WHEN Joy Milne鈥檚 husband Les started to give off a strange musky scent, she was none too happy. She has always had a keen sense of smell, and this was unmissable. 鈥淚t was almost like a slap in the face,鈥� she says. 鈥淚 didn鈥檛 like it.鈥�
Les was adamant he was looking after himself properly, and when no one else picked up on the smell, Joy let the matter lie. It was only 12 years later, when Les was diagnosed with 笔补谤办颈苍蝉辞苍鈥檚 disease, that she realised the magnitude of what she had noticed.
Joy, who lives in Perth, UK, is a super-smeller with an almost supernatural ability to sense odours that most people don鈥檛 perceive. Perhaps this is because she experiences synaesthesia, a neurological condition in which different kinds of sensory information become mixed-up. That means she can visualise the flow of smells and even experience them as sensations. 鈥淪ome smells make my back go cold,鈥� she says. She has to avoid the supermarket aisle with soaps and make-up because it is too overpowering.
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In the same way that a wine taster might train their nose to recognise the different aromas of the drink, she thinks that her work as a nurse attuned her sense of smell to different medical conditions. Now, retired after decades of vivid olfaction, her incredible nose is helping find new ways to diagnose diseases.
This unusual career path has its origins in 1994, when Les was diagnosed with 笔补谤办颈苍蝉辞苍鈥檚 disease aged only 45. This condition destroys dopamine-producing cells in the brain, leading to tremors and difficulty moving.
When the couple went to a support group for people with 笔补谤办颈苍蝉辞苍鈥檚, Joy noticed something strange: Les wasn鈥檛 the only one with the greasy smell. Everyone else with 笔补谤办颈苍蝉辞苍鈥檚 seemed to have it too. Under the pretext of handing out cups of tea, Joy took a few good sniffs to confirm her suspicions. She became convinced that the condition has a unique smell 鈥� the one that she had noticed on Les more than a decade earlier. 鈥淚 was smelling 笔补谤办颈苍蝉辞苍鈥檚 in the whole room,鈥� she says.
But as far as Les and Joy were aware, 笔补谤办颈苍蝉辞苍鈥檚 wasn鈥檛 known to have a distinctive odour. So when Joy met neurobiologist Tilo Kunath, who studies the condition at the University of Edinburgh, UK, she asked him about it. Kunath said there was nothing in the literature about a particular 笔补谤办颈苍蝉辞苍鈥檚 smell.
Kunath thought nothing more about Joy鈥檚 questions until a colleague suggested that her observation might be worth investigating. After all, cancer has an odour that can be detected by specially trained dogs. Why not other diseases too?
So Kunath got back in touch with Joy, and their conversation convinced him that she was on to something. He decided to put her skills to the test. She was given identical T-shirts to smell, and asked to determine which had been worn by people with 笔补谤办颈苍蝉辞苍鈥檚. She passed with flying colours 鈥� with one exception, where she identified one of the people who hadn鈥檛 been diagnosed with 笔补谤办颈苍蝉辞苍鈥檚 as having the disease.
Eight months later, the person Joy misidentified told Kunath he had been diagnosed with 笔补谤办颈苍蝉辞苍鈥檚. 鈥淲hen this false-positive turned out to be a true positive, that was a jaw-dropping moment. We couldn鈥檛 believe it,鈥� says Kunath. 鈥淛oy was telling us this person had 笔补谤办颈苍蝉辞苍鈥檚 before anyone knew.鈥� It seemed like Joy really did have the ability to sniff out the condition before the neurological symptoms arise.
That was potentially enormous news. As a rule, 笔补谤办颈苍蝉辞苍鈥檚 is diagnosed via symptoms such as tremors or movement difficulties, by which time irreversible brain damage has already occurred. 鈥淔ifty per cent of the neurons that make dopamine are usually lost by the time you get motor symptoms,鈥� says Kunath. While no drugs presently exist to prevent or cure the condition, some promising treatments are in the . If and when these are approved, early diagnostic tests will be vital.
To find the chemicals responsible for the 笔补谤办颈苍蝉辞苍鈥檚 odour, Kunath teamed up with analytical chemist Perdita Barran at the University of Manchester, UK. 鈥淲e want to find biomarkers that occur before the onset of the symptoms,鈥� says Barran. The researchers soon secured funding from the charity 笔补谤办颈苍蝉辞苍鈥檚 UK as well as the Michael J. Fox foundation.
They started by listening to Joy. She had identified the upper back as the area of the body with a particularly strong smell, so the researchers took swabs of this region from people with 笔补谤办颈苍蝉辞苍鈥檚 and analysed the volatile compounds they found there.
鈥淎lzheimer鈥檚 smells faintly of vanilla, whereas cancer has an earthy, vegetable smell鈥�
The preliminary results are promising. In November 2018, the team reported a number of biomarkers that seemed to differ between people who did and didn鈥檛 have the condition. 鈥淭here is a signature that looks significantly enriched in 笔补谤办颈苍蝉辞苍鈥檚 patients,鈥� says Kunath.
The real challenge, however, is to see whether this chemical signature can be detected on people who unknowingly have the condition but who currently show no symptoms, such as those with REM sleep disorders who have a high chance of developing 笔补谤办颈苍蝉辞苍鈥檚. The aim is to have a diagnostic test ready for when drugs to treat the condition become available.
Passing the smell test
Joy is involved in this research too 鈥� sniffing the compounds isolated from swab samples to evaluate whether they match the 笔补谤办颈苍蝉辞苍鈥檚 smell that she first identified on her husband.
But for Joy, 笔补谤办颈苍蝉辞苍鈥檚 is just the beginning. 鈥淎lmost every disease has a unique odour,鈥� she says. To her, Alzheimer鈥檚 smells faintly of vanilla, whereas cancer has an earthy, vegetable smell. So her remarkable abilities could allow for early detection of other diseases, too.
Last year, she visited Tanzania to help the charity APOPO, which trains African giant pouched rats to detect tuberculosis 鈥� another disease that is hard to diagnose but which, for Joy, has a particularly harsh smell. In Tanzania, she observed the rats smelling saliva samples from children with TB, giving pointers on the protocol and background scents in the working environment.
鈥淛oy can tell us things in a day, whereas a rat would take months,鈥� says APOPO鈥檚 CEO Christophe Cox. 鈥淪he could really speed up our work.鈥� Plans are afoot, too, for a project to diagnose TB from its smell, combining Joy鈥檚 olfactory talent with the analytical skills of Barran鈥檚 team in Manchester.
Joy is excited about her new career as a super-smeller, given its potential to help people identify and treat devastating conditions in their early stages. She finds solace in knowing that the breakthroughs her work might enable could give people like Les, who passed away in 2015, a better chance. 鈥淚t isn鈥檛 an easy thing to do, to sniff a disease. But it鈥檚 hard to watch the person you love being destroyed by something that no one can do anything about and I don鈥檛 want other families to suffer the way our family suffered,鈥� she says. 鈥淲e humans have turned our back on our sense of smell. We should be using it more.鈥�
Kunath agrees. 鈥淲e might just be touching the tip of the iceberg regarding what can be detected with odour.鈥�
