Walking 3,000 or more steps a day may slow the progression of Alzheimer’s disease, a study says

Even modest amounts of daily exercise may slow the progression of Alzheimer’s disease in older people at risk of developing the condition, researchers said.

People are often encouraged to take 10,000 steps a day as part of a healthy routine, but scientists have found that 3,000 steps or more appears to delay the brain changes and cognitive decline that Alzheimer’s patients experience.

The results of the 14-year study showed that cognitive decline was delayed by an average of three years in people who walked from 3,000 to 5,000 steps per day, and by seven years in those who walked from 5,000 to 7,000 steps per day.

“We encourage older adults at risk for Alzheimer’s disease to consider making small changes to their activity levels, to build sustainable habits that protect or benefit their brains and cognitive health,” said Dr. Wei-Ying Yao, first author of the study at Mass General Brigham Hospital in Boston.

Dementia affects an estimated 50 million people worldwide, with Alzheimer’s disease being the most common cause. In the United Kingdom, more than 500,000 people suffer from Alzheimer’s disease. This condition is associated with the accumulation of two toxic forms of proteins in the brain: amyloid beta plaques and tau tangles.

Yao and her colleagues analyzed data from 296 people between the ages of 50 and 90 who did not have cognitive impairment at the start of the study. The data included annual cognitive assessments, the number of steps measured by pedometers, and PET imaging to detect levels of amyloid and tau in the volunteers’ brains.

People who initially had little amyloid in the brain showed very little cognitive decline or buildup of tau protein over the course of the study. The risk of developing Alzheimer’s disease was greater for those with higher amyloid levels at baseline, and among them, higher step counts were associated with slower rates of cognitive decline and delayed accumulation of tau proteins. The researchers said that tau protein accumulation and cognitive decline were much faster in sedentary individuals Report in the journal Nature Medicine.

While scientists cannot rule out reverse causation, as early brain changes in Alzheimer’s disease cause people to walk less in old age, the data suggest that physical activity is protective. “We need randomized clinical trials to prove cause and effect, but it is very encouraging that physical activity may help turn someone’s course around,” Yao said. “If they have amyloid, they may have a slower rate of decline if they are more physically active.”

It’s unclear how exercise might help, but physical activity improves blood flow, reduces inflammation and raises levels of certain hormones and growth factors, all of which may play a role. “In terms of potential mechanisms, this is the million-dollar question that we want to look at in future studies,” Yao said.

Dr Julia Dudley, from Alzheimer’s Research UK, said: “The results suggest that even a modest amount of walking each day, around 5,000 steps, is associated with slower buildup of tau protein in the brain, one of the main drivers of Alzheimer’s disease. This gives us a clearer picture of how daily activity supports brain health and influences the underlying causes of Alzheimer’s disease.”

“More research, including clinical trials, is needed to know the direct impact of physical activity on preventing and slowing the progression of dementia and on the underlying causes of the disease. But studies like this reinforce that simple changes to our lifestyle can help keep our brains healthy for longer.”