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Research ties ability to recognize scents to risk of Alzheimer’s

Researchers say the first clue that a person is at risk of Alzheimer’s disease may be at the tip of his nose.

A study out of Massachusetts General Hospital has found that a decline in a person’s ability to recognize an odor may be an early indication of the degeneration of the brain associated with Alzheimer’s.

“There is increasing evidence that the neurodegeneration behind Alzheimer’s disease starts at least 10 years before the onset of memory symptoms,” said Mark Albers, M.D., Ph.D., principal investigator of the report.

He said the findings may point the way to therapies that can impede the advance of the disease, which robs people of their memories and ability to think logically.

Said Albers, “The development of a digitally enabled, affordable, accessible and non-invasive means to identify healthy individuals who are at risk is a critical step to developing therapies that slow down or halt Alzheimer’s disease progression.”

Testing the sense of smell

The Massachusetts General researchers developed a series of tests to assess both a person’s cognitive abilities and ability to recognize, remember and distinguish smells. They included:

  • An odor perception identification test that offered participants 10 odors – menthol, clove, leather, strawberry, lilac, pineapple, smoke, soap, grape or lemon – then asked them whether they recognized the scent and asked them to identify it by choosing from the 10 choices
  • An odor awareness questionnaire to assess participants’ attention to environmental odors and how they are affected by them
  • A second perception identification test over the 10 flavors above, plus banana, garlic, cherry, baby powder, grass, fruit punch, peach, chocolate, dirt and orange in which participants were asked if they remembered the scents from the previous test and to describe what they smelled
  • An odor discrimination test that asked participants to distinguish between two consecutive scents

The study examined results from 183 participants enrolled at the Massachusetts General Alzheimer’s Disease Research Center. It found that a person’s ability to remember and distinguish among scents differed considerably between people who tested normal for cognition and those with Alzheimer’s.

Albers and his team are recruiting participants for a broader study to validate these results.

Talk to your health care provider about any concerns you have about your memory or ability to think. Providence has extensive resources that can help you deal with symptoms, such as deterioration in memory, a sense of disorientation or mood changes, that may be associated with neurodegeneration. You can find a Providence provider here.

To learn more

We’ve written extensively about Alzheimer’s, from tips on keeping your brain active to the promising developments in research:

The Centers for Disease Control and Prevention offers a resource page that describes Alzheimer’s symptoms and treatments. (The resource page recognizes the role that family and friends play as caregivers for people living with Alzheimer’s, but it doesn’t actually give any tips on supporting those people.)

The study, “Episodic Memory of Odors Stratifies Alzheimer Biomarkers in Normal Elderly,” was published online in the Annals of Neurology. A reader-friendly description of the study was published by Massachusetts General Hospital.