Scratch-and-Sniff Test Predicts Parkinson’s Earlier

New research from a Michigan State University study showed further evidence that a simple scratch-and-sniff test could potentially identify people at an increased risk of developing the disease up to 10 years before traditional diagnosis. Previous research showed an association between the progression of disease and sense of smell up to four to five year early.

The study had participants smell 12 common odors such as cinnamon, soap, and lemon then select the correct answer from four choices. Participants had an average age of 75 and consisted of 1,510 whites and 952 blacks. Those with a poor sense of smell were  nearly five times more likely to develop the disease.

Participants were divided into three groups — poor sense of smell, medium and good. Out of the 764 that were categorized as having a poor sense of smell, 26 developed the disease. Compared to 9 of 863 with medium and 7 of 835 with good senses of smell and the correlation stands out.

Michigan State University researcher Honglei Chen explained, “It’s important to note that not everyone with low scores on the smell test will develop Parkinson’s disease. 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 characterize populations that are at higher risk for the disease and to identify other factors involved.”