A sign in everyday life may indicate memory decline after 50

The conclusion is part of a study published in JAMA Network Open that analyzed data from 2,529 adults aged 50 and over, living in England. The researchers tracked the participants' cognitive development for 17 years and then objectively measured how much time they spent moving, sitting or sleeping.

The results reinforce an issue that has been gaining ground in research on aging: the relationship between physical activity and brain health can work both ways. Although previous studies associate a more active routine with better cognitive outcomes, memory loss can also contribute to a person becoming progressively less active.

How did the study track participants' memory?

The researchers used data from the English Longitudinal Study of Aging, a long-term study of adults living in England.

Between 2002 and 2019, participants underwent periodic assessments of memory and verbal fluency. Memory was measured by immediate and delayed word recall tests, while verbal fluency was assessed by a task in which volunteers needed to name animal names.

With this information, the team was able to identify different cognitive trajectories over 17 years, distinguishing people with more favorable evolution from those who showed a more pronounced drop in performance.

In a later stage, between 2021 and 2023, participants wore accelerometers on their wrists for eight consecutive days. The devices recorded the time dedicated to light physical activity, moderate or vigorous exercise, sedentary behavior and periods of sleep.

Worsening memory was associated with less movement

The main difference appeared in light physical activities.

Participants with a more favorable memory trajectory did, on average, 14 minutes more of light physical activity per day than those whose memory had a less favorable evolution. During the week, this difference corresponds to approximately 1.6 hours more movement.

Among those over 70 years of age, the gap became even more evident. In this group, a more favorable memory trajectory was associated with about 20 additional minutes of light activity per day, equivalent to approximately 2.3 hours per week.

Light physical activity does not necessarily mean going to a gym. Calm walks, household chores and other common routine movements fall into this category.

More sitting time also appeared in the survey

The researchers observed the opposite behavior in relation to a sedentary lifestyle. People with a worse memory trajectory spent more time sitting or lying down while they were awake.

When comparing the extremes of memory trajectories, those with better cognitive results recorded approximately 12 minutes less of sedentary behavior per day. Among participants over 70 years old, the difference reached around 16 minutes per day.

The differences related to moderate or vigorous exercise were much smaller. The same happened with sleep time. The clearest association was observed between memory, light physical activity and sedentary behavior.

Verbal fluency showed a similar trend, but the differences in movement were smaller than those found in memory tests.

Could a reduction in activities be a sign to watch out for?

The results suggest that becoming less active as the years go by should not always be interpreted simply as a natural consequence of age or physical limitations.

According to the authors, cognitive changes can influence the ability to initiate, plan and maintain daily activities. Thus, the gradual reduction in movement may, in some cases, accompany changes in cognitive function.

This does not mean, however, that a person who spends more time sitting is necessarily developing dementia or some other cognitive problem. The study identified an association, not a direct cause-and-effect relationship.

The researchers themselves highlight that other factors can influence both cognition and the level of physical activity. The sample was also predominantly white, and movement measurement occurred during the period of the Covid-19 pandemic, although not during national lockdowns.

Exercise and brain health can be linked both ways

The research adds a new perspective to the debate about exercise and brain aging. Instead of just considering that physical activity can influence cognition, the authors point out that cognitive changes can also modify the amount of movement performed in everyday life.

For researchers, understanding this relationship is important because a drop in daily activity may reflect functional changes that deserve attention, especially among older people.

The study was published in May 2026 in JAMA Network Open and concluded that less favorable memory trajectories were later associated with less light physical activity and more sedentary time, an effect that was more pronounced among adults over 70 years of age.

Fever with neurological changes requires immediate care

Meningitis and encephalitis are among the most serious infections of the central nervous system. Meningitis causes inflammation of the meninges ? membranes that surround the brain and spinal cord ?, while encephalitis directly affects brain tissue.