Elliott & Thompson
EARLY in the covid-19 pandemic, London-based reporter Paola Totaro lost her sense of smell. Feeling trapped in a sensory void, she began investigating the mysteries of smell, and the result is the engaging and timely On the Scent, written with her husband, journalist Robert Wainwright.
The pandemic has put a spotlight on olfactory impairment. The coronavirus has affected millions of people鈥檚 ability to smell, and the symptom has persisted in some, months after the infection has passed. Anosmia is the clinical term for an inability to perceive smell. Parosmia turns pleasant smells into stenches for some (the 鈥渇ortunate鈥� ones perceive foul smells as pleasant). In phantosmia, people hallucinate smells.
Totaro鈥檚 personal experience and the authors鈥� sensitive profiles of people with anosmia or parosmia make it clear that a sense of smell can be integral to emotional well-being. Depression, the authors discover, affects a good third of those who have lost their ability to smell. Neuroscientist Oliver Sacks has previously written of 鈥渁 woman transfixed by grief when she couldn鈥檛 recognise the smell of her own baby鈥�.
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Smell is the least studied of our senses. The authors introduce us to the work of pioneering olfactory researchers such as Linda Buck, who identified the family of genes that allow humans to detect and distinguish smells. Buck鈥檚 fundamental research, for which she won a , has laid the groundwork for understanding certain diseases characterised by anosmia.
Gathering evidence shows that conditions like Alzheimer鈥檚 and Parkinson鈥檚 are associated with an early loss of smell. A dysfunctional sense of smell is also linked with schizophrenia and dystonia. So, in the future, a smell test may be part of routine health check-ups, particularly for older people.
Researchers have found some of the biological mechanisms that lead to covid-19-related smell loss. The virus doesn鈥檛 infect odour-detecting nerve cells, but attacks cells that play a supporting role in the olfactory system 鈥� so regeneration is a possibility.
But no doctor can tell you how long you will be without smell, or even if you will regain it. Though there is no cure for anosmia, a technique known as smell training 鈥� regular sniffing of aromas such as rose and lemon 鈥� has helped some people with acquired olfactory loss. Patience is key, the authors stress.
On a recent trip to Puglia, Italy, Totaro saw a religious procession where a parishioner was carrying an incense burner. The scent of frankincense and myrrh brought back memories of attending mass with her grandmother 鈥� and she wept in gratitude for her newly functioning nose.
