Summary: Older women who walked or did moderate to vigorous exercise every day had a reduced risk of developing mild cognitive impairment and dementia.
According to a new study conducted by the Herbert Wertheim School of Public Health and Human Longevity Science at the University of California, San Diego.
In the January 25, 2023 online edition of Alzheimer’s and dementia: the journal of the Alzheimer’s Association, the team reported that, in women aged 65 or older, every additional 31 minutes per day of moderate-to-vigorous physical activity was associated with a 21% lower risk of developing mild cognitive impairment or dementia. The risk was also 33% lower with each additional 1,865 daily steps.
“Given that the onset of dementia begins 20 years or more before the onset of symptoms, early intervention to delay or prevent cognitive decline and dementia in older adults is essential,” said the lead author. Andrea LaCroix, Ph.D., MPH, professor emeritus in the Herbert Wertheim School of Public Health and Human Longevity Science at UC San Diego.
Although there are several types, dementias are a debilitating neurological condition that can lead to loss of memory, ability to think, problem solve or reason. Mild cognitive impairment is an early stage of memory loss or thinking problems that is not as severe as dementia.
According to the US Department of Health and Human Services, dementia affects more than 5 million people in this country. This number is expected to double by 2050.
More women live with it and are at higher risk of developing dementia than men.
“Physical activity has been identified as one of the three most promising ways to reduce the risk of dementia and Alzheimer’s disease. Prevention is important because once dementia is diagnosed, it is very difficult to slow or reverse it. There is no cure,” LaCroix said.
However, because few large studies have examined device-based measures of movement and sitting in relation to mild cognitive impairment and dementia, much of the published research on associations between activity physical and sedentary behavior with cognitive decline and dementia is based on self-reported measures, said first author Steven Nguyen, Ph.D., MPH, postdoctoral fellow at the Herbert Wertheim School of Public Health.
For this study, researchers sampled data from 1,277 women in two Women’s Health Initiative (WHI) ancillary studies – the WHI Memory Study (WHIMS) and the Objective Physical Activity and Cardiovascular Health (OPACH) study. . The women wore research-grade accelerometers and performed their daily activities for up to seven days to get accurate measurements of physical activity and sitting.
Activity trackers showed the women averaged 3,216 steps, 276 minutes of light physical activity, 45.5 minutes of moderate-to-vigorous physical activity and 10.5 hours of sitting per day. Examples of light physical activity might include housework, gardening, or walking. Moderate to vigorous physical activity can include brisk walking.
The study results also showed that a greater amount of sitting and prolonged sitting was not associated with a higher risk of mild cognitive impairment or dementia.
Together, this information has clinical and public health importance because there is little published information on the amount and intensity of physical activity needed to reduce dementia risk, Nguyen said.
“Older people can be encouraged to increase their movement to at least moderate intensity and to take more steps each day to reduce the risk of mild cognitive impairment and dementia,” Nguyen said.
“The results for steps per day are particularly remarkable because steps are being recorded by a variety of wearable devices increasingly worn by individuals and could be easily adopted.”
The authors said further research is needed among large, diverse populations that include men.
Co-authors include: John Bellettiere, UC San Diego; Kathleen M. Hayden and Stephen R. Rapp, Wake Forest University School of Medicine; Chongzhi Di, Fred Hutchinson Cancer Center; Priya Palta, Columbia University Irving Medical Center; Marcia L. Stefanick, Stanford University School of Medicine; JoAnn E. Manson, Harvard Medical School; and Michael J. LaMonte, University at Buffalo – SUNY.
Funding: This research was funded, in part, by the National Institute on Aging (P01 AG052352, 5T32AG058529-03) and the National Heart, Lung, and Blood Institute (R01 HL105065). The Women’s Health Initiative was funded by the National Heart, Lung, and Blood Institute (75N92021D00001, 75N92021D00002, 75N92021D00003, 75N92021D00004, 75N92021D00005).
About this exercise, news on aging and dementia research
Author: Yadira Galindo
Contact: Yadira Galindo – UCSD
Picture: Image is in public domain
Original research: Access closed.
“Accelerometer-measured physical activity and sitting posture with mild cognitive impairment or probable dementia in older women” by Andrea LaCroix et al. Alzheimer’s and dementia
Physical activity measured by accelerometer and sitting position with mild cognitive impairment or probable dementia in older women
Physical activity (PA) is prospectively inversely associated with dementia risk, but few studies have examined accelerometer measures of PA and sitting with mild cognitive impairment (MCI) and risk of dementia. dementia rigorously judged.
We examined associations between accelerometer measurements (PA and sitting) and MCI incident/probable dementia in the Women’s Health Initiative (not = 1277; average age = 82 ± 6 years)
During a median follow-up of 4.2 years, 267 probable cases of MCI/dementia were identified. Adjusted Cox regression RRs (95% CI) in min/d quartiles of moderate-to-vigorous PA (MVPA) were 1.00 (baseline), 1.28 (0.90 to 1.81), 0.79 (0.53 to 1.17) and 0.69 (0.45 to 1.06); Trend P = 0.01. Adjusted RRs (95% CI) for step/d quartiles were 1.00 (baseline), 0.73 (0.51 to 1.03), 0.64 (0.43 to 0.94 ) and 0.38 (0.23 to 0.61); Trend P < 0.001. The HR (95% CI) for each increment of 1-SD in MVPA (31 min/d) and steps/d (1865) was 0.79 (0.67 to 0.94) and 0.67 ( 0.54 to 0.82), respectively. Sitting was not associated with probable MCI/dementia.
The results suggest that ≥ moderate intensity PA, especially walking, is associated with a lower risk of MCI and dementia.