As we grow older, our senses diminish. We might not see or hear as well as we once did, but we accept that as the normal part of aging. We may start wearing bifocals and buy hearing aids.
Our sense of smell also fades over time, and new research has found this can have has serious health implications. For example, a lessened ability to detect odors can predate the onset of tremors and other symptoms of Parkinson’s disease by up to eight years. It also could be a warning sign of dementia and even death.
Researchers in Sweden and at Michigan State University studied data from more than 2,000 older adults who took a 12-odor smell test. They found those who scored 8 or below had a 46% higher risk of dying within 10 years and a 30% higher risk of death by year 13 than those whose ability to smell remained strong.
Our sense of smell helps us detect and avoid eating spoiled food, keeps us out of environmentally dangerous settings and helps us maintain healthy personal hygiene. It can also sustain a strong appetite, which leads to better nutrition and helps us maintain our balance so we don’t fall and injure ourselves.
So, why are we just learning about this now? The answer, in part, is that similar studies had follow-up periods of four to five years, so the long-term results were not as well-known. By contrast, participants in this study were reassessed at four time points across a 13-year period.
Most older adults aren’t even aware that their sense of smell is failing, and it is rarely tested in clinical settings. Given what’s at stake, it may be time for health care providers to add smell tests to the vision and hearing exams they administer each year.