Cognitive decline impacts many people as they age, which can have a profound impact on their lives. There’s good news on this front in the United States, though. A new survey has found that there’s been a stark drop in the number of Americans experiencing serious cognitive impairment over the past decade.
Researchers from the University of Toronto examined survey data from more than 5 million American seniors between 2008 and 2017, finding that the number of participants who reported serious cognitive problems declined by nearly 20% in that time. The study, published in the Journal of Alzheimer’s Disease, provides hope that fewer Americans will be impacted by poor cognitive health in the future.
Esme Fuller-Thomson, lead author and director of the University of Toronto’s Institute for Life Course & Aging, says, “We were astonished to see the prevalence of cognitive impairment decrease so sharply over such a short period of time. This decline in the prevalence of serious cognitive problems has a cascade of benefits for older adults, their families and caregivers, the health and long-term care system, and the whole US economy.”
To investigate the prevalence of these cognitive issues, the research team used 10 years of responses to the American Community Survey, an annual survey of half a million Americans aged 65 and older. Overall, 5.4 million responses were included in this study’s data.
Each year, the participants are asked if they had serious difficulty concentrating, remembering, or making decisions. In 2008, 12.2% had responded yes to this question. However, by 2017, it was only 10%. The authors say this means 1.13 million fewer Americans were experiencing these problems in 2017 than there would have been if the 2008 prevalence had persisted.
The drop off was sharpest among women, who saw a 23% decrease, while men had a slightly more modest decrease of 13%. When broken down into smaller age brackets by gender, all groups experienced a significant decline, except for men between the ages of 65 and 69.
Researchers say generational differences in educational attainment played a role in the sharpness of reduction, with 60% of the overall decline attributable to this. Studies have found that each additional year of formal schooling is linked with a lower risk of dementia. Compared with our oldest Americans, each successive generation has had more access to post-secondary education.
Katherine Ahlin, co-author and recent Master of Social Work graduate from University of Toronto, says, “It appears that these increasing educational opportunities continue to pay dividends more than half a century later. The short-term benefits of increasing educational attainment for income, productivity and the economy are well documented, but our research suggests the long-term benefits on later-life cognitive functioning are substantial. Our findings underline the importance of ensuring each generation has access to quality and affordable education.”
As for the other causes behind the decline, researchers aren’t sure. However, they believe possible contributing factors include improvements in nutrition, lower rates of smoking and air pollution, and the phase out of leaded gasoline.
Going forward, the team says they want to examine why men aren’t seeing as much of a decline in cognitive impairment as women. They will also be investigating whether these positive trends continue into the future.