A failing sense of smell could mark the start of memory problems and even Alzheimer’s disease according to a new study. According to the report, researchers found that older adults who had the worst sense of smell tested more than twice as likely to have mild memory problems.
If they already had memory problems, they were more likely to progress to full-blown Alzheimer’s disease, according to lead researcher Rosebud Roberts, a professor of neurology at the Mayo Clinic in Rochester, Minnesota.
This report, published in the journal JAMA Neurology, confirms suspicions some doctors have had for years. In fact, doctors who treat Medicare patients informally use what is called the “Peanut Butter Test” to gauge a person’s Alzheimer’s risk. If the patient can’t smell the strong aroma of peanut butter, they are more likely to have early dementia, according to those who subscribe to the test.
Roberts said that the findings of the study do not apply to people who have always had problems smelling because of chronic respiratory conditions.
According to Roberts:
The findings suggest that doing a smell test may help identify elderly, mentally normal people who are likely to progress to develop memory problems or, if they have these problems, to progress to Alzheimer’s dementia. Physicians need to recognize that this may be a possible screening tool that can be used in the clinic.
It’s possible that as dementia begins and progresses, the parts of the brain that distinguish smells from one another starts to worsen as well, according to Roberts.
In the study, as the inability to differentiate odors increased, so did the chance of having memory problems and Alzheimer’s disease. However, this link was not proven to have a cause-and-effect relationship. A link between a decreased sense of smell and other thinking problems associated with mild cognitive impairment was not found.
The study collected data on more than 1,400 mentally normal adults with an average age of 79.