Being able to tell smells apart may mean that you are likely to live longer. A new study conducted by researchers at Michigan State University has found that elderly people with a poor sense of smell have a higher likelihood of dying within a 13-year window. The study has been published in the journal Annals of Internal Medicine.
In the new study, Michigan State University epidemiologist Honglei Chen and the rest of his team used data from a long-running study of elderly individuals called the Health ABC study to study the link between olfactory sensitivity and likelihood of death. The researchers used the data of nearly 2,300 older adults, ages 70 to 79, living in Pittsburgh or Memphis, who completed a smell test at the beginning of the study, between 1997 and 1998.
During the smell test, the participants were asked to identify 12 common smells, such as cinnamon, lemon, gasoline, and smoke. The participants were grouped into “good”, “moderate” or “poor” sets, depending on how many correct answers they gave. Those who correctly identified no more than eight smells were placed in the “poor” group.
The participants remained in the study until their deaths or until 2014, a total follow-up period of 13 years. During that period roughly 1,200 study participants died.
According to the results, elderly people with a poor sense of smell had a 46 percent higher risk of death within the first ten years after testing and a 30 percent higher risk of dying by year 13, compared to those who were in the “good” group. The association held across race and gender, but the link was only present among those who rated their health as good at the start of the study.
According to the paper, about a quarter of older Americans experience a decline in sense of smell. Unfortunately, people are often unaware of their sense of smell degrading and it’s rarely tested by doctors. These types of smell tests could help doctors identify older adults who are at greater risk of developing dementia. It is thought the sense of smell is one of the first bodily functions affected by certain neurodegenerative diseases.