How many people's eating experience is being diminished as a consequence of long COVID? No one really knows.

We do know that many of those infected report loss of smell and taste – called anosmia – as a symptom (it is believed that 75-95% of what we taste is actually due to the smell). This can develop into parosmia: when the smell returns but is distorted. The smell and taste of certain things – or sometimes everything – is different, and usually unpleasant.

Parosmia is currently regarded as one of the symptoms of long COVID-19 syndrome or chronic COVID-19 syndrome. But the full extent of the problem is unclear. At the start of the year, the charity Fifth Sense reported that about 60% of those with COVID suffer smell and taste disturbances; of that 60%, about 10% have persistent problems beyond four weeks. Newer data from the Imperial College London-led REACT-2 study in June 2021 suggested that more than two million people in England may have been affected by persistent symptoms lasting for 12 weeks or more after COVID.

Many can shrug off smell and taste loss in less severe and short-lived cases. In others, it can greatly impact their enjoyment of food and life. Some experience nutrition problems by eating too little or too much (in an attempt to chase those lost flavours). There are implications for food safety too. A 2014 study found that people with anosmia were more than twice as likely to eat spoilt food.

Smell and taste: the ‘forgotten’ sense

Smell and taste disorders have always existed. But COVID put the problem firmly on the map. Speaking at a recent webinar organised by the Institute of Food Science and Technology, Dr Jane Parker from the Flavour Centre at the University of Reading, noted there was little awareness of olfactory dysfunction until COVID hit. She estimated it has since impacted a trillion olfactory sensory neurons across the globe.