Researchers at the University of East Anglia and James Paget University Hospital are launching a new project to see whether Vitamin A could help people regain their sense of smell after viral infections including Covid-19.
Smell loss is a common symptom of Covid-19, but even before Covid, many viruses had been causing smell loss and distortion and while most people naturally regain their sense of smell within a couple of weeks, many have been left with on-going smell disorders.
Previous research from Germany has shown the potential benefit of Vitamin-A, and the UEA team will explore how this treatment works to help repair tissues in the nose damaged by viruses.
They hope that the study, which has been funded by the National Institute for Health Research (NIHR), could one-day help improve the lives of millions around the world who suffer from smell loss, by returning their fifth sense.
Smell loss expert Prof Carl Philpott from UEA’s Norwich Medical School and James Paget University Hospitals NHS Trust, said: “The huge rise in smell loss caused by Covid-19 has created an unprecedented worldwide demand for treatment.
“Even before the Covid-19 pandemic hit, smell loss was thought to affect an estimated five per cent of people, with viruses accounting for 1 in 10 of those.
“And around one in ten people who experience smell loss as a result of Covid-19 report that their sense of smell has not returned to normal four weeks after falling ill.
“It’s a big problem, and our previous research has shown the impact of smell loss – including depression, anxiety and isolation, as well as risk of danger from hazards such as gas and spoiled food, and changes in weight due to reduced appetite.
“A key problem for patients and their clinicians is the lack of proven effective treatments.
“A recent study from Germany showed that people treated with vitamin A nasal drops improved twice as much as those in the untreated group.
“We want to find out whether there is an increase in the size and activity of damaged smell pathways in patients’ brains when they are treated with vitamin A nasal drops. “This would show recovery of the damage caused by common viral infections, including Covid-19, in the nose.”
The research team will work with patients who have lost their sense of smell due to a viral infection.
They will either receive a 12-week course of nasal vitamin A drops or inactive equivalent drops, and have their brains scanned before and after the treatment. The scans will be compared to those of a control group who have not been treated with vitamin A drops.
Prof Philpott said: “The patients will be smelling distinctive odours - roses and rotten eggs - while special MRI brain scans are taken.
“We will look for changes in the size of the olfactory bulb - an area above the nose where the smell nerves join together and connect to the brain.
“We will also look at activity in areas of the brain linked to recognising smells,” he added.
Duncan Boak, Founder and Chair of Fifth Sense, said: “At Fifth Sense we have engaged with thousands of people who have experienced changes in their ability to smell or taste as a result of the Covid 19 virus. They join an already large community of people with a smell disorder that pre-dates the pandemic.
“The question we are most often asked is about available treatments to support recovery. Not being able to smell is not only physically distressing but can affect the enjoyment of social occasions and present hazards and risks that might never have been previously considered such as not being able to detect gas leaks or spoiled food.
“Research into potentially successful interventions is vital to help people feeling the impact of smell disorders that affects the quality and enjoyment of their life.”
To take part in this trial, patients need to be referred to The Smell and Taste Clinic at the James Paget University Hospital by their GP. Recruitment is expected to begin in December 2021.
The NIHR is the largest funder of research in the country, and is the research partner of the NHS and social care. To find out more about other NIHR research happening near you, visit www.bepartofresearch.uk.