It’s not a secret that millions of Americans suffer from cognitive disorders like dementia, Alzheimer’s disease and mild cognitive impairment. However, a recent study published in the journal JAMA Neurology illustrates just how prevalent these conditions are.
In the first nationally representative study of cognitive impairment in more than 20 years, researchers from Columbia University found almost 10% of adults in the U.S. 65 and older have dementia, while an additional 22% have mild cognitive impairment. Additional new research from a RAND Corporation study showed that overall, the rate of dementia in the U.S. fell by nearly a third from 2000 to 2016.
While the Columbia University study found that men and women have similar rates, the researchers report that people with dementia and MCI are more likely to have lower levels of education and identify as black or Hispanic.
“This is important because we need to understand better why dementia risk is distributed unequally from the perspectives of ethics, public health and public policy,” said Jennifer Manly, PhD, the study’s lead author and professor of neuropsychology at the Gertrude H. Sergievsky Center and the Taub Institute for Research on Alzheimer’s Disease and the Aging Brain at Columbia University.
The study was based on data from 3,500 people over age 65 who were enrolled in the Health and Retirement Study. A randomly selected sample of participants was asked to complete neurological examinations that tested for memory and comprehension along with in-depth interviews.
Manly and her colleagues discovered different rates of dementia and mild cognitive impairment from the participants based on three categories, including age, race and education level:
- Those who were 90 and older had the highest rates of dementia and MCI.
- Only 3% of adults between 65 and 69 had dementia, while 35% of adults 90 and older had dementia.
- Every five-year increase in age was linked with a higher risk.
- 22% of older adults who self-identified as black or African American developed MCI and 15% developed dementia.
- 28% of people who identified as Hispanic/Latino developed MCI and 10% of adults had dementia.
- 21% of white older adults developed MCI while 9% developed dementia.
- 9% of people with a college degree or higher developed dementia compared to 13% of adults with less than a high school degree.
- 21% of adults over 65 with a college degree or more developed MCI while it was 30% of adults with less than a high school diploma.
- Each additional year of education was associated with a decrease in the risk of dementia and MCI.
Why is this study important and what needs to happen?
Kristina Lubofsky, MSG, a gerontologist and founder of Busy Minds Box, told Seasons this study not only builds on previous knowledge about the prevalence of dementia but also mild cognitive impairment—which, in many cases, leads to dementia. This study also includes valuable demographic differentiation in terms of race, she said, which has been lacking in previous data.
“There are so many people who are diagnosed every day, and so many more who go undiagnosed,” she said. “Every study that builds on research around the prevalence of dementia in the U.S. adds to our understanding of the bigger picture.”
Manly added this data is critical for understanding the causes, costs and consequences of dementia and MCI and for advising policies meant to reduce their impact.
“Actions and policies that decrease discriminatory and aggressive policing policies, invest in schools that serve children that are racialized as black and Hispanic, repair housing and economic inequalities, and provide equitable access to mental and physical health can help to narrow disparities in later life cognitive impairment,” Manly said.
Two other areas that policymakers can focus on, she added, include the shortage in the workforce of dementia care specialists and paid family leave for caregiving.
“The U.S. has a ‘National Plan to Address Alzheimer’s Disease,’ and it will be especially important to integrate solutions for the causes of disparities in dementia risk within that plan,” Manly said. “This is especially the case now because the pandemic has made health and well-being even more unequal in the U.S., and disadvantaged groups are at especially high risk.”
Why might race and education level impact dementia risk?
Black and Hispanic adults are more likely to develop cognitive impairment and dementia because of historical and current structural racism and income inequality, Manly said, that restricts access to brain health benefits and increases exposure to harm. Furthermore, she claims those who have low levels of education are also at higher risk because of structural disparities.
“The reasons … are not caused by the individual—the causes are structural,” she said. “In other words, disparities are caused by unfair and unjust inequalities from birth, through adulthood and into older age, in access to health care, wealth, power and safety. So, changes in these structural issues are the solution.”
What does this information mean for you?
If you or a loved one have concerns about dementia, it’s important to be familiar with the warning signs and symptoms of dementia, including memory loss, challenges in planning or problem-solving, and difficulty completing daily tasks.
Manly said if there are any warning signs present, caregivers, older adults and families can speak with their doctor about any changes in function, memory and thinking abilities along with concerns and the next steps to take.
However, she noted: “Not all doctors are attuned to the signs of dementia, so patients and family might have to reach out to other members of the medical care team, including nurses, physician assistants, social workers, and groups that advocate for patients – like the Alzheimer’s Association – to make sure their voice is heard.”
“It is never too late to start reducing your risk of dementia,” she said. “We may not notice the benefits immediately, but when we look back, the changes we have made to invest in our future selves do matter.”