Parkinson’s disease symptoms: Being unable to smell THESE scents could reveal condition

Researchers believe they have discovered a way to predict risk of Parkinson’s disease up to ten year’s before people are actually diagnosed.

A study by Michigan State University has revealed that sense of smell was linked to progression of the condition.

They found that people with a poor sense of smell were almost five times more likely to develop the disease than people with a good sense of smell.

In the study, 2,462 participants with an average age of 75 were asked to smell 12 common odours including cinnamon, lemon, petrol, soap, and onion. 

Scientists also noted that sense of smell and Parkinson’s risk varied between ethnicities and gender.

“We found that there was a strong link between smell and disease risk for up to six years,” said Honglei Chen, professor of epidemiology at Michigan State University.

“One of the key differences in our study was we followed older white and black participants for an average of about 10 years, much longer than any other previous study.”

They discovered that the relationship between smell and Parkinson’s risk in black participants was not as strong as in white participants.

Researchers also found that older men with a poor sense of smell are more likely to develop the disease than women.

In the study the researchers looked at 1,510 white and 952 black participants.

They were then monitored for a decade.

By the end of the study there were 42 people who had developed Parkinson’s. 

Of that group 26 had a poor sense of smell, seven had a good sense of smell and nine had a sense of smell that was categorised as medium.

“It’s important to note that not everyone with low scores on the smell test will develop Parkinson’s disease,” said Chen.

“More research is needed before the smell test can be used as a screening tool for Parkinson’s, but we are definitely on to something and our goal now is to better characterise populations that are at higher risk for the disease and to identify other factors involved.”

In the UK, there are currently 127,000 people with Parkinson’s disease.