Our friend Andrew holds the glass to his left nostril and covers the right with his hand, before inhaling deeply. The plan for making the most of DramFest (the country’s largest whisky festival), he says, is to “take a deep sniff, take a sip, then pour the rest out”. Otherwise you won’t remember which drams were any good.
Andrew’s curated three whiskies for us to try after dinner. They’re all good, but the last is a stunner from Scotland’s Campbeltown.
As I’m watching the demonstration, I’m reminded of something my now-retired colleague, John McDowall, once told me about. Nostrils.
Before I tell you about John’s particular nasal bugbear, let’s talk nose holes generally. Your nostrils are more than just two passive openings to your lungs. Obviously, they help us smell. The nasal epithelium, a patch of skin on the roof of our nasal cavity, is chock-full of olfactory sensory neurons – between 12 and 20 million neurons in fact, half for each nose hole.
Each one of those neurons has about 500 receptors that odour molecules can attach to as you breathe in. There are 172 families of olfactory receptors that work individually and in combination to send smell information to the brain for processing. That’s a wee bit more than there are licensed whisky distilleries in Scotland.
Your nose also stops environmental detritus from getting as far as your lungs. Cilia, the little hairs that line your nasal cavity, trap dust and small molecules in a layer of mucus and then “move” the undesirable material out of the nose. Our snot has a bad rep, but it’s mostly water, with a few proteins and antibacterial molecules for good measure.
Back to John, originally a Scotsman as it happens. John is a retired psychological sceptic. Well, he’s still a sceptic, but he’s also retired. In his time as a clinical psychologist then academic, he saw a lot of psychological fads come and go, and he was happy to be openly scathing when something stupid came along. For example, the claim that you can learn to activate your right or left hemisphere by practising breathing through one nostril.
There’s no reason to think this actually works, but it does hint at something I didn’t know until my wife and I did a bourbon tasting at Sazerac House in New Orleans. The excellent guide told us that our nostrils take turns throughout the day and, in spite of my own initial scepticism, he was right. At any one moment, one of your nostrils will be sucking in about three-quarters of the air you’re breathing. Unless you’re my wife, who has a perennially blocked left nostril.
This “nasal cycling” happens more or less frequently for different people but usually within a range of 30 minutes to six hours. We don’t notice this because we’re still getting as much air into our lungs, regardless of the dominant nostril.
Scientists aren’t sure why this alternating occurs. It may help to keep both nostrils optimally moist, the differential in airflow across the two may aid smell, or perhaps it’s just about giving one side a break to rest and recharge.
While the idea of activating your brain through breathing is controversial and associated with mixed evidence, you can influence which nostril is doing the work through posture, and the cycle can also change with age.
Final fun nose-hole fact for the day: did you know that you have a dominant nostril? Just as the majority of us have a dominant hand (and foot), most of us are left-nostril dominant. Why left? Because of lateralisation, and it’s tied to most of us being right-handed. In fact, this is a general psychophysiological rule – each hemisphere controls the opposite side of our bodies.
So, Andrew also needs to be wary of which nostril he’s poking into his dram.
