More than 22,500 adults were tracked using their Fitbit data, then for about five years using their medical records. Researchers observe a link between low activity and neurological health, without demonstrating that walking more would directly prevent these diseases.
Fewer steps, more neurological diagnoses
A step counter doesn’t tell the whole story. But when activity declines sustainably, day after day, this development may merit attention. This is what an American study presented at the 151st annual meeting of the American Neurological Association explored.
The researchers analyzed data from 22,517 adults aged 40 or overfrom the American research program All of Us. Participants had at least 180 days of Fitbit data for an initial year. Their medical records were then followed for approximately five years to identify new diagnoses of dementia, Parkinson’s disease, stroke or transient ischemic attack (TIA).
Three groups were distinguished: around 4,800 steps per day for the least active, 8,300 for the intermediate group and 12,600 for the most active.
A total of 343 participants received one of the diagnoses studied. The rate reached 3.81 events per 1,000 person-years among the least active, compared to 2.12 among the most activea rate approximately 80% higher.
A notable difference, but which does not mean that walking less causes these diseases. To understand this link, the researchers also looked at the health status of the participants.
Diabetes, hypertension, depression: the brain does not live in isolation
Less active people had more risk factors. Their average body mass index was 32.1, compared to 26.5 among the most active. Diabetes affected 5.6% of the least active group, compared to 2% of the most active group. Hypertension was also more common: 13.4% versus 9.2%.
Depression presented a particularly marked gap:
8.6% among the least active, compared to 3.1% among the most active. Researchers have identified it as the predictive factor most strongly associated with later neurological diagnoses, while recalling that it can also constitute an early symptom of certain diseases, notably dementia and Parkinson’s.
“Low activity and conditions such as obesity, diabetes, high blood pressure and depression often go hand in hand and are part of a broader health picture.”explains Dr Meet Popatbhai Kachhadia, first author of the study, in the press release from the American Neurological Association.
He points out that data from connected watches could help identify people who need earlier support for their weight, blood pressure, blood sugar or mental health.
Moreover, when the researchers took into account more health factors in their statistical analysis, the association between low activity and neurological diagnoses was no longer statistically significant according to the conventional threshold. Part of the observed link could therefore be explained by these factors.
Should you aim for 5,000 or 8,000 steps per day?
The study does not allow you to set an ideal number of steps to protect your brain. Observational, it highlights an association without proving that increasing activity directly prevents dementia, Parkinson’s disease or stroke. The data additionally comes from Fitbit users and diagnoses recorded in medical records.
However, one result deserves attention: people taking around 8,000 steps per day had a lower rate of diagnoses than the least active group.
“Everyone should get into the habit of regular physical activity, setting realistic and sustainable goals to improve their health.”recommends Dr. Marc A. Swerdloff, co-author of the study. “People who took about 8,000 steps per day had significantly lower rates of neurological disease than the least active group. It’s a realistic goal (…) No one needs to reach 12,000 steps.”
In France, the recommendations favor the duration and intensity of the effort: in adults, they recommend in particular 150 to 300 minutes of moderate-intensity physical activity per week. The number of steps remains a benchmark, not a universal prescription.
A lasting decline in activity: a signal to listen to
A meter that stays low for months may reflect persistent fatigue, pain, low mood, or difficulty moving around. If this drop is unusual, it may be an opportunity to talk to your doctor and take stock of your overall health.
As Dr. Kachhadia summarizes in the release, “the amount of movement over a year can provide insight into overall brain and body health“. Connected watches could thus contribute, in the long term, to identifying certain developments requiring medical attention. But additional research will be necessary to clarify their interest.
A low step counter is neither a diagnosis nor an individual prediction. The goal is not to chase a number, but to move more at your own pace and not neglect a lasting change in your habits.
On the other hand, sudden weakness on one side of the body, sudden difficulty speaking, deformation of the mouth or sudden loss of vision can signal a stroke: immediately call 15 or 112.