A nose for health

UVic grad Jamie Knight, BA ’15, MSc ’17, is championing smell testing as a way to gain insights into brain health.

From springtime blooms, to the aroma of a summer campfire, to the fragrance of fall leaves, our sense of smell plays a vital role in our lives. A decline in smell can not only affect everyday safety, but also diet and nutrition, physical well-being and relationships. Research shows we bond with our partners and children through smell. We also stay safe by using our sense of smell to detect food spoils, smoke or gas.

Jamie Knight, UVic PhD candidate in psychology, is fascinated by the connection between smell and brain health. She suggests smell has been underutilized by the medical community for over 30 years. The connection between loss of smell and cognitive decline was first reported in the mid-1980s by Dr. Richard Doty, a researcher from the University of Pennsylvania. Interest in olfactory research only recently came back into the spotlight when health professionals flagged the loss of smell as a COVID-19 symptom.

“Since COVID, more research funders have come forward and now more people are interested in the research on how smell and the brain work,” says Knight. 

Knight, who earned a BA in psychology in 2015 and then a Master of Psychology in 2017, began her work with smell when she realized how much was still unknown about the onset of dementia and the connection with a loss of smell.

A change in our sense of smell can be an early marker of cognitive decline. Sometimes 10 to 15 years before any other symptoms appear.”

—UVic psychology PhD candidate Jamie Knight 

As our population ages, rates of dementia, Alzheimer’s and Parkinson’s diseases continue to rise in Canada. Medical research focuses on cures, but inexpensive tests such screening for a loss in sense of smell could potentially improve health outcomes if testing is done early.

“People with Alzheimer’s disease tend to have no sense of smell,” says Knight. “The earliest brain areas impacted by Alzheimer’s disease pathology are also important olfactory processing areas.”

Since the olfactory pathway maps onto the same area affected by Alzheimer’s disease, Knight is excited about using functional magnetic resonance imaging (fMRI) on the brain to learn more about the connection between smell and neurological diseases.

“FMRI studies allow researchers to further explore connections between smell and cognitive functioning and brain degeneration,” says Knight.

The fMRI measures brain activity while a person is doing a task, such as a smell test. The ability to identify a smell is the cognition side of the equation. Knight hypothesizes that if we cannot match the name of the smell to the odour, it could be a sign of impaired cognition.

The good news is that training our olfactory system does improve our sense of smell, but more research is needed to determine if it also improves cognition. 

“There are big implications for dementia if we can show cognition gets better as our sense of smell improves,” says Knight, whose work is funded by AGE-WELL NCE Inc. and the Canadian Institutes of Health Research.

For most people, sense of smell may be overlooked and not explored unless you are a chef or sommelier; however, most of us would want to know if we are headed toward dementia.

Currently, our health care system is not promoting testing sense of smell, yet all it takes is a simple test that would not even require a physician to administer it. According to Knight, people in their mid-40s should be encouraged to start testing early.

“My dream is to have locations, much like we do with hearing clinics, for people to test their smell every couple of years,” says Knight. 

Find out more at olfactoryhealth.org