How would you rate your risk of developing dementia? This question was part of a series of questions posed to 1,000 elderly Americans, aged 50 to 64, in a nationally representative health survey published online last week in the peer-reviewed scientific journal, JAMA Neurology.

The survey results were surprising. Almost half of respondents believed they were likely to develop dementia. It also showed many elderly Americans inaccurately estimating their chances for developing dementia and to do useless things to prevent it such as taking supplements of doubtful value.

A large number of respondents who rated their health as fair or poor thought their dementia chances were low. Others who said they were in excellent health believed they were likely to develop dementia.

Among those that said their physical health was only fair or poor, 40 percent thought they were at low risk for Alzheimer’s disease or other dementias. Almost the same portion rated their chances as likely even though they reported very good or excellent physical health.

The results of the study suggest many elderly Americans don't understand the connection between physical health and brain health. It also shows how racial differences can affect dementia risk.

Many respondents said they tried at least one of four unproven methods that allegedly protect memory, including taking supplements like fish oil and ginkgo. The most popular strategy to exercise aging minds was doing crossword puzzles.

One in three seniors die with Alzheimer’s or other dementias, according to the Alzheimer’s Association.

“We really haven’t done a good job of getting the word out that there really are things you can do to lower your risk,” Dr. Donovan Maust, the study’s lead author and a geriatric psychiatrist at the University of Michigan, said.

Doctors say mental stimulation is thought to help fend-off dementia. There is stronger evidence, however, more challenging activities than puzzles (playing chess, taking a class, reading about unfamiliar topics) might be more effective, according to Keith Fargo, who oversees research and outreach programs at the Alzheimer’s Association.

The survey also showed more whites than African Americans or Hispanics surveyed believed they were likely to develop dementia. On the other hand, almost two-thirds of blacks said they were unlikely to develop dementia. Only 93 blacks were included in the survey, however. This made it difficult to generalize those results to all African Americans. U.S. minorities face higher risks for dementia than whites — African Americans face double the risk, for example.

“There’s lots of work to do ... to educate the public so they can take some actions to protect themselves,” Fargo said.

There are no medicines or medical treatments proven to prevent Alzheimer's. Rigorous European studies have shown healthy lifestyles might help prevent dementia and mental decline.

The study used data from the University of Michigan National Poll on Healthy Aging. Adults were surveyed online in October 2018. Funding came from AARP, the University of Michigan health system and U.S. government grants.

Dementia affects millions of people worldwide, according to the World Health Organization. Photo courtesy of Pixabay