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By Juliette Frank

Aging is a natural process that can look and feel different for everybody; our brains and bodies change and often slow down which can result in symptoms of mild cognitive decline or dementia. Approximately 12% to 18% of people aged 60 or older are living with mild cognitive impairment (MCI) and an estimated 10% to 15% of individuals living with MCI develop dementia each year. Dementia is a group of neurological conditions characterized by deficits in thinking, remembering, and reasoning. The severity of these deficits interferes with typical daily functioning and is more pronounced than the decline in cognitive function observed during healthy aging. MCI is a condition involving deficits in thinking or memory that are, unlike dementia, not severe enough to interfere with daily activities. MCI is often an intermediate phase between typical aging and dementia, but individuals with MCI do not always develop dementia. Although aging is inevitable, there are effective strategies that can help prevent or delay these symptoms.

“Currently, there are no effective treatments for MCI and dementia, but there are effective strategies to help protect brain health and reduce risk factors for cognitive decline.”

Currently, there are no effective treatments for MCI and dementia, but there are effective strategies to help protect brain health and reduce risk factors for cognitive decline. Maintaining a healthy lifestyle is a strategy that is widely accepted as a promising intervention treatment, but much of the evidence has been self-reported data which only ensures limited accuracy. A recent study published in January used accelerometers to accurately measure physical activity levels that proved that moderate-to-vigorous physical activity and daily steps, but not light physical activity and sitting, were associated with a lower risk of cognitive decline in older women. The study specifically distinguished that the level of intensity of the activity is significant and that light physical activity and sitting are not effective in attenuating risk factors for dementia. Raphael Wald, PsyD, a neuropsychologist at Baptist Health Marcus Neuroscience Institute added, “The study also shows that there is no real cap on the cognitive gains that can be had from physical activity. The more you can safely do the more it decreases your risk for cognitive decline.” The study found that including 31 minutes of additional daily moderate-to-vigorous physical activity was associated with a reduction in the risk of MCI or dementia by 21%. Similarly, including an additional 1,865 steps in the daily routine was associated with a 33% lower risk of cognitive decline.

“Researchers found that moderate to vigorous physical activity and daily steps were associated with lower risk of MCI and dementia.”

The study, supported by the Alzheimer’s Association, specifically focused on women due to their elevated risk of dementia with a 20% lifetime risk compared to men who average a 10% risk. The study worked with the Women’s Health Initiative, which is a long-term study focused on preventing chronic conditions in postmenopausal women and one of the largest women’s health projects ever launched in the United States, having enrolled more than 161,000 women at 40 clinical centers. The researchers recruited ~1,200 women from the Women’s Health Initiative with an average age of 82 to participate in this study. The women did not show symptoms of MCI or any cognitive decline at the onset of the study. The researchers used hip accelerometers to accurately measure the levels of activity of each participant, including light, moderate and vigorous movements as well as sitting or reclining. Researchers monitored the participants over an average follow up of 4.2 years during which 267 of the participants were diagnosed with mild cognitive impairment or developing dementia. Researchers found that moderate to vigorous physical activity and daily steps were associated with lower risk of MCI and dementia.

“Further analysis revealed that only moderate-to-vigorous intensity steps were associated with a lower risk of MCI…”

The participants who fell in the highest quartile of moderate-to-vigorous physical activity levels (average of 61 minutes daily) were at a 36% lower risk of MCI than those in the lowest quartile (average of 23 minutes/day of moderate-to-vigorous physical activity), although the dementia risk was not statistically significant. However, those in the highest quartile of daily step count (minimum 4050 steps/day) were at a 64% lower risk of MCI and 52% lower risk of dementia than those in the lowest quartile (under 1867 steps/day). Further analysis revealed that only moderate-to-vigorous intensity steps were associated with a statistically significant lower risk of MCI, whereas low-intensity steps had no impact on MCI and dementia symptoms, making it clear that intensity level of the activity matters.

“The results from this study reiterate and emphasize the already known benefits of physical activity, especially more intensive workouts, on overall health and well-being.”

Several other large studies have looked at physical activity and dementia risk, but this study is significant in that the investigators focused specifically on women who are at the highest risk of dementia. Although the study produced some of the most accurate results due to their use of accelerometers to measure physical activity levels, the researchers acknowledged that the 4.2 year follow-up period was relatively short considering symptoms of dementia can develop over a 20-year period. It is also worth noting the lack of diversity amongst the participants, specifically the disproportionate amount of non-Black and Hispanic/Latinx women gives further need for a larger, more representative study in the future. Overall, the results from this study reiterate and emphasize the already known benefits of physical activity, especially more intensive workouts, on overall health and well-being.

Juliette Frank is a recent UCLA graduate with a degree in Public Affairs and Food Studies. Her interests include the interrelation between food systems, digestive health, and the environmental impacts of food production. She believes the intersectionality of food has long been overlooked and is the key connection between the health of humans, animals, and the environment. She is passionate about reforming the food system as It is one of the most accurate determinants of the health inequities present in our society, making it one of the most effective places to start in healing the people and the planet from a long history of damage.