Researcher finds elderly lose ability to distinguish between odors

November 10, 2011

Scientists studying how the sense of smell changes as people age, found that olfactory sensory neurons in those 60 and over showed an unexpected response to odor that made it more difficult to distinguish specific smells, putting them at greater risk from dangerous chemicals and poor nutrition.

"We found clear changes in olfactory sensory neuron responses to odors for those 60 and up," said Professor Diego Restrepo, Ph.D., director of the Center for NeuroScience at the University of Colorado School of Medicine who led the researchers. "When we presented two different odors to the olfactory sensory neurons of younger people they responded to one or the other. The sensory neurons from the elderly responded to both. This would make it harder for the elderly to differentiate between them."

According to the study published in the latest issue of of Aging, those losing their sense of smell are at a higher risk of since taste and smell are closely related, they may also be unable to detect spoiled food, leaking gas or toxic vapors.

Researchers looked at 440 subjects in two age groups – those 45- years-old and younger and those 60 and over. Their olfactory (OSNs) were tested for their responses to two distinct odors as well as subsets of those odors.

Restrepo wanted to determine if age-related differences in the function of OSNs might contribute to an impairment of the . For this, in a collaboration with Monell Chemical Senses Center in Philadelphia, researchers biopsied cells from both age groups.

"Whereas cells from younger donors were highly selective in the odorants to which they responded, cells from older donors were more likely to respond to multiple odor stimuli… suggesting a loss of specificity," the study said.

The scientists had expected to find less OSNs in older subjects and they thought the neurons would be less likely to respond to stimuli. In fact, they found as many neurons in the old as the young but those over 60 could not differentiate between two odors, they blended together.

The study suggests that changes in nose and the brain contribute to smell loss in the elderly, Restrepo said.

Related Stories

Recommended for you

Motivation to bully is regulated by brain reward circuits

June 29, 2016

Individual differences in the motivation to engage in or to avoid aggressive social interaction (bullying) are mediated by the basal forebrain, lateral habenula circuit in the brain, according to a study conducted at the ...

New clues about the aging brain's memory functions

June 29, 2016

A European study led by Umeå University Professor Lars Nyberg, has shown that the dopamine D2 receptor is linked to the long-term episodic memory, which function often reduces with age and due to dementia. This new insight ...

New technology could deliver drugs to brain injuries

June 28, 2016

A new study led by scientists at the Sanford Burnham Prebys Medical Discovery Institute (SBP) describes a technology that could lead to new therapeutics for traumatic brain injuries. The discovery, published today in Nature ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.