‘Super smeller’ research moves us closer to a diagnostic test for Parkinson’s

Researchers have identified small molecules secreted by the skin that are maybe responsible for a unique scent in people with Parkinson's.

Scientists at the University of Manchester have increased our understanding of how one lady can "smell" Parkinson's. The research, published in ACS Central Science and co-funded by Parkinson's UK, found several chemicals on the skin of people with Parkinson's that were uniquely associated with the condition.

It's hoped that these results could lead to the development of an early diagnostic test for the condition.

Chemical analysis

Professor Perdita Barran, an expert in chemical analysis from the University of Manchester, developed a system to screen for molecules specifically found on the skin of people with Parkinson's.

A waxy fluid on the skin, known as sebum, was swabbed from 43 people with, and 21 people without Parkinson's. The samples were then analysed using a technique called mass spectrometry to identify the molecules that cause the unique scent associated with Parkinson's.

'Smelling' Parkinson's

There is still no definitive diagnostic test for Parkinson's. This means confirming someone has the condition can take some time. 

It's thought that if different chemicals are present on the skin in people with Parkinson's, they could act as biomarkers – tiny changes in the body that can be measured to diagnose or monitor the condition.

The idea of being able to smell if someone has Parkinson's was first raised by "super smeller" Joy Milne. She noticed that people with Parkinson's had a distinct smell, which changed intensity as the condition progressed. Joy first noticed this in her husband Les, 6 years before he was clinically diagnosed with Parkinson's.

When put to the test by researchers in Edinburgh, she correctly identified which T-shirts were worn by people with Parkinson's and which ones weren't. In this new study, she worked alongside researchers in Manchester to pin down exactly what causes this unique scent.

An exciting discovery

The researchers found 4 molecules that were present at different levels in the sebum of people with Parkinson's, compared with people without the condition. The odour produced by these chemicals were confirmed by Joy as having a Parkinson's-like smell.

Now the molecules underlying the unique Parkinson's smell have been identified, the researchers hope to develop this into a diagnostic test.

Professor David Dexter, Deputy Director of Research at Parkinson's UK, said:

"Finding changes in the oils of the skin in Parkinson's is an exciting discovery that was sparked by a simple conversation between a member of the public and a researcher.

"More research is needed to find out at what stage a skin test could detect Parkinson's, or whether it also occurs in other Parkinson's related disorders, but the results so far hold real potential to change the way we diagnose the condition and may even help in the development of new and better treatments for the 145,000 people living with Parkinson's in the UK." 

Find out more

Read more about the search for biomarkers on our research blog, and how they can help speed up diagnosis.