At the moment, there is no definitive diagnostic test for Parkinson's. Soon, this could change thanks to a woman named Joy Milne – she can smell brain disease on someone before symptoms appear.
It seems too bizarre to be true, but Joy noticed her husband's "musky" odor 10 years before he was diagnosed with Parkinson's by doctors. When he went to a meeting with other people with the condition, he realized that the smell and the disease were connected.
Since then, scientists have worked with Joy to try to identify what he was smelling exactly. Seems to be linked to sebum: the oily secretion that helps keep the skin and hair naturally hydrated and that can be produced more in people with Parkinson's.
While it was already known that Parkinson's leads to increased sebum production, the researchers wanted to know exactly which biomarkers were emitting the scent that Joy was collecting, so they used the chemical analysis of mass spectrometry to extract single compounds.
"We designed some experiments to simulate what Joy does, to use a mass spectrometer to do what Joy can do when she smells these things about people with Parkinson's," said one of the team, Barran Loss The University of Manchester in the United Kingdom the BBC.
Swabs were taken from 64 volunteers, some with Parkinson's disease and others without, to present "super smeller" Joy Milne for analysis. People with the disease have found more hippuric acid, eicosan, octadecanal and other biomarkers in their sebum.
The presence of these molecular compounds is linked to the changing levels of neurotransmitters in people with Parkinson's – those chemical messengers that help neurons connect and control our thoughts and movements.
"This could have a huge impact not only for the previous and conclusive diagnosis, but also to help patients monitor the effect of therapy," says Barran.
While 64 people are a relatively small sample, and it is not yet clear how early a sebum scent can detect Parkinson's, here is a lot of potential – if a swab test can be developed, it would be easy to take and relatively simple to analyze.
And even if there is still no cure for Parkinson's, the sooner the better – we could find out how to prevent Parkinson's before figuring out how to treat it when it gets to its last stages.
Most of us do not notice any change in the smell of people who have Parkinson's disease – scientists think a particularly acute sense of smell, like Joy's, is needed to capture the different smell.
In fact, Joy claims she can smell the scents of other diseases like Alzheimer's and cancer – so she's not finished helping the progress of science yet. Later he will work with the same team for a diagnostic test to detect tuberculosis.
More than 10 million people worldwide live with Parkinson's disease, a number that should grow rapidly in the future with the aging of the population. Thanks to Joy and the work of the researchers behind this new study, we may be able to do something about it.
"What we could hope for is whether we can diagnose people before, before the motor symptoms enter, that there will be treatments that can prevent the spread of the disease," Barran told the BBC. "So this is really the ultimate ambition."
The research was published in ACS Central Science.