Nearly 10 million people worldwide live with Parkinson's disease. While Parkinson's is incurable, some of its worst symptoms(症状) can be relieved and controlled using medications. A major problem of getting effective treatment at the right time is identifying the disease soon enough, before patients experience the symptoms brought on by irreversible neuron loss(不可逆转的神经元丢失).

But scientists might have just the thing to change the situation. And it involves a nose. In a study published in the journal ACS Omega, researchers from China's Zhejiang University created an "e-nose," a portable device that can detect body smells specific to Parkinson's patients.

It may come as a surprise to learn Parkinson's patients have their own smells. But after a retired nurse in Scotland made headlines in 2015 for a heightened sense of smell that led to her own husband's Parkinson's diagnosis, scientists have been trying hard to create a device that could smell the disease before physical symptoms start to show.

Over the years, scientists have found people with Parkinson's tend to produce more sebum(皮脂) than the average person. This sebum mixes with other overproduced substances to produce certain, unique smells.

To track down these smells, the Zhejiang University researchers swabbed(用拭子擦拭) the upper back of 31 Parkinson's patients and 32 healthy volunteers. Using machine-learning software, they were able to identify three smell compounds(化合物) that healthy volunteers lacked. The researchers then tested the e-nose on sebum taken from 12 Parkinson's patients and 12 healthy people. The device was found to be about 71 percent accurate in distinguishing healthy sebum from Parkinson's sebum.

These are encouraging findings, but before the e-nose is ready for clinical use, the team needs to test it on many more people to improve the accuracy of the models. They will also need to test whether factors like race affect the e-nose's performance in any way. But for now, as the number of people living with Parkinson's in the U.S. is expected to rise to 1.2 million by 2030, a nose might be the best option to detect this disease.