SAN DIEGO — If you want to keep your mind sharp during old age, just keep moving. Researchers from UC San Diego say women over the age of 65 are less likely to develop mild cognitive impairment or dementia if they walk more and engage in moderate-to-vigorous physical activity on a daily basis. More specifically, the study finds that for every additional 31 minutes older women spend engaging in moderate-to-vigorous exercise, they lower their risk for cognitive decline by 21 percent.
Moreover, those same risk profiles dropped by 33 percent with each additional 1,865 daily steps each day.
“Given that the onset of dementia begins 20 years or more before symptoms show, the early intervention for delaying or preventing cognitive decline and dementia among older adults is essential,” says senior study author Andrea LaCroix, Ph.D., M.P.H., Distinguished Professor at the Herbert Wertheim School of Public Health and Human Longevity Science at UC San Diego, in a university release.
Dementia can manifest itself in a number of different forms, but doctors consider all varieties a debilitating neurological condition that can result in the loss of one’s memory, as well as the capacity to think clearly, solve problems, or evoke basic reasoning. Mild cognitive impairment, meanwhile, is one of the earlier stages of memory loss or thinking problems — although it’s not as severe as dementia.
There’s little concrete data on how exercise and sitting affects dementia
According to the CDC, roughly six million Americans currently live with dementia. Estimates predict that the worldwide number of cases will triple by 2050. Notably, dementia rates tend to be much higher among women than men.
“Physical activity has been identified as one of the three most promising ways to reduce risk of dementia and Alzheimer’s disease. Prevention is important because once dementia is diagnosed, it is very difficult to slow or reverse. There is no cure,” Prof. LaCroix explains.
However, since few large-scale studies have utilized objective devices to measure movement and sitting habits in relation to cognitive impairment and dementia, study authors say much of the published research on this topic relies on subjective self-reported measures.
This project featured sampled data from 1,277 women collected as part of two Women’s Health Initiative (WHI) ancillary studies: the WHI Memory Study (WHIMS) and the Objective Physical Activity and Cardiovascular Health (OPACH) Study. These women wore research-grade accelerometers while going about their usual routines for a period of up to seven days.
Does sitting too much really lead to cognitive decline?
Those activity measurements revealed the women averaged 3,216 steps, 276 minutes of light physical activities, 45.5 minutes of moderate-to-vigorous physical activity, and 10.5 hours of sitting each day. Examples of light physical activity included walking, gardening, or housework. Brisk walking, meanwhile, would classify as a moderate-to-vigorous physical activity.
Notably, researchers add that more time spent sitting and prolonged sitting habits did not have an association with a higher risk of mild cognitive impairment or dementia.
All in all, considering there is woefully little information regarding the amount and intensity of physical activity required to lower one’s dementia risk, first study author Steven Nguyen, Ph.D., M.P.H., postdoctoral scholar at the Herbert Wertheim School of Public Health, believes these findings hold valuable clinical and public health importance.
“Older adults can be encouraged to increase movement of at least moderate intensity and take more steps each day for a lower risk of mild cognitive impairment and dementia,” Dr. Nguyen concludes. “The findings for steps per day are particularly noteworthy because steps are recorded by a variety of wearable devices increasingly worn by individuals and could be readily adopted.”
Moving forward, study authors say further research is necessary which covers a larger sample group that includes men.
The study is published in the journal Alzheimer’s & Dementia.