This sneaky sign of dementia can show up a decade before other symptoms
Losing your sense of smell is nothing to sneeze at — it could be an early sign of dementia.
“Odor identification has been identified as a useful screening tool that predicts conversion from mild cognitive impairment to Alzheimer’s disease dementia,” Virginia neurologist Fouzia Siddiqui told Parade last week.
Nearly 7 million Americans have been diagnosed with dementia, which gradually destroys memory, thinking skills and the capacity to perform basic tasks. Researchers have long known the strong link between anosmia — the medical term for the loss of smell — and an increased risk of dementia.
While identifying Alzheimer’s risk factors like genetic variants typically requires comprehensive testing, anosmia can be noticeable during daily activities. Experts suggest consulting a doctor if you can’t smell your shampoo, conditioner or shower gel while bathing.
“The process of neurodegeneration that causes dementia can also affect sensation and sensory processing related to smell, making it harder for [patients] to recognize familiar scents like their favorite shampoo or body wash,” Dr. Meredith Bock, a board-certified neurologist and chief medical officer at Remo Health, explained to Parade.
Siddiqui said in the case of Lewy body dementia — the second most common form of dementia after Alzheimer’s — the reduced or distorted ability to smell can precede other symptoms by almost a decade.
The clumps of built-up protein that signal Alzheimer’s tend to first appear in brain regions associated with memory and olfaction before spreading to other parts of the brain.
A 2022 study from University of Chicago Medicine found that people with a rapid decline in their sense of smell had a smaller volume and shape of grey matter in the olfactory- and memory-associated areas than people who had less issue with their sniffer.
In fact, one study determined that older adults who can’t identify scents are three times more likely to die within five years than healthy senior citizens.
“Unfortunately, if the loss of smell and taste is due to a neurodegenerative disorder, such as Alzheimer’s disease or Parkinson’s disease, it does not come back,” Bock said.
Anosmia doesn’t always mean you have dementia. It can be a symptom of a cold, the flu, COVID-19, head trauma, vitamin deficiency and even normal aging.
“As we age, it’s normal for our senses to change,” Bock told Parade. “For people living with dementia, these changes can be more noticeable.”
It’s important to tell your healthcare provider about any noticeable changes. Recent research from the University of Michigan found that millions of Americans likely have dementia symptoms but no formal diagnosis in part because patients misunderstand their symptoms as normal aging.
Risk factors of dementia include lower levels of education, hearing loss, high blood pressure, tobacco use, obesity, depression, diabetes, excess alcohol intake, traumatic brain injury, air pollution, social isolation, vision loss, high cholesterol and a sedentary lifestyle.
