A Lost Sense Of Smell

The rich, earthy smell of freshly ground coffee on a crisp winter morning. The bright fragrance of a glass of orange juice, or the heady aroma of an uncorked bottle of shiraz. The over-the-top scented assault of lavender vanilla hand soap, or the utterly clean whiff of a freshly laundered bath towel. The smell of wood smoke from a neighbor’s chimney. These are little things that add color and flavor to our lives and that people with working noses take for granted.

But among us are people who have been infected with COVID who have lost their sense of smell. A year into the epidemic, many of us know people who have survived their bout with the coronavirus, and they often report that the strangest symptom of the disease–and the one that made them realize they’ve got the ‘rona in the first place–is the sudden absence of smells in their world. And the loss of the sense of smell (called anosmia) also can produce a lost sense of taste (called dysgeusia), which means victims of the virus may lose two of their familiar senses at the same time. And some unfortunate victims of the disease develop parosmia, in which the ability to detect smells gets scrambled, so that a flower might smell like an open sewer.

For some victims, the sense of smell comes back quickly as they recuperate from their exposure, but for others the anosmia or parosmia lingers on and on. You can get a sense of the extent of that problem by running searches on regaining sense of smell, which produces lots of hits. Doctors and hospitals have featured links on Google about the condition and their treatments, and there are first-person accounts about the battle to get the olfactory senses working again. The Los Angeles Times recently ran an article that described the sweeping range of potential treatments that people who are desperate to return to normal can try — which might include CAT scans, steroids, and aromatherapy. And the LA Times piece indicates that some victims will try just about anything.

Those of us who have dodged the COVID bullet can’t really imagine what this condition is like, and I certainly hope that I never find out through personal experience. But it’s also a reminder that, when victory is declared in the war on the coronavirus, there will still be people out there suffering from its after-effects, and wondering if their world will ever get back to the way it was before the pandemic hit.

Smelling One Trillion Smells

A study recently estimated that human beings can detect 1 trillion different smells. At least half of those smells apparently are found somewhere in the average high school boys’ locker room. (Just kidding!)

In the study, the researchers mixed different “odorant” molecules in combinations, provided participants with three vials of scents, and asked them to identify the outlier in the group. The participants were, on average, adept at distinguishing between the different smells. The researchers then multiplied the different combinations to come up with their estimate of one trillion. Believe it or not, one of the researchers is convinced that the estimate of one trillion — 1,000,000,000,000 — is almost certainly too low.

One trillion is a lot of smells, but the conclusion is plausible from an evolutionary standpoint. The researchers believe the odor-detection capabilities are directly related to the hunter-gatherer history of homo sapiens, because our distant ancestors relied on their sense of smell as a key component in their ability to track prey, sense enemies, determine whether food remained edible and water was potable, and otherwise detect danger. If you couldn’t smell a silently approaching saber-tooth tiger and skedaddle, or make a judgment that the fly-blown piece of woolly mammoth haunch that you were planning on eating for lunch remained edible, you weren’t likely to survive to reproduce.

The recent study joins other studies that indicate that human senses are remarkably discriminating. Along with the ability to use our olfactory capabilities to detect one trillion smells, other studies conclude that the human eye can distinguish between several million shades of color, and the human ear can discern 340,000 different sounds. Talk about sensory overload!