Why honing your sense of smell could keep you sharp as you age

I am not normally a fan of lotions and potions, but right now, four small vials sit on my bedside table.  

Every morning and every night, I open and sniff each one in turn, savouring the scents as they hit my nostrils. First, the sharp tang of lemon, followed by the abrasive chill of eucalyptus, the sweetness of rose and the metallic warmth of clove.  

My new routine – training what is, for most of us, a neglected sense – was inspired by some striking research linking our noses’ sensitivity to our cognitive performance. For one thing, studies have shown that the worse your sense of smell is, the worse you perform in cognitive assessments. Olfactory dysfunction has also been linked to more than 100 conditions, including ALS (motor neurone disease), multiple sclerosis, Parkinson’s disease, Alzheimer’s disease and general age-related cognitive impairment.  

And though some of that olfactory impairment is undoubtedly the result of neurological damage, more recent research suggests that smell loss could actually contribute to some conditions. Failing the sniff test may even limit our overall lifespan – a frightening thought, given how many people lost their sense of smell as a result of the covid-19 pandemic. 

“By middle age, your all-cause mortality can be predicted by your olfactory ability,” says Michael Leon, a neurobiologist at the University of California, Irvine.

Evidence like that has prompted a host of investigations into whether “smell training” can reawaken this often-ignored sense and sharpen our minds. So far, research and real-world experience suggest that it can.…