How’s your sense of smell? In the recent – and ongoing – COVID crisis, our ability to smell (or not) has become one of the key indicators of whether we might have the virus. Indeed, the latest studies suggest that smell tests would be more effective than temperature tests in gaging who has and who hasn’t got COVID-19.
I lost my sense of smell back in April, when (like almost every Londoner I knew) I suspected I had the virus. Hour after hour I self-diagnosed on the NHS website, only to be told that I categorically didn’t have COVID. Daughter Number Three – who hopes to study medicine next year – stuck a branch of rosemary under my nose and, when I couldn’t smell a thing, shooed me back to bed.
Scientists have now worked out why so many (75% of those testing positive) lose their sense of smell with COVID. Apparently it’s not the olfactory neurons (smell cells) that are invaded and destroyed but a support system of cells. This is why we typically regain our sense of smell within a week. Scientists haven’t yet worked out why some people lose their ability to smell for much longer.
Unable to smell anything (a condition known as anosmia), I began to obsess about what it is to smell. I’ve always been a bit preoccupied with smells (one reader of my novels once asked why every location had a smell), but losing the ability to decipher odours took my preoccupation to a new level. Smell is our constant, unacknowledged companion, an underrated miracle, the Cinderella of the five senses (until now, that is). It’s the only sense that goes direct to the emotional and memory centres of the brain. All other senses pass through a brain-part called the thalamus – a sort of processing switchboard which orders and files our experiences. Which might explain why certain smells can trigger such powerful and evocative memories.
Recently scientists have found smell receptors in other body-parts, from skin and blood to intestines and lungs, leading to speculation that our smell receptors could be responsible for much more than detecting odours, like triggering the release of chemical messengers to ensure we create new cells or neurons (for instance).
We know that our sense of smell can fade as we age (many dementia sufferers lose their sense of smell and taste altogether, and loss of smell is often a sign of early cognitive decline, particularly in diabetics) putting us at risk of all sorts of things – smell is our early detection system for a range of dangers, from smelling fire or a gas leak to identifying rotten food.
But smell is also a source of profound pleasure, from the garlic-herb laden smell of cooking to the smell of damp forest to the smell of flowers. When we lose our sense of smell we lose a little bit of ourselves, and reading written accounts of people learning to live without any smell at all is sobering, sometimes heart-breaking. Here at the Age-Well Project we’re not just about surviving. In fact we’re more interested in thriving – enjoying full and curious lives for as long as we can. That means being able to smell the food we’re cooking, the plants we’re growing and the air we’re breathing.
A study out last week rather startled me. Researchers found that mice fed a moderately fatty, high-sugar diet (a mouse version of the Standard American Diet apparently) showed a more rapid decline in their ability to learn and remember smells. The researchers believe excessive sugar may be the culprit, somehow causing the olfactory sense to deteriorate.
In a normally healthy person, smell cells are remarkably resilient, as plastic as brain cells. They renew themselves every four to six weeks. Some experts describe our sense of smell as another muscle – use it or lose it. This becomes more important as we age. Because by the time we reach 75, 80% of us will have an impaired sense of smell.
But we don’t have to lose our ability to smell… It appears that we need the stimulation of smell, not only to improve our smell cells but to preserve them in the first place: studies show that rats confined to an odour-free environment lose their ability to smell, only regaining it when they return to an environment rich in odours.
In other words, start sniffing and smelling. I was lucky enough to smell-walk with odour expert, Dr Kate McLean, a week before lockdown. Together we sniffed our way around a south-of-England town, with Kate explaining why our ability to keep smelling is so important. She also explained why tulips no longer smell. The scent has been bred out of them because supermarkets want long shelf life and we – the purchasers – prefer blowsy good looks to perfume. So if we lose our sense of smell it’s (partly) our own fault! And another reason to grow our own (perfumed) flowers, perhaps.
We can still work our smell-muscle in the kitchen. I’ve been repeat-cooking one of my favourite recipes on this site, Italian bean stew, just to flood the house with its pungent, earthy aroma.
If you’ve lost your sense of smell, or not managed to regain it post-COVID, you can do an organised programme of smell-training here .
To learn more about Dr McLean’s smell-walks and works, visit her site here.
I’ll be writing about the therapeutic power of certain scents and smells in a future post. In the meantime, lockdown is a perfect opportunity to practise your smelling!
Fiona Hepden says
Thank you for writing about one of the long term impacts of Covid19, anosmia.
I had what I assumed was a mild bug at the end of February, and have subsequently realised it was COVID. I lost my sense of smell and taste, and despite starting smell training in March as suggested by Abscent, and also having sessions of specific acupuncture (identified by some as helpful) I still only have a very limited sense of both taste and smell.
There is a Facebook group for fellow sufferers ‘Covid19 smell and taste loss’ which offers links to various research projects, surveys as well as peer support for fellow sufferers.
This is a long term condition, which is affecting thousands of people, and as yet is receiving little acknowledgement from the press and medical profession, despite the significant impact it is having on some sufferers mental health.
Thanks again for raising the issue.
Annabel Streets says
Thanks for sharing this, Fiona. I’m so sorry to hear that you’ve not regained your sense of smell or taste yet. Medics here were very slow to acknowledge or recognise the loss-of-smell symptom, but it’s getting a little more publicity now – fortunately. I have my fingers crossed for you!
Marion Kealy says
My husband lost his sense of smell sometime before he showed signs of Dementia. He loved lots of sugary things, sweets, cake etc. He was also a very enthusiastic amateur footballer in the days of the hard leather footballs, and he was a ‘header’ of the ball. I think these all contributed to his dementia.
Annabel Streets says
I’m sorry to hear that, but yes, head injuries have been extensively investigated with disturbing results. I’m always horrified when I see footballers heading the ball – it’s more-or-less proven… sadly. Thanks for the comment, Marion.
Annie Harris says
I have so enjoyed reading this this morning – i am following a week-long program of study looking at the beneficial actions of a few distinct herbs, (rose, lemon balm, chamomile, mint and lavender so far), and so have enjoyed great olfactory meditations, and this seems another valediction.
Annabel Streets says
That sounds divine – what course is it?
Hi Annabel, thank you for another interesting read. At my school there was a double-sided path of rosemary at the front, and every morning and afternoon I used to run my hand along the top of the hedge. Such memories – as you can imagine, since I loved school.
I believe that it is possible as you get older to lose and regain your sense of smell. I remember walking with my daughter, smelling the roses in the gardens, but having to ask her if they smelt at all. I’m fine now!
It is difficult to describe a perfume because we just dont have enough words in the English language. I wonder if any language does.
I know what you mean about gardeners preferring blowsy colours and perfume being “bred out” of some species. Sweet peas and freesias are others like tulips and I refuse to buy seeds/corms that don’t advertise “strong perfume”.
Your perfume tour sounds divine (oops I used the same word as you – sorry) and I am going out right now to see if I can find a bit of mint in the garden.
I will try your recipe soon too, as soon as I can get some beans.
Annabel Streets says
Thank you for your lovely comment, Gaynor. I too always run my hand through (usually other people’s) bushes of lavender, rosemary, mint – anything really. Such wonderful perfumes and always so uplifting – astonishing really, the incredible power of smell. So good to know it comes and goes and comes back again. I shall be looking out for ‘strongly perfumed’ seeds too…