An important function of the CCRC is to provide a point of contact and coordination for scientists and clinicians. For example, healthy clinic volunteers donate olfactory tissue via biopsy for laboratory research at Monell. Collaborative projects between basic research scientists and clinicians use this tissue to study changes occurring elsewhere in the central nervous system in diseases such as Alzheimer’s or bipolar depression.

Other clinical studies are conducted in collaboration with the University of Pennsylvania. The effects of smell and taste on digestion, metabolism, and glucose utilization are important areas of study.

The human body produces a number of volatile chemical compounds, and researchers at Monell are working to determine the origins and functions of human body odors. Patients with malodor disorders can have a diminished quality of life, with social, psychological, and business implications, and often the causes of their disorders elude standard clinical knowledge. In collaboration with clinicians, scientists at the Center offer a diagnostic work-up to patients with malodor problems from throughout the world. Causes identified range from a rare genetic disorder known as trimethylaminuria to the presence of bacteria causing formation of tongue plaque. Monell scientists can often recommend treatments, dietary changes or other methods of reducing malodors.

Ongoing research projects at Monell related to health and well-being include:

• A follow-up tracking program for all patients seen at the CCRC to monitor chemosensory function or recovery
• Efforts to determine the effect of disease or injury on olfactory function and to identify factors influencing recovery of damaged cells
• Evaluation of receptor cell function in normal aging and in diseases such as Alzheimer’s and bipolar depression
• Experiments to elucidate the nature and causes of taste and smell problems associated with the use of medications
• Development and evaluation of treatment options for human malodors, including trimethylaminuria
• Study of the influence of body odors on human reproductive function
• Evaluation of the effect of chemosensory signals on digestion, metabolism, and glucose utilization in healthy individuals and in disease states such as obesity and diabetes