For the many Covid-19 patients who have lost all or some of their sense of smell, doctors recommend an olfactory version of physical therapy called smell training. It is a way for the nose to relearn the connection to the brain, and also a way for patients to connect with food again.
Smell training may sound like some sort of punishment. As described here on Sniffly, smell training is a medically approved method of retraining the sense of smell for those whose senses have been damaged by disease or injury. Smell training is like weightlifting for the brain, it makes your brain stronger and fosters the production of new neurons.
What is modified smell training?
Modified smell training is a newer form of smell/olfaction therapy that uses 8-12 essential oils instead of the recommended 4 (clove, eucalyptus, lemon, rose). The point of smell therapy is to make you connect scents with memories. By adding more oils, we are increasing the number of scents we are using to make our brain work harder to remember something, which will increase the chances of it being able to trigger a memory.
Does modified smell training offer better results?
Most notably in 2015, a clinical study by Professor Hummel experimented with modified smell training across 85 participants that lost their smell following a viral infection. The participants were split into three groups. The first group conducted their smell therapy with 12 different odors, the second group use 4 odors (classical smell training), and the final group did not smell training at all.
Both of the groups that smell trained had improved results compared to the control group (that did not smell train). After the 12th and 24th weeks of smell therapy, participants that used modified smell training experienced better results than both groups.
Another ear, nose and throat specialist, Leigh Sowerby based in London Ontario, has also noted improvements in patients following modified smell training.
How to do modified smell training
The 2015 study by Professor Hummel used a wider range of odors consisting of menthol, thyme, tangerine, jasmine, green tea, rosemary, bergamot, gardenia, clove, eucalyptus, lemon and rose.
In Hummel’s study, patients smell training twice daily, for a period of 12-24 weeks. Clinicians recommend daily smell training as more frequent sessions will accelerate the rate of recovery.
As well, modified smell training is only effective once you’re able to detect some sense of smell from the four base scents (clove, eucalyptus, lemon, and rose).