Walking a Little Each Day Can Slow Down Alzheimer’s Disease

Being physically active is good for all parts of you, including your brain. The latest research shows that it may help slow the progression of Alzheimer’s disease in people at higher risk of developing this neurodegenerative disease.

Other recent studies have established this link between exercise and better cognitive health, and these findings suggest that people with Alzheimer’s disease who are more physically active may be able to slow cognitive decline and memory problems. But these studies are limited by a number of factors discussed in the last analysis.

In the present study, published in Natural medicinescientists used a more objective method to measure physical activity in people at higher risk of developing Alzheimer’s disease and tracked signs of the disease using advanced imaging techniques to show that those who were more active reduced their risk of cognitive decline by up to 54%. They also found slower cognitive and functional decline, starting at around 3,000 steps per day for relatively sedentary people.

The study looked at nearly 300 people who were still cognitively normal but were at higher risk of developing Alzheimer’s disease because their brain scans showed signs of amyloid plaques, clumps of proteins characteristic of Alzheimer’s disease. When amyloid plaques build up, they begin to damage neurons involved in higher thinking and memory and eventually lead to the buildup of another protein, tau, which is toxic to nerve cells. In the study, researchers, led by Dr. Wai-Ying Wendy Yau, a neurologist at Mass General Brigham, tracked the transition from amyloid to tau as an indicator of disease progression for about nine years on average for participants.

“What we show is that amyloid and physical activity seem to work together to impact cognitive and tau decline,” says Yau. “And in people who have high levels of amyloid in the brain and are at higher risk of developing tau and cognitive decline, but are still asymptomatic, our study shows that high levels of physical activity can slow disease progression.”

Learn more: Changing Your Diet and Lifestyle Can Slow Alzheimer’s Disease

Although the people’s amyloid levels did not change significantly during the study period, their accumulation of tau, an indicator of Alzheimer’s progression, differed depending on how physically active the people were. This resulted in slower cognitive decline, as measured by a number of cognitive and functional tests.

Those who logged the most steps on average daily, as measured by a pedometer, reduced their rate of cognitive decline by up to 54% compared to those who were inactive. Those who were most active also saw similar benefits in measures of functional decline, which focus more on tasks such as the ability to dress themselves and engage in daily activities. Among the fittest people, this type of decline slowed by up to 51% compared to inactive people.

“Amyloid is a way to assess whether a person is on the trajectory of Alzheimer’s disease,” says Dr. Jasmeer Chhatwal, associate professor of neurology at Mass General Brigham and Harvard Medical School and senior author of the study. “But even with this high risk factor for amyloid, these results suggest that physical activity may modulate the link between amyloid and tau. This is a critical component that impacts cognitive performance, as tau appears to be closely associated with cognitive performance.”

Learn more: The surprising power of a 10-minute walk

The effect was particularly strong among those who were inactive and began walking daily. That’s encouraging, Chhatwal says, since these are the people who are at greatest risk of developing rapid cognitive decline.

The study showed that the benefits of exercise plateau, so after about 5,000 to 7,500 steps per day, the slowing decline levels off. Still, he and Yau say the findings should encourage people that even relatively little activity can be beneficial for the brain, especially for those who are sedentary.