Findings published in Neurology on July 14 analyzed nearly 2,000 patients about 80 years old on average and free of dementia at the study start. During seven years of follow-up with annual exams and cognitive tests, some 457 people about 90 years old on average developed dementia, or “impaired ability to remember, think, or make decisions that interferes with doing everyday activities,” according to the Centers for Disease Control and Prevention (CDC).
Study participants answered questions about cognitive activity when they were kids, adults and in middle age, and also how often they read books, played board games or puzzles over the year. Respondents who were the most mentally active typically developed dementia by age 94, compared to those least mentally active who usually developed dementia by 89, or some five years sooner. The difference upheld after researchers controlled for other factors potentially confounding dementia risk like sex and education, according to a related news release.
“The good news is that it’s never too late to start doing the kinds of inexpensive, accessible activities we looked at in our study,” study author Robert S. Wilson, PhD, of Rush University Medical Center in Chicago, said in a news release posted by the American Academy of Neurology. “Our findings suggest it may be beneficial to start doing these things, even in your 80s, to delay the onset of Alzheimer’s dementia.”
To confirm their findings, the team studied brain tissue of 695 people who died during the study period, and looked for markers associated with Alzheimer’s disease, like harmful plaque buildup of the amyloid and tau proteins. Researchers found no link between how active the deceased patients had been cognitively and markers of Alzheimer’s disease and related disorders in their brains.
“Our study shows that people who engage in more cognitively stimulating activities may be delaying the age at which they develop dementia,” Wilson said. “It is important to note, after we accounted for late life level of cognitive activity, neither education nor early life cognitive activity were associated with the age at which a person developed Alzheimer’s dementia. Our research suggests that the link between cognitive activity and the age at which a person developed dementia is mainly driven by the activities you do later in life.”