Study Links Midlife Activity Levels to Future Dementia Risk

But Najar did adjust results to take into account things like high blood pressure, cigarette smoking and diabetes, which could have affected the participants’ individual risks of dementia. She and her team also ran the results again after excluding women who developed dementia about halfway through the study to rule out the possibility that those women started the study in a very early stage of dementia that might have already been limiting their participation in activities.

For expert tips to help feel your best, get AARP’s monthly Health newsletter.

While the results indicate that levels of both physical and mental activities could affect your cognitive health later — Najar noted that physical activity may lower your chances of vascular dementia in particular — the study’s conclusions also show how the two effects are distinct. As Najar put it, “We found that mental activities in midlife such as reading a book, doing crossword puzzles, singing or visiting concerts, to name a few, reduced the risk of dementia and Alzheimer’s disease, regardless of how physically active the women were. While physical activity in midlife reduced the risk of more vascular forms of dementia, regardless of how mentally active the women were.”

The observational research reinforces the results of other recently published work. At the University of Washington, researchers looked at how having years of exercise under one’s belt might help fend off brain damage in people who carry a gene that increases their risk of Alzheimer’s. Experts say the continuing research challenge is to find the physical pathway connecting such lifestyle factors in midlife to specific protective effects in the brain. Teasing out what affects the cognitive changes associated with aging vs. what prevents pathologies such as Alzheimer's — and how different those two things are — are also big questions. 

If not a new message, today's study results offer “a confirmatory message, and more evidence about the validity of the notion of being cognitively and physically active to prevent cognitive effects of aging,” says neurologist Ron Petersen, director of the Mayo Clinic Alzheimer's Disease Research Center and the Mayo Clinic Study of Aging in Rochester, Minn. He notes that AARP’s own Global Council on Brain Health, of which he’s a member, recently found enough scientific consensus to recommend that middle-aged people pursue both physical and mental activities for the express purpose of improving their future cognitive health.