Recovering your sense of smell doesn’t happen overnight.
Since March, St. Louis Public Radio has been following a research study at Washington University designed to understand whether you can train the brain how to smell again. Using a technique known as “smell training,” researchers hope to reverse permanent smell loss.
As part of the study, patients sniff concentrated essential oils, such as lemon and clove, twice a day for three months.
Joe Weissmann is one of more than 20 participants enrolled. He finished his treatment in early August and said he has seen a small but noticeable change in his ability to smell.
“There have been improvements with more pungent odors or aromas,” said Weissmann, a retired sheet metal worker and south St. Louis County resident. “I was at a bonfire gathering, and when the smoke would blow in my direction, I would get a pretty good whiff.”
Weissmann believes his allergies to mold and tree pollen have hindered his progress, but he hasn’t lost hope.
“Though it’s been a slow progression for me, it’s positive, and it’s going in the right direction,” he said. “I’m going to stay optimistic.”
Another participant, Denise Turner, hopes to smell fresh-cut grass again someday.
“The smells that are in the air that let you know life exists, that’s what I miss most,” Turner said.
The Kansas City nurse lost her sense of smell about four years ago while recovering from a severe head cold, but initially, she didn’t notice.
“I’d be cooking, and my husband would say, ‘Can’t you smell that? That’s rotten. Do not eat that,’” she said. “I would just shoo him off and say, ‘It’s just you.’”
She realized how serious her smell loss was after she failed to notice a gas leak in a patient’s kitchen and later, a smoking dishwasher in her own home. Earlier this year, Turner took a chance and enrolled in the Wash U smell training study.
Turner said she first became aware of a change in her sense of smell after about two months of smell training.
“I was in the office, and a girl had some flowers on her desk,” she said. “I was like, ‘Oh, my goodness, I can smell the fragrance!’”
At least six other research studies, mostly in Europe, have reported significant improvements in patients’ ability to smell after olfactory training.
While it’s unclear how the smell training works from a neurological perspective, it appears to be connected to changes in brain connectivity. One study used magnetic resonance imaging (MRI) of patients’ brains before and after a 12-week training session. The images showed an increase in connections between odor-processing regions of the brain.
Both Weissmann and Turner underwent two MRI sessions to look for changes in their brain activity and connectivity.
The research remains ongoing, and for now, it’s difficult to draw any conclusions from such a small number of patients.
But Wash U medical resident and study author Pawina Jiramongkolchai said the training seems to affect the patients’ ability to recognize different groups of odors.
“It’s not necessarily that I can identify that a rose is a rose, but that I can distinguish that there are different smells in the air,” said Jiramongkolchai. “The beauty of a clinical study is you see things in real time. You can see how patients improve and you’re with them for that experience.”
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