BOSTON, Aug. 29 (UPI) -- The use-it-or-lose-it theory for preventing age-related dementia conditions is gaining strength as a large review of studies suggests cognitive activity may delay their onset.
Engaging in social activities, reading and playing games appears to help slow the development of Alzheimer's disease and other dementia-type conditions, even when considering for other health issues such as depression or socioeconomic conditions, researchers at Harvard University report in a study published in the journal Epidemiology.
Recent studies have shown that staying mentally active may delay the conditions but the researchers were unsure whether the effects seen in previous studies were actual improvements in condition, or just appeared that way because participants had been receding from engaging in cognitive activity.
While researchers involved with the new study are not completely convinced, they say the evidence shows re-engaging cognitively certainly does not have a downside.
"Cognitive activity looks like it may offer some modest protection, and based on our bias analysis, I am somewhat less skeptical than I was previously," Dr. Deborah Blacker, a professor of epidemiology at the Harvard T.H. Chan School of Public Health, said in a press release. "But remember that any impact will be relative, not absolute. I typically advise people to engage in cognitive activities that they find interesting and enjoyable for their own sake. There is no evidence that one kind of activity is better than another, so I would advise against spending money on programs claiming to protect against dementia."
For the study, the researchers analyzed data on 13,939 participants of 12 previous studies, including 1,663 cases of dementia and 565 cases of Alzheimer's disease.
While most of the studies showed increasing cognitive activity later in life was linked to lower Alzheimer's disease or other dementia disease, the researchers conducted a bias analysis to explore the potential role of other unmeasured factors.
Other factors were generally found not to increase the apparent effects of increasing cognitive activity, the researchers report. But they are also unsure whether reductions in cognitive activity during the slow mental decline as Alzheimer's disease sets in created the illusion of efficacy with increased activity.
Longer clinical trials, with longer term efforts at preventive cognitive activity, will be needed to fully support previous findings, the researchers say, but that it appears there is some benefit to engaging in thought-provoking behaviors.
"Our paper lends support to a potential role for late-in-life cognitive activity in prevention of Alzheimer's disease," Blacker, lead author of the study, said. "While it is possible that socioeconomic factors such as educational level might contribute to the association between cognitive activity and reduced risk, any bias introduced by such factors is probably not strong enough to fully account for the observed association."