About half of middle-aged Americans believe they’re “somewhat” or “very likely” to develop dementia, a survey suggests, and many try to beat the odds with supplements such as ginkgo biloba and vitamin E that aren’t proven to help.

Researchers examined data from the University of Michigan’s 2018 National Poll on Healthy Aging, a nationally representative survey of adults 50 to 80. Overall, 44.3 percent of respondents said they were at least somewhat likely to develop dementia, and 4.2 percent said they were very likely to develop dementia.

Just 5.2 percent of survey participants said they had discussed dementia prevention with their doctor, the study also found.

Nonetheless, 31.6 percent said they took fish oil or omega-3 fatty acids hoping that it would help lower their risk, and 39.2 percent took other vitamins or supplements. More than half of participants also believed doing crossword puzzles could help stave off dementia.

“Given repeated failures of disease-preventing or disease-modifying treatments for dementia, interest in treatment and prevention have shifted earlier in the disease process,” study leader Donovan Maust of the University of Michigan in Ann Arbor and colleagues write in JAMA Neurology.

The authors point out that overestimating one’s own risk combined with an embrace of ineffective preventive measures could lead to a lot of wasted spending, even if effective preventive treatments are discovered one day.

“Adults in middle age may not accurately estimate their risk of developing dementia, which could lead to both overuse and underuse if preclinical dementia treatments become available,” Maust and colleagues write.

About 1.6 percent of the U.S. population had Alzheimer’s disease and other forms of dementia as of 2014, according to the Centers for Disease Control and Prevention. By 2060, this will more than double to 3.3 percent of the population.

Advancing age is the biggest risk factor for dementia, along with family history, being African American or Hispanic, or having poor cardiovascular health or a traumatic brain injury, the CDC says.

Normal age-related memory changes can include things such as occasionally losing car keys or forgetting the name of an acquaintance, but this might not necessarily lead to dementia. With dementia, people might use unusual words to refer to familiar objects or forget the name of a close friend or loved one.

— Reuters