During the pandemic, a lost sense of smell was quickly identified as one of the key symptoms of COVID. Nearly four years later, one in five people in the UK is living with a decreased or distorted sense of smell, and one in twenty have anosmia – the total loss of the ability to perceive any odours at all. Smell training is one of the few treatment options for recovering a lost sense of smell – but can we make it more effective?

Smell training is a therapy that is recommended by experts for recovering a lost sense of smell. It is a simple process that involves sniffing a set of different odours – usually essential oils, or herbs and spices – every day.

The olfactory system has a unique ability to regenerate sensory neurons (nerve cells). So, just like physiotherapy where exercise helps to restore movement and function following an injury, repeated exposure to odours helps to recover the sense of smell following an infection, or other cause of smell loss (for example, traumatic head injury).

Several studies have demonstrated the effectiveness of smell training under laboratory conditions. But recent findings have suggested that the real-world results might be disappointing.

One reason for this is that smell training is a long-term therapy. It can take months before patients detect anything, and some people may not get any benefit at all.

In one study, researchers found that after three months of smell training, participation dropped to 88%, and further declined to 56% after six months. The reason given was that these people did not feel as though they noticed any improvement in their ability to smell.

Cross-modal associations

To remedy this, researchers are now investigating how smell training can be improved. One interesting idea is that information from our other senses, or “cross-modal associations”, can be applied to smell training to promote odour perception and improve the results.

Cross-modal associations are described as the tendency for sensory cues from different sensory systems to be matched. For example, brightness tends to be associated with loudness. Pitch is related to size. Colours are linked to temperature, and softness is matched with round shapes, while spiky shapes feel more rough. In previous studies, these associations have been shown to have a considerable influence on how sensory information is processed. Especially when it comes to olfaction.

Recent research has shown that the sense of smell is influenced by a combination of different sensory inputs – not just odours. Sensory cues such as colour, shape, and pitch are believed to play a role in the ability to correctly identify and name odours, and can influence perceptions of odour pleasantness and intensity.

In one study, participants were asked to complete a test that measured their ability to discriminate between different odours while they were presented with the colour red or yellow, an outline drawing of a strawberry or a lemon, or a combination of these colours and shapes. The results suggested that corresponding odour and colour associations (for example, the colour red and strawberry) were linked to increased olfactory performance compared with odours and colours that were not associated (for example, the colour yellow and strawberry).

While projects focusing on harnessing these cross-modal associations to improve treatments for smell loss are underway, research has already started to deliver some promising results.

In a recent study that aimed to investigate whether the effects of smell training could be improved with the addition of cross-modal associations, participants watched a guidance video containing sounds that matched the odours that they were training with. The results suggest that cross-modal interactions plus smell training improved olfactory function compared to smell training alone.

The results reported in recent studies have been promising and offer new insights into the field of olfactory science. It is hoped that this will soon lead to the development of more effective treatment options for smell recovery.

In the meantime, smell training is one of the best things you can do for a lost sense of smell, so patients are encouraged to stick with it so that they give themselves the best chance at recovery.

Emily Spencer, PhD Candidate, Olfaction, Edinburgh Napier University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

The assertion from Queensland’s chief health officer John Gerrard that it’s time to stop using the term “long COVID” has made waves in Australian and international media over recent days.

Gerrard’s comments were related to new research from his team finding long-term symptoms of COVID are similar to the ongoing symptoms following other viral infections.

But there are limitations in this research, and problems with Gerrard’s argument we should drop the term “long COVID”. Here’s why.

A bit about the research

The study involved texting a survey to 5,112 Queensland adults who had experienced respiratory symptoms and had sought a PCR test in 2022. Respondents were contacted 12 months after the PCR test. Some had tested positive to COVID, while others had tested positive to influenza or had not tested positive to either disease.

Survey respondents were asked if they had experienced ongoing symptoms or any functional impairment over the previous year.

The study found people with respiratory symptoms can suffer long-term symptoms and impairment, regardless of whether they had COVID, influenza or another respiratory disease. These symptoms are often referred to as “post-viral”, as they linger after a viral infection.

Gerrard’s research will be presented in April at the European Congress of Clinical Microbiology and Infectious Diseases. It hasn’t been published in a peer-reviewed journal.

After the research was publicised last Friday, some experts highlighted flaws in the study design. For example, Steven Faux, a long COVID clinician interviewed on ABC’s television news, said the study excluded people who were hospitalised with COVID (therefore leaving out people who had the most severe symptoms). He also noted differing levels of vaccination against COVID and influenza may have influenced the findings.

In addition, Faux pointed out the survey would have excluded many older people who may not use smartphones.

The authors of the research have acknowledged some of these and other limitations in their study.

Ditching the term ‘long COVID’

Based on the research findings, Gerrard said in a press release:

We believe it is time to stop using terms like ‘long COVID’. They wrongly imply there is something unique and exceptional about longer term symptoms associated with this virus. This terminology can cause unnecessary fear, and in some cases, hypervigilance to longer symptoms that can impede recovery.

But Gerrard and his team’s findings cannot substantiate these assertions. Their survey only documented symptoms and impairment after respiratory infections. It didn’t ask people how fearful they were, or whether a term such as long COVID made them especially vigilant, for example.

In discussing Gerrard’s conclusions about the terminology, Faux noted that even if only 3% of people develop long COVID (the survey found 3% of people had functional limitations after a year), this would equate to some 150,000 Queenslanders with the condition. He said:

To suggest that by not calling it long COVID you would be […] somehow helping those people not to focus on their symptoms is a curious conclusion from that study.

Another clinician and researcher, Philip Britton, criticised Gerrard’s conclusion about the language as “overstated and potentially unhelpful”. He noted the term “long COVID” is recognised by the World Health Organization as a valid description of the condition.

A cruel irony

An ever-growing body of research continues to show how COVID can cause harm to the body across organ systems and cells.

We know from the experiences shared by people with long COVID that the condition can be highly disabling, preventing them from engaging in study or paid work. It can also harm relationships with their friends, family members, and even their partners.

Despite all this, people with long COVID have often felt gaslit and unheard. When seeking treatment from health-care professionals, many people with long COVID report they have been dismissed or turned away.

Last Friday – the day Gerrard’s comments were made public – was actually International Long COVID Awareness Day, organised by activists to draw attention to the condition.

The response from people with long COVID was immediate. They shared their anger on social media about Gerrard’s comments, especially their timing, on a day designed to generate greater recognition for their illness.

Since the start of the COVID pandemic, patient communities have fought for recognition of the long-term symptoms many people faced.

The term “long COVID” was in fact coined by people suffering persistent symptoms after a COVID infection, who were seeking words to describe what they were going through.

The role people with long COVID have played in defining their condition and bringing medical and public attention to it demonstrates the possibilities of patient-led expertise. For decades, people with invisible or “silent” conditions such as ME/CFS (myalgic encephalomyelitis/chronic fatigue syndrome) have had to fight ignorance from health-care professionals and stigma from others in their lives. They have often been told their disabling symptoms are psychosomatic.

Gerrard’s comments, and the media’s amplification of them, repudiates the term “long COVID” that community members have chosen to give their condition an identity and support each other. This is likely to cause distress and exacerbate feelings of abandonment.

Terminology matters

The words we use to describe illnesses and conditions are incredibly powerful. Naming a new condition is a step towards better recognition of people’s suffering, and hopefully, better diagnosis, health care, treatment and acceptance by others.

The term “long COVID” provides an easily understandable label to convey patients’ experiences to others. It is well known to the public. It has been routinely used in news media reporting and and in many reputable medical journal articles.

Most importantly, scrapping the label would further marginalise a large group of people with a chronic illness who have often been left to struggle behind closed doors.

Deborah Lupton, SHARP Professor, Vitalities Lab, Centre for Social Research in Health and Social Policy Centre, and the ARC Centre of Excellence for Automated Decision-Making and Society, UNSW Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.