A new study suggests that increasing physical activity between the ages of 45 and 65 could help protect the brain and reduce the risk of developing Alzheimer’s disease.
The research, published in the journal Alzheimer’s & Dementia, shows that not only does regular exercise benefit brain health—but that even small increases in activity over time can have a meaningful effect.
The study was led by researchers from the Barcelona Institute for Global Health (ISGlobal) and the Barcelonaβeta Brain Research Center (BBRC), both supported by the “la Caixa” Foundation. Their work highlights the growing importance of physical activity as a strategy to prevent Alzheimer’s, especially among middle-aged adults with a family history of the disease.
According to estimates, about 13% of Alzheimer’s cases worldwide are linked to physical inactivity. The World Health Organization (WHO) recommends 150–300 minutes of moderate or 75–150 minutes of vigorous physical activity per week.
While past research has already shown that exercise improves heart and mental health, this new study suggests it may also directly influence biological changes in the brain linked to Alzheimer’s.
The study followed 337 middle-aged participants in Catalonia who were part of the ALFA+ cohort, which includes people with a family history of Alzheimer’s disease. Over a four-year period, the researchers used questionnaires to measure changes in the participants’ physical activity levels. They also used brain scans to assess the structure and function of the brain.
Participants were grouped into three categories:
- Adherent: Those who met WHO’s recommended activity levels
- Non-adherent: Those who did less than the recommended amount
- Sedentary: Those who did no physical activity at all
One of the key findings was that people who increased their physical activity during the study had lower levels of beta-amyloid—a harmful protein that builds up in the brain and interferes with memory and communication between brain cells. Beta-amyloid buildup is considered one of the earliest signs of Alzheimer’s disease.
Even more encouraging, the benefit appeared to be dose-dependent: the more physical activity a person added to their routine, the greater the reduction in amyloid buildup.
Participants who were physically active—whether or not they met the full WHO recommendations—also had thicker brain cortexes in areas associated with memory and Alzheimer’s. Thinning of these brain areas is one of the earliest signs of neurodegeneration. This suggests that any amount of physical activity—even if it’s less than the official guidelines—can help maintain brain structure.
“Even those who didn’t reach the recommended activity levels still had better brain health than people who remained sedentary,” said Müge Akıncı, the study’s first author. “This shows that every bit of movement helps.”
The researchers emphasize that the key factor is increasing activity over time, not necessarily reaching a specific target immediately. People who gradually became more active saw benefits, regardless of where they started.
“These findings support the idea that middle age is a critical window for preventing Alzheimer’s,” said Dr. Eider Arenaza-Urquijo, lead investigator of the study. “Encouraging more physical activity during these years should be a top public health priority.”
The good news is that it’s never too late to start. Whether it’s walking more, dancing, biking, gardening, or joining a fitness class, adding movement to your daily routine—even in small amounts—can make a difference. And while there’s still no cure for Alzheimer’s, these results show that your lifestyle choices today can help protect your brain tomorrow.
In short, moving more in midlife isn’t just good for your heart and body—it may also help keep your brain sharp and resilient as you age.
If you care about brain health, please read studies about vitamin D deficiency linked to Alzheimer’s and vascular dementia, and extra-virgin olive oil could boost brain function.
For more information about brain health, please see recent studies about antioxidants that could help reduce dementia risk, and strawberries could help prevent Alzheimer’s disease
The research findings can be found in Alzheimer’s & Dementia.
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