Losing sense of smell an early warning sign for people carrying Alzheimer’s gene

CHICAGO — A new study finds that people with a specific gene could experience a particular early warning sign that they’re developing dementia — losing their sense of smell. This isn’t the first study to link the sense of smell to cognitive decline, but researchers in Chicago are now connecting a well-known Alzheimer’s gene variant to the problem.

Researchers discovered that individuals with the APOE e4 gene were 37 percent less likely to have a good sense of smell. Those who carried this gene, known to increase the risk of Alzheimer’s, experienced a decline in their ability to detect scents between the ages of 65 and 69.

Using a scale from zero to six to measure the number of odors participants could detect, gene carriers in that age group could identify an average of 3.2 smells, compared to 3.9 smells for those without the gene. By the time gene carriers reached 75 to 79, they began to struggle to identify scents, and their ability to smell declined more rapidly than non-carriers. However, the researchers noted that thinking and memory skills were similar between the two groups, although gene carriers experienced a faster decline in their cognitive abilities over time.

“Testing a person’s ability to detect odors may be a useful way to predict future problems with cognition,” says Dr. Matthew GoodSmith of the University of Chicago in a media release. “While more research is needed to confirm these findings and determine what level of smell loss would predict future risk, these results could be promising, especially in studies aiming to identify people at risk for dementia early in the disease.”

Scroll down to see 8 healthy habits that help prevent Alzheimer’s

older woman smelling white flower
Photo by Taylor Deas-Melesh from Unsplash

The researchers conducted their study by testing participants’ ability to detect and identify odors while also analyzing DNA samples to identify those carrying the Alzheimer’s-linked gene. Over five years, the participants completed surveys at home to measure their olfactory abilities, and their thinking and memory skills were also assessed twice, five years apart.

This research highlights the potential of using smell detection as an early indicator of cognitive decline and dementia risk. Further investigation into the relationship between smell and neurodegeneration could offer valuable insights into identifying and understanding the onset of dementia.

The study is published in the journal Neurology.

8 healthy habits that lower Alzheimer’s risk

While scientists work on new drugs to help those displaying symptoms or at high risk for Alzheimer’s disease, there are several drug-free steps you can take to lower your chances of developing Alzheimer’s in the first place.

  1. Being active
  2. Eating better
  3. Losing weight
  4. Not smoking
  5. Maintaining healthy blood pressure
  6. Controlling cholesterol
  7. Reducing blood sugar
  8. Getting good quality sleep

“The good news is even for people who are at the highest genetic risk, living by this same healthier lifestyle are likely to have a lower risk of dementia,” Professor Adrienne Tin from the University of Mississippi says in a statement.

South West News Service writer Pol Allingham contributed to this report.

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  1. Having a family history of Alz, I follow all the articles. I’m terrified every time that I forget something that “this is it, beginning of the end.” Now I’ll add sniffing things to my list of “am I ok?” things.

    I will say that sadly, the list of “do this to help” has not been proven to me to be helpful. My mother outshone my dad in every aspect of that list, and she got early onset Alz and died, and he died years later of not controlling his diabetes. Go figure.

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