Texas A&M study shows small, consistent physical activity can reduce dementia risk in older adults with mild cognitive impairment.
A new study from Texas A&M University suggests that even minimal exercise – just 20 minutes, twice a week – may help slow cognitive decline in older adults at risk of dementia.
Led by Jungjoo Lee at the Center for Community Health and Aging, the study analyzed nearly a decade of data from the Health and Retirement Study (2012–2020), tracking 9,714 adults aged 50 and above [1]. The research, published in the Journal of Physical Activity and Health, offers a clearer picture of how much movement is necessary to make a measurable impact on brain health.
“The benefits of exercise for this group have long been known, but by using a longitudinal study design and analyzing various levels of activity, we could determine the amount and duration needed to help prevent further decline,” said Lee.
Understanding mild cognitive impairment
Mild cognitive impairment (MCI) refers to noticeable changes in memory or thinking that do not yet interfere with daily life. While not everyone with MCI progresses to Alzheimer’s or other dementias, individuals with the condition are generally at higher risk.
Lee notes that outcomes vary: “Some with the condition stay stable or even improve over time, while others progress to dementia. Our age and how well our brain was working to begin with are factors. In addition, solving puzzles, spending time with others, and staying physically active may help slow down or even stop the slide.”
The link between activity and cognition
Researchers assessed cognitive function using three tests: memory recall of a 10-word list, working memory through repeated subtraction exercises, and attention/processing speed via backward counting tasks. They then correlated these measures with the participants’ engagement in 21 physical activities, ranging from walking to sports.
The study found that older adults who maintained moderate activity levels had a significantly lower chance of developing dementia over time. By contrast, those who were inactive saw little to no benefit.
“Older adults who maintained moderate levels of physical activity showed a significantly lower chance of developing dementia over time, while those who were less active saw little to no benefit,” said co-author Junhyoung Kim.
“This highlights the importance of regular movement – such as walking – as a simple and effective strategy to support brain health,” he added.
Other factors affecting dementia risk
The research also confirmed known risk modifiers: dementia risk increases with age, while higher levels of education and baseline cognitive function reduce risk. Interestingly, sex appeared to have no effect on dementia likelihood.
Lee emphasizes the broader implications, saying that “one out of every nine adults 45 and older in the United States say they experience confusion or memory loss that is getting worse, and that shows no signs of improving.”
“This study and future studies could help in the development of community-based, comprehensive activities for this growing population,” he emphasized.
Practical takeaways for older adults
For adults with MCI or those concerned about memory decline, the message is clear: small, consistent efforts matter. Even minimal weekly activity, two 20-minute sessions, can support cognitive function. Walking, light exercise and other moderate activities can be integrated into daily routines without needing a gym or specialised equipment.
The study underscores the need for accessible, community-supported programs that encourage sustained participation. With dementia cases projected to rise as populations age, simple interventions like these could have a meaningful public health impact.
[1] https://hrsdata.isr.umich.edu/data-products/2022-hrs-core
