Detecting Illness Through Our Sense of Smell

Fagjun | Published 2018-01-24 23:16

Good or bad, the truth is that we all smell. It turns out, however, that our smell can also indicate if we’re sick, not just whether or not we remembered to shower that day.

Can we smell our illnesses? [Photo via Unilever]

Can we smell our illnesses? [Photo via Unilever]


Late last year, news broke about a woman who can identify a certain smell as indicative of Parkinson’s disease. Joy Milne was able to notice a change in her husband’s smell about 12 years before he was diagnosed with the condition, though she wasn’t able to immediately identify the connection between the two events. According to Joy, her husband Les had a “sort of woody, musky odour” that prompted Joy to question Les’s hygiene. Les, however, was certain that he was cleaning himself properly and didn’t notice anything different about the way he smelled.


Parkinson’s is notoriously difficult to diagnose, and many patients receive their diagnosis when the disease has already progressed. Joy Milne, however, would prove that all she needed to detect Parkinson’s may just be her sense of smell.

An Intriguing Experiment

Joy Milne and her late husband Les with their grandchild [Photo via Parkinson's UK/PA Wire]

Joy Milne and her late husband Les with their grandchild [Photo via Parkinson's UK/PA Wire]


About 17 years after Les’s diagnosis, researchers had Joy smell 12 shirts, six of which belonged to people without Parkinson’s and six that belonged to people without Parkinson’s. Joy detected the smell in seven—with the seventh shirt belonging to an individual who was diagnosed with the disease about eight months later.


While this experiment is intriguing, it’s still not completely convincing. Researchers are working on a way to conclusively determine if Parkinson’s does indeed have a smell. They’re also formulating a new smell test more rigorous that the one that Joy Milne underwent.


However, the idea that certain smells can be associated with certain diseases isn’t new or groundbreaking. For example, it’s known that diabetics produce fruity-smelling urine and breath. Those with cholera produce sweet-smelling stool, while those with arsenic poisoning produce a garlicky odor.


The question now may be why we smell differently when we’re sick. The reason is actually the same reason that we have odor at all. We always have an odor, quite literally oozing out of every pore on our skin. Our odor changes depending on factors like age, diet—and yes, health. Thus, when something in those factors changes, our odor may change as well. If we pay enough attention, any one of us can actually detect those changes.

Looking Into Matters

Our sense of smell has untapped potential.

Our sense of smell has untapped potential.


The research team working on the more rigorous Parkinson’s smell test is now working on the chemical identification of the molecules in the process. The team has also obtained over 800 sebum samples swabbed from volunteers. Preliminary tests have already shown that Parkinson’s disease patients have more elevated levels of some molecules. Researchers may be able to use these molecules as a diagnosis tool.


They also want to know whether or not Parkinson’s can be detected before the symptoms appear. It seems possible, since Milne was able to detect the smell years before her husband’s diagnosis. Then again, Milne by herself is a very small sample size, and more evidence is needed before researchers can say for certain that our sense of smell can indeed detect Parkinson’s.

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