The findings, published online Nov. 15 in JAMA Neurology, are based on 1,019 adults aged 50 to 64 who were surveyed in 2018. They were asked whether they thought they were “somewhat likely,” “very likely” or “unlikely” to develop dementia in their lifetime.
Overall, 44% believed they were somewhat likely, while 4% chose the “very likely” option.
How accurate were they? It’s hard to say, since the terms are vague, according to Keith Fargo, director of scientific programs and outreach for the Alzheimer’s Association.
But, he added, it would be reasonable for anyone to see themselves as somewhat likely to develop dementia: Around 10% of Americans aged 65 and older have dementia; the rate soars to roughly one-third among people aged 85 and up.
Fargo, who was not involved in the study, said that more can be gleaned by looking at the responses of different groups of participants.
For example, black Americans were much more likely than whites to see themselves as unlikely to develop dementia: 63% endorsed that belief, versus 49% of white respondents.
It’s thought that people with more education, or who engage in lifelong learning, may have more “cognitive reserve,” Fargo explained. The theory is, those people can withstand more of the brain damage that marks dementia before developing symptoms.
Studies are ongoing to figure out the best strategies for slowing or preventing dementia. Fargo said the Alzheimer’s Association is sponsoring a trial, called U.S. Pointer, that is testing a combination of tactics — including diet, exercise, and mental and social stimulation.
For now, Maust said the best bet is to take care of your overall health and control any chronic medical conditions — especially those that affect the heart and blood vessels, like high blood pressure and diabetes. Studies have long noted a connection between heart health and dementia, and a recent clinical trial showed that tight control of high blood pressure curbed older adults’ risk of mild cognitive impairment.
“I think people may not appreciate the extent to which risk of dementia can be reduced by addressing chronic medical conditions,” Maust said.
If you believe your memory or thinking skills are deteriorating, Fargo advised seeing your doctor.
“In some cases,” he said, “there may be a treatable underlying cause, like sleep apnea, vitamin-B12 deficiency or depression.”