A lot of people wear watches that count their every step as they try to move more.

Now, a new study finds that getting more of those steps each day, along with moderate-to-vigorous physical exercise, could cut the risk of dementia and thinking impairments for women.

For women aged 65 or older, each additional 31 minutes per day of moderate-to-vigorous physical activity was associated with a 21% lower risk of developing mild cognitive (thinking) impairment or dementia, according to the study led by researchers at the University of California, San Diego (UCSD). The risk was 33% lower with each additional 1,865 daily steps.

“Given that the onset of dementia begins 20 years or more before symptoms show, early intervention for delaying or preventing cognitive decline and dementia among older adults is essential,” said senior study author Andrea LaCroix, a professor at UCSD’s Herbert Wertheim School of Public Health and Human Longevity Science.

Much of past research on movement and sitting in relation to mild cognitive impairment and dementia has used self-reported measures rather than devices, noted first study author Steve Nguyen, a postdoctoral scholar at the School of Public Health.

For this study, the researchers included data from 1,277 women who were in Women’s Health Initiative ancillary studies that looked at memory, physical activity and heart health.

Study participants wore research-grade accelerometers (a device that measures motion). They were asked to go about their daily activities for up to seven days.

The women averaged 3,216 steps and 276 minutes in light physical activities, such as housework, gardening and walking, each day. They also averaged 45.5 minutes of moderate-to-vigorous physical activity, such as brisk walking, and 10.5 hours of sitting per day.

Higher amounts of sitting and prolonged sitting were not associated with higher risk of mild cognitive impairment or dementia, according to the report.

The findings were published online Jan. 25 in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association.

“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,” Nguyen said in a university news release.

“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,” he added.

Dementia affects more than 5 million people in the United States, according to the U.S. Department of Health and Human Services, and that number could double by 2050.

Women have a higher risk than men of developing memory and thinking issues, the study authors noted.

“Physical activity has been identified as one of the three most promising ways to reduce risk of dementia and Alzheimer’s disease,” LaCroix said. “Prevention is important because once dementia is diagnosed, it is very difficult to slow or reverse. There is no cure.”

More information

The U.S. Centers for Disease Control and Prevention has more on dementia.

SOURCE: University of California, San Diego, news release, Jan. 24, 2023