It’s not unusual for people to lose some degree of hearing and vision as they age, and it turns out our sense of smell also declines over time.
Accidents and disease might also be to blame when people have trouble detecting odors.
Until now, there have been no good treatments, but scientists at Virginia Commonwealth University say they may have a solution.
If you search YouTube for Cochlear Implant, you’ll find a video of 26-year-old Amy – a deaf woman, hearing sound for the first time.
The technology that makes hearing possible involves a processor converting sound waves to electronic signals that are delivered to that part of the brain associated with hearing. At Virginia Commonwealth University, Professor Richard Costanzo says a similar approach could be used to restore a sense of smell.
“The gas sensors will pick up odors and will stimulate the brain with different patterns, and we’ll say, ‘What does that smell like?’ And they’ll say, ‘Well that smells kind of like a flower or a rose,’ and we’ll try a different pattern and say, ‘What does that smell like? And that might smell like an orange or an apple?’ Then we’ll match the two – what the sensor picks up, the processor will code that and know the proper simulation for an apple or an orange.”
Costanzo is working with Dr. Daniel Coelho, director of VCU’s cochlear implant center, to find a fix for the loss of smell. "It’s a lot more common than you might think," Coelho says. "There are estimates that up to and over two percent of the U.S. population has a significant loss of smell."
And that means trouble tasting food. "Ninety percent of what we call flavor is related to smell, and if you’ve ever had a cold you know that food doesn’t taste good, not because you can’t taste but because you can’t smell," according to Coelho.
There are also safety concerns for people unable to smell a gas leak or spoiled food. Sometimes, Costanzo says, the loss of smell results from a virus, head injury or whiplash. "The brain moves back and forth in the skull, and the small, delicate olfactory nerves coming from the nose can get severed or torn, and that disconnects the nose from the brain," Costanzo says. The nerves are so delicate they can’t be surgically repaired.
A decline in smell may also be linked to aging. Beginning in their mid 50’s, he says, people may experience a 10-20% loss, and if they live into their 80’s or 90’s, smell can decline by 50-60%.
Finally, Coelho says, there could be a connection to thought and learning. "Anybody knows that when you smell something it brings up memories from your childhood that you hadn’t thought about in years."
So it might be possible to fend off dementia by protecting our sense of smell. Whatever the future holds, Costanzo says the work he and Coelho are doing at VCU’s Center for Smell and Taste Disorders is promising. "I’ve seen patients for the last 30 years and up until we really don’t have a surgical approach to repairing these damaged nerves, so by bypassing the damage and coming up with something like a cochlear implant, we think in the future we might be able to restore the sense of smell."
They’re now working on a prototype and hope to begin testing on humans in a few years.