Wine & Spirits - Spring 2022 - 16

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mell is a sense that we tend to take for granted. But its
loss can be devastating, and not only for those who use it professionally.
It adds a great deal of color to life, and those who have
become anosmic-the medical term for losing the ability to smell-frequently
report feeling depressed. The pleasure that comes from food
and drink is lost without smell-what we think of as " taste " is actually a
multimodal sensation that has a lot of input from smell, as well as from
taste itself, touch and vision. All the time, smell is there, working in the
background, and we often only notice its significance by being deprived
of it. There are also safety implications in not being able to smell food
that has gone off, or a gas leak, or smoke from an unintended fire.
HOW WIDESPREAD IS SMELL DYSFUNCTION?
from the relatively few surveys looking at its incidence, smell
loss-whether it is partial or complete-is more common than most
people realize. There are three terms that describe the different sorts
of damage to this sense. The first is anosmia, the loss of smell. Then
there's parosmia, which is a distorted sense of smell in the presence of
an odor source: things no longer smell the way we are used to them
smelling. Then there are phantosmias, which are smells in the absence
of an odor source.
Around one in 10,000 people are born without any sense of smell.
But it is much more common for people to lose this sense, either partially
or completely, through accident, disease and aging. Head trauma
is a common way for people to become anosmic, because the nerve cells
that detect smell molecules-called olfactory neurons-pass through
a structure called the cribiform plate in the skull, and a rapid jarring
of the head can cause these to shear off. Famously, in the wine world,
this happened to the UK wine merchant Harry Waugh. In a review by
researcher Thomas Hummel and colleagues, they found that the prevalence
of olfactory loss was reported as 22 percent in 25- to 75-year-olds
in one study, 19 percent in people over 20 years old in another, and 24
percent of those over 50 in a third. This isn't complete loss in all cases,
but rather a significant impairment. These figures are based on testing:
Studies that rely on self-reporting show lower figures, because many
people don't realize that they've lost a lot of function if this diminishment
in smell ability happens gradually.
What about the effect of aging? Back in 1984, a study by Richard
Doty and his colleagues examined 1,955 people aged between five and
99. The peak performance was between the ages of 30 and 50, and
declined markedly after the age of 70. After the age of 80, three-quarters
showed major impairment. Another study from 2002 looked at
2,491 people aged 53 to 97. Overall, 24.5 percent had impaired olfaction.
Of those over 80 years old, 62.5 percent had impairment. Interestingly,
the self-reported figure for impairment was 9.5 percent.
COVID-ASSOCIATED SMELL LOSS
though it took a while for smell loss to Be recognized as a common
symptom of COVID, we now know that around half of those with
COVID lose their sense of smell, while many others experience parosmia
or a degree of smell loss. The good news is that almost 90 percent
recover most of this function within four weeks. However, for a subset
of people, the news is less good: the dysfunction in smell is long-term.
This is an alarming prospect for anyone, but particularly for those who
use their sense of smell professionally. For many of the long-term smelldisturbed,
the loss is complete. For others, smell comes back after a
while but in a distorted form, where things don't smell the way they
should. This is also upsetting for those involved.
The mechanism behind COVID-induced smell loss isn't completely
clear, but a series of deductions have led scientists to think that the
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virus is affecting the sustentacular cells in the olfactory epithelium that
play a supporting role to the olfactory receptor cells, which themselves
are specialized neurons. The virus SARS-CoV-2 attacks cells by targeting
a receptor on their surface called ACE2, and the olfactory neurons
don't have these receptors, while sustentacular cells do.
As well as smell loss, COVID is also implicated in dysfunctions in
taste. This is a little complicated to separate out, though, because
infected people could lose their sense of smell and then report that
their " taste " (which is a combination of taste, smell and touch) is
impaired. It does seem to be a side-effect of COVID, although no one
has a handle on the mechanism yet.
WHY THIS IS CONCERNING
as a wine professional, i'm concerned aBout contracting covid
again. According to the statistics, there is a good chance that if I do, I
will experience some smell loss; I could also experience some loss of
taste. All of this is worrying because a lot of my work involves tasting,
describing and assessing wine. Aside from this, wine is my hobby, and
I derive a lot of pleasure from it-as do many of the readers of this
magazine, I would imagine. I was lucky last time: my sense of smell
returned to normal. But what if I were to be one of the unlucky ones
with long-term loss or disturbance? As COVID moves from pandemic
to endemic, we are being told that we have to live with this virus, and
treat it much like the flu-with the current restrictions aimed to limit
its spread removed. Those of us working as professionals where smell
is vital to our jobs will feel like we are now in a lottery situation: if our
number comes up, it's the end of our career.
PROSPECTS FOR RECOVERY
there is, however, a glimmer of hope. while smell loss is permanent
for some, it seems that for many there are things that can be done
to hasten the recovery of function. Smell turns out to be quite a malleable
sense. Our olfactory neurons are the only part of the nervous
system that is able to regenerate, and these cells regenerate every six
weeks or so. A clue that recovery of function is possible came from the
work of Charles Wysocki and colleagues, in 1989, on the way people
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