VITAMIN A could one day cure long-term loss of smell caused by coronavirus, scientists hope.
Long-haulers can suffer with the persistent symptom for months on end, with some reporting that it has ruined their life.
The Apollo trial will see if vitamin A – abundant in carrots, oranges mangos, eggs and cheese – can help that.
People in the small study will be given nasal drops containing the vitamin for 12 weeks, the University of East Anglia (UEA) said in a statement.
The university said research from Germany had shown the potential benefit of the vitamin, and its team “will explore how this treatment works to help repair tissues in the nose damaged by viruses”.
Vitamin A is most commonly known for keeping eyesight in prime condition – hence why you are told to eat carrots to “see in the dark”.
But it’s also vital for the body’s immune system to work properly, as well as keep skin and the lining of some parts of the body, such as the nose, healthy.
The researchers hope the study “could one day help improve the lives of millions around the world who suffer from smell loss, by returning their fifth sense”.
The coronavirus and other colds can cause loss/change of smell, called anosmia, for at least one in ten sufferers.
Sometimes this won’t go away, or long Covid patients can end up with parosmia – when the smell of things get confused in the brain, for example coffee ends up smelling like car fumes.
People who are suffering and keen to participate in the new trial are asked to seek a referral from their GP to the Smell and Taste Clinic at the James Paget Hospital in Norfolk’s Great Yarmouth.
The study, which is being funded by the National Institute for Health Research, will begin recruiting participants in December.
Typically “smell training” is recommended, which involves smelling different jars of essential oils and thinking hard about the plant they are obtained from.
The NHS says treating the root cause can sometimes help, for example steroid nasal sprays or drops for sinusitis or nasal polyps.
However, it comes as a study by an international group of smell experts advised against using steroids to treat smell loss and instead suggested smell training.
One of the researchers, Prof Carl Philpott of UEA, said there was “very little evidence” steroids will help with smell loss.
They have “potential side effects including fluid retention, high blood pressure, and problems with mood swings and behaviour”, he said.
Instead, the scientists recommended those who have experienced smell loss sniff at least four different odours, twice daily for several months.
Prof Philpott said the method “aims to help recovery based on neuroplasticity – the brain’s ability to reorganise itself to compensate for a change or injury”.