If you’ve ever known someone with Alzheimer’s disease, you know how gradually—and devastatingly—it can take hold. It often starts with small lapses: misplacing keys, forgetting where they were driving. Over time, those slips can escalate to forgetting the names of loved ones. Given how heartbreaking the disease is, it’s no surprise people are eager to lower their risk of developing it in any way possible.
Previous research has shown that staying mentally active, exercising regularly, and eating a healthy diet rich in lean meats, fruits, and vegetables can help slow cognitive decline. Now, new findings suggest that even starting moderate exercise in midlife—about 150 minutes per week—may reduce amyloid buildup in the brain, a key marker of Alzheimer’s.
For the study, researchers analyzed data from 337 cognitively healthy adults, ages 45–65, most of whom had a family history of Alzheimer’s. Over a four-year period, participants reported their physical activity levels at two different points.
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The participants were divided into two groups—those who exercised for 150 hours per week and those who didn’t. They also underwent brain imaging to assess amyloid buildup (via PET scans) and cortical thickness (via MRI), both of which are associated with increased Alzheimer’s disease.
At the end of the study, the researchers had some pretty significant discoveries. Most notably, individuals who remained sedentary throughout the study had significantly lower cortical thickness in brain regions vulnerable to Alzheimer’s, along with higher levels of amyloid buildup—a hallmark of the disease.
On the other hand, participants who exercised some (even if it wasn’t the full 150 minutes recommended) showed measurable brain benefits.
This isn’t the first study that has linked physical activity to a decreased risk of Alzheimer’s disease. Another recent study from the Johns Hopkins Bloomberg School of Public Health found that as little as 35 minutes of moderate to vigorous physical activity per week was associated with a 41% lower risk of developing dementia.
Both studies suggest that doing something is far better than doing nothing at all when it comes to protecting your brain.