Medicine Physical activity can slow down the progression of Alzheimer's disease
Exercise reduces the risk of Alzheimer's. New data now shows that it is beneficial even if there are already harmful deposits in the brain.
03.11.2025, 17:00
SDA
According to the study, just a few thousand steps a day can lead to a slower progression of Alzheimer's disease. The analysis shows for the first time effects in people who already have Alzheimer's-typical changes in the brain, said Emrah Düzel from Magdeburg University Hospital, who was not involved in the study himself. "Here, physical activity appears to slow down the spread of these changes over the years and, in conjunction with this, protect mental performance."
The causes of Alzheimer's disease, in which nerve cells gradually die off, have not yet been clarified in detail. What is known is that diabetes, sleep disorders and depression are among the risk factors.
Physically active people are slower to develop symptoms
In physically active people with preclinical - i.e. still asymptomatic - Alzheimer's, a lower rate of cognitive decline has now been recorded than in physically inactive people. Just 3,000 steps a day can help to reduce the accumulation of damaging tau protein clumps in the brain. Between 5,000 and 7,500 steps have an even greater effect, as the team led by Wai-Ying Wendy Yau from Mass General Brigham in Boston reported in the journal "Nature Medicine".
The results confirm that lack of exercise is a risk factor for Alzheimer's disease, said Düzel, Director of the Institute for Cognitive Neurology and Dementia Research at the hospital. In general, physically active older people could preserve their brain substance better than physically inactive people.
Navigating, orienting, interacting
Nothing can be deduced from the study about the mechanism behind this. One possible effect could be that regular walking trains cognition: "People have to navigate, orient themselves and interact with their surroundings." Cardiovascular health is also trained. Finally, increased physical activity releases a number of blood-borne growth and protective factors that could have a positive effect on the brain and slow down the spread of tau.
For the study, the cognitive abilities and the presence of beta-amyloid plaques and tau fibrils in the brain of around 300 older adults were recorded at the beginning and then again several times. 88 of the test subjects initially exhibited preclinical Alzheimer's dementia: they did not yet have any symptoms, but already had an increased load of beta-amyloid plaques. At the beginning, the number of steps walked daily was measured, but there was no long-term recording of sporting activity.
The data showed that the tau protein, a marker of the progression of the disease, accumulated more slowly in the brain in physically active people - which explains the delayed cognitive decline, which in some cases lasted several years. People in the early stages of Alzheimer's disease can therefore significantly slow down its progression by getting plenty of regular exercise. "Every step counts - and even small increases in daily activity can add up to lasting changes in habits and health over time," says Yau.
More probably helps more
One shortcoming of the study was that the number of steps was only recorded once at the beginning, said Düzel. "We know little about how much the participants exercised in the years following the study." The researchers' conclusion that there was hardly any further improvement above a step count of 5,000 to 7,000 should be interpreted with caution. "Under no circumstances would I conclude that more exercise is not necessary." Intensive physical activity such as jogging or dancing could very likely trigger additional effects.
It can also be assumed that additional factors were relevant. "For example, in addition to physical activity, the fact that an increased number of steps leads to a more cognitively active lifestyle may play a role," explained Düzel. "Walking requires planning, orientation, memory and a number of other cognitive factors."
The physician advises people to take the results to heart and walk at least 5,000 to 7,000 steps a day. Where possible, these walks should be combined with exploring the surrounding area - and even new surroundings. A range of sports such as cycling, dancing or jogging could have additional effects due to their intensity and stimulation of the brain.
