Being physically active is good for every part of you—including your brain. The latest research shows that it can help slow the progression of Alzheimer’s disease in people who are at higher risk of developing the neurodegenerative condition.
Other recent studies have made this connection between exercise and better cognitive health, and those results suggest that people with Alzheimer’s disease who are more physically active may be able to slow down cognitive decline and memory issues. But those studies are limited by a number of factors that the latest analysis addressed.
In the current study, published in Nature Medicine, scientists used a more objective way to measure physical activity among people at higher risk of Alzheimer’s 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 saw slower cognitive and functional decline beginning at around 3,000 steps per day for people who were relatively sedentary.
The study included nearly 300 people who were still cognitively normal but at higher risk of developing Alzheimer’s because their brain scans showed evidence of amyloid plaques, the clumps of protein that are the hallmark of Alzheimer’s. When amyloid plaques build up, they start to damage neurons involved in higher thinking and memory and eventually lead to the accumulation of another protein, tau, that is toxic to nerve cells. In the study, the researchers, led by Dr. Wai-Ying Wendy Yau, a neurologist at Mass General Brigham, followed the transition from amyloid to tau as an indicator of advancing disease for about nine years on average for participants.
“What we show is that amyloid and physical activity seem to be working together to impact tau and cognitive decline,” says Yau. “And in people who have high levels of amyloid in their 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 may be able to slow down disease progression.”
Read More: Changing Your Diet and Lifestyle May Slow Down Alzheimer’s
While people’s amyloid levels did not change significantly over the study period, their accumulation of tau, an indicator of Alzheimer’s progression, differed depending on how physically active people were. That translated into slower cognitive decline as measured by a number of cognitive and functional tests.
Those who recorded the most steps on average daily, measured by a pedometer, lowered their rate of cognitive decline by up to 54% compared to those who were inactive. Those who were most active also saw similar benefits on measures of functional decline, which focus more on tasks such as being able to dress and take care of daily activities. In the fittest people, that type of decline slowed by up to 51% compared to people who were inactive.
“Amyloid is a way of assessing whether somebody is on the Alzheimer’s disease trajectory,” 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 that high risk factor of having amyloid, these results suggest that physical activity can modulate the connection between amyloid and tau. That’s a critical piece that impacts cognitive performance because tau seems to be tightly associated with cognitive performance.”
Read More: The Surprising Power of a 10-Minute Walk
The effect was especially strong among those who were inactive and started walking daily. That’s encouraging, says Chhatwal, since these are the people who are at highest risk of developing rapid cognitive decline.
The study showed that the benefits of exercise do plateau, so after about 5,000 to 7,500 steps a day, the slowing of decline leveled off. Still, he and Yau say that the findings should encourage people that even relatively small amounts of activity can benefit the brain, especially for those who are sedentary.
Yau and Chhatwal stress that the findings do not suggest that physical activity is the cure-all for Alzheimer’s. Instead, the results make a strong case that exercise should be a part of any prevention strategy for people who already have amyloid in the brain but who do not yet show symptoms of the disease. Combining recent anti-amyloid medications with physical activity, for example, could be a way to hold off progression of Alzheimer’s. And with advances in detecting signs of amyloid—now with PET brain scans and increasingly with improved blood tests—more people will become aware that they are at risk for the disease.
“These results empower people and let them know that there is not an inevitable connection between being diagnosed with Alzheimer’s and rapid cognitive decline,” says Chhatwal. “These findings reinforce that lifestyle factors are not necessarily just working around the edges of larger Alzheimer’s disease processes but that they can have a profound effect on how amyloid leads to cognitive decline.”
The post Walking a Little Each Day Can Slow Down Alzheimer’s Disease appeared first on TIME.
