Alzheimer's early signs: Declining sense of smell could be first warning of decline, not memory loss

A new study provides the most conclusive evidence yet

Sarah Jones
Tuesday 15 November 2016 12:41 GMT
Comments
This isn't the first time researchers have explored smell as a symptom of the disease
This isn't the first time researchers have explored smell as a symptom of the disease (Doug Sparks)

Your support helps us to tell the story

This election is still a dead heat, according to most polls. In a fight with such wafer-thin margins, we need reporters on the ground talking to the people Trump and Harris are courting. Your support allows us to keep sending journalists to the story.

The Independent is trusted by 27 million Americans from across the entire political spectrum every month. Unlike many other quality news outlets, we choose not to lock you out of our reporting and analysis with paywalls. But quality journalism must still be paid for.

Help us keep bring these critical stories to light. Your support makes all the difference.

A declining sense of smell could be the first sign of Alzheimer’s, not memory loss, according to new research.

Researchers at Masachusetts General Hospital in the US have developed a method which can identify a person’s risk for the disease on the basis of their ability to recognise and recall odours.

While this isn’t the first time smell has been explored as a symptom, it does provide the most conclusive evidence yet.

Lead investigator Dr Mark Albers even goes as far to say that a hindered sense of smell caused by Alzheimer’s could be detected a decade before patients start to experience memory loss.

This new method means that Alzheimer's could be detected 10 years before memory loss symptoms
This new method means that Alzheimer's could be detected 10 years before memory loss symptoms (Rex)

"There is increasing evidence that the neurodegeneration behind Alzheimer's disease starts at least 10 years before the onset of memory symptoms," he says.

The study of 183 patients deemed to have an increased risk of developing the disease found that those with early signs of Alzheimer’s were less likely to be able to identify or easily recognise smells.

First, they were tested for how well they could identify smells by being presented with 10 scents: menthol, clove, leather, strawberry, lilac, pineapple, smoke, soap, grape or lemon.

After smelling each one they were asked which, if any, were familiar and to pick the name of the scent from a choice of four.

Next, they were given a questionnaire asking about the scents they just smelled. This was used to test their awareness and memory of smells.

Finally, to test how well they could discriminate between smells they were given a choice of two and asked if they were the same or different.

As a result, the study was able to identify the participants whose brain scans showed hallmark signs of Alzheimer’s purely based on their sense of smell.

The tests were designed to measure patients' ability to recognize, remember and distinguish between smells
The tests were designed to measure patients' ability to recognize, remember and distinguish between smells

"It is well recognized that early diagnosis and intervention are likely to produce the most effective therapeutic strategy for Alzheimer's disease - preventing the onset or the progression of symptoms," says Albers.

"If these results hold up, this sort of inexpensive, noninvasive screening could help us identify the best candidates for novel therapies to prevent the development of symptoms of this tragic disease."

Join our commenting forum

Join thought-provoking conversations, follow other Independent readers and see their replies

Comments

Thank you for registering

Please refresh the page or navigate to another page on the site to be automatically logged inPlease refresh your browser to be logged in