Do you think any person can smell a disease? Is the human nose a powerful organ to do so?

Well, there is a woman in Scotland who can smell Parkinson's disease. Joy Milne sensed a different odor from her husband, Les Milne when he returned home after work. She insisted he take a bath, but still, the smell persisted. But it was only she, who could sense this odor from him.

She described the smell as musky yeast. Les, a doctor, was 33, and Joy, a registered nurse, was 31 at that time. Twelve years later, Les was diagnosed with Parkinson's disease, a progressive disorder of the central nervous system that causes uncontrollable movements.

For the next 20 years, they tried to fight his Parkinson's and then decided to attend a support group. They were a bit late for the meeting, and the hall was full of Parkinson's patients.

To Joy's surprise, all patients had a strong odor similar to Les's. As soon as they reached home, Joy told this to Les, and they decided to approach Dr. Tilo Kunath, a Parkinson's researcher at the University of Edinburgh, to find a connection between the odor and Parkinson's disease.

Dr. Kunath initially dismissed this as he thought it was impossible for a disease like Parkinson's to have a smell. But a few months later, he learned about research that implied that dogs could sense tumors. Immediately, he contacted Joy and asked her to be a part of his experiment.

For the experiment, Dr. Kunath asked a group of people with Parkinson's and another group of people without Parkinson's to take white t-shirts home and wear them overnight. The next day, they collected t-shirts from all participants and numbered them randomly. Joy was asked to smell and identify Parkinson's patients.

She was able to identify Parkinson's patients as well as the stage of the disease based on the intensity of the smell. But she made one mistake. She wrongly identified a man without Parkinson's as having Parkinson's. However, after a few months, that man came to see Dr. Kunath and was told he had been diagnosed with Parkinson's. Hence, they reached the conclusion that Joy can detect Parkinson's even before the onset of symptoms.

So far, there is no cure for Parkinson's, and is also hard to diagnose. Doctors diagnose Parkinson's on the basis of symptoms, which include;

• tremors

• masked face

• difficulty in walking and sleeping

• anosmia, or loss of smell

• dizziness

• drooling

Parkinson's disease is caused by the loss of nerve cells in the Substantia Nigra (SN) part of the brain that is responsible for the production of dopamine, a chemical that is essential for controlling and coordinating body movements. Hence, the reduction in the level of dopamine causes difficulty with movements and activities requiring coordination. Symptoms of Parkinson's disease typically don't appear until the substantia nigra has lost about 50% of its nerve cell activity.

Even though there is no cure, symptoms can be managed with the help of certain medications. Surgical procedures and advanced treatment methods have been developed in recent years to manage Parkinson's disease effectively.

But the reason for the odor in Parkinson's patients is still making scientists ponder. Research suggests that the condition can be detected by analyzing sebum using mass spectrometry, a technique that weighs molecules. There are certain chemicals that are found only in Parkinson's patients.

Joy published an article in ACS Central Science along with Dr. Kunath and his colleagues about their work. She also worked at the University of Manchester for three years.

Joy often finds it difficult to go to public places as she gets a strong scent of perfume and the odor of sweat from other people. "Joy Milne was found to have an inherited disorder known as hereditary hyperosmia, wherein she could smell substances that adults with normal olfaction could not smell", says Dr. Abhishek Aravind. Researchers think Joy may have a nose for more diseases than Parkinson's. She has also noted distinct odors in persons with Alzheimer's, cancer and tuberculosis, and she is collaborating with scientists to determine if specific olfactory biomarkers of those diseases can be found.

Les passed away in June 2015 at the age of 65. He spent his last days with Joy writing about their whole journey. He didn't want Joy to give up their research, and she is still working with many scientists and researchers to help ease the lives of people with Parkinson's disease.

Sources:

1. https://www.npr.org/sections/health-shots/2020/03/23/820274501/her-incredible-sense-of-smell-is-helping-scientists-find-new-ways-to-diagnose-di

2. https://www.theguardian.com/society/2022/sep/07/woman-who-can-smell-parkinsons-helps-scientists-develop-test

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