New research shows support for Covid-19 recovery

The effectiveness of smell training has been researched and documented formore than 10 years now. We have evidence to demonstrate that it is effective in helping people recover from persistent smell loss after a cold or other virus.

On this evidence, doctors were comfortable with recommending smell training for patients who lost their sense of smell following Covid-19 infection. But with all things medical, we can’t be certain until the hypothesis has been tested scientifically.

Now, thanks to Dr Atılay Yaylacı and his team at the Faculty of Medicine at Kocaeli University in Turkey, we have evidence that olfactory (smell) training appears to improve the sense of smell in patients with lost or altered smell following Covid-19.

The study led by Dr Yaylaci tested a group of people with post–Covid smell loss using ‘classical olfactory training’ and compared them with a control group who did not do any olfactory training. The group who followed smell training for 12 weeks all showed a significant improvement in their ability to smell. Only 78 percent of people who didn’t do any training (the control group) showed some improvement, and 22 percent of the control group found their sense of smell got worse.

What is classical olfactory training?

The study was designed using classical olfactory training (COT). Professor Thomas Hummel et al. first described a structured method for smell training using concentrations of four odours (rose, eucalyptus, lemon, and cloves), which is now called ‘classical olfactory training’ (COT). They reported the benefit of COT over 12 weeks in the treatment of olfactory disorders from various causes. The AbScent Original Smell Training kit is designed on the principles used by Professor Hummel and is suitable for classical olfactory training.

What is modified olfactory training?

Since the original study, there have been several other studies looking at the difference that using different types and numbers of odours could make to effective olfactory training. In particular, the work published by Dr Aytag Altundag and team in 2015 found that continuing smell training using four different odours after the 12th week, and four more odours after the 24th week produced better results compared to using the same four odours throughout the entire study.

This practice is referred to as ‘modified olfactory training’. Some people think this boost to the efficacy of smell training comes from the change to different odours. Others think that smell training is more interesting to do if there are new odours and therefore people are more happy to keep the training going.

Which is the best olfactory training for me?

If you have lost or altered smell – olfactory dysfunction – as a result of Covid-19 or another virus, smell training in any form is likely to help. For most causes of smell loss where the patient still has the functional ability to smell, olfactory training has been found to be effective. Keeping up a daily practice is the most important factor so it’s important to train with odours that you enjoy using and find ways to keep the motivation up. Exploring the encouraging results of some of the studies on our research pages might be just the boost you need to keep going.

Read the full published article:

Yaylacı A, Azak E, Önal A, Aktürk DR, Karadenizli A. Effects of classical olfactory training in patients with COVID-19-related persistent loss of smell. Eur Arch Otorhinolaryngol. 2022 Jul 29:1–7. doi: 10.1007/s00405-022-07570-w. Epub ahead of print. PMID: 35904631; PMCID: PMC9335450.

The article about Modifed Olfactory training is: 

Altundag A, Cayonu M, Kayabasoglu G, Salihoglu M, Tekeli H, Saglam O, Hummel T. Modified olfactory training in patients with post-infectious olfactory loss  Laryngoscope. 2015 Aug;125(8):1763-6. doi: 10.1002/lary.25245. Epub 2015 Jun 2. 

September 01, 2022