Can you recognize some of the earliest signs of dementia? Perhaps you know a few common symptoms, such as memory loss or confusion while driving. But thanks to a team at McGill, University in Canada, there could be a new symptom that appears years before the disease affects a patient’s day-to-day life.

According to their recent study published in the journal Neurology, the inability to distinguish between bubblegum and gasoline scents could be a new way to detect Alzheimer’s disease and dementia.

While we know how to prevent the treatable causes of dementia, identifying its symptoms has been much tougher. For over 30 years, scientists have believed there is a link between memory loss and difficulty with smell. This new research suggests that one of the first signs of dementia development could be damage to the olfactory neurons, which are involved in distinguishing certain scents.

To test the theory, the Canadian team recruited 300 people whose parents have dementia and asked them to take scratch-sniff tests to identify strong aromas such as gasoline, bubblegum, and lemon. One-third of these participants also agreed to participate in a test that would detect if they were at risk for the disease.

The final data showed that those with the most difficulty in identifying odors also displayed other indicators of Alzheimer’s disease.

“This is the first time that anyone has been able to show clearly that the loss of the ability to identify smells is correlated with biological markers indicating the advance of the disease,” lead author Marie-Elyse Lafaille-Magnan said.

As it turns out, both the olfactory bulb, which determines smells, and the entorhinal cortex, which is tied to memory and naming of odors, are among the first brain structures first to be affected by Alzheimer’s, according to Lafaille-Magnan.

Does the inability to smell peanut butter mean you have Alzheimer’s?

[Source: Huffington Post]