Getting active in midlife may boost brain resilience to Alzheimer’s

By Admin

02 May, 2025

As we move through our 40s and 50s, staying physically active isn’t just good for our bodies—it may also be a crucial defense mechanism against Alzheimer’s disease (AD). A recent study published in the journal Alzheimer’s & Dementia suggests that midlife physical activity, especially when aligned with World Health Organization (WHO) recommendations, could play a vital role in slowing early Alzheimer’s-related changes in the brain.

Midlife: A Crucial Window for Brain Health

Alzheimer’s begins long before the first symptoms appear, often with silent changes in the brain such as amyloid-β (Aβ) plaque buildup and cortical thinning in vulnerable regions. These alterations can begin in midlife—especially in those with genetic or familial risk. This is why researchers are increasingly exploring modifiable lifestyle factors, like physical activity, that may protect the brain before symptoms arise.

The Study at a Glance

Researchers analyzed data from 337 middle-aged adults (aged 45–65) in Catalonia, most of whom had a family history of AD. Participants reported their physical activity levels twice over four years. Brain imaging data was collected at the second time point, including PET scans for Aβ and MRIs for cortical thickness.

Participants were grouped based on how their physical activity levels changed:

• Maintained sedentary
  
  

• Maintained non-adherence
  
  

• Became adherent
  
  

• Became non-adherent
  
  

• Maintained adherence
  
  

The WHO recommends at least 150 minutes of moderate-intensity activity or 75 minutes of vigorous activity per week. Adhering to these guidelines had a significant impact.

Key Findings

The study revealed several compelling findings:

• Lower Amyloid Burden: Those who became adherent to WHO activity guidelines showed a significant reduction in Aβ burden compared to those who became non-adherent or remained sedentary.
  
  

• Greater Cortical Thickness: Participants who stayed or became active—even below the recommended activity levels—had greater cortical thickness in AD-sensitive regions than those who remained sedentary.
  
  

• Dose-Response Relationship: More physical activity was linked to lower Aβ levels, reinforcing the idea that "more is better" when it comes to brain protection.
  
  

Even after adjusting for variables like age, sex, genetics (APOE-ε4 status), cardiovascular health, and mental health, these associations held strong.

What This Means for You

This research suggests that it's never too late to start moving. Increasing or maintaining physical activity in midlife may offer neuroprotective benefits, helping the brain resist Alzheimer’s-related changes. Even if you don’t meet the full WHO guidelines, being somewhat active is significantly better than being sedentary.

Limitations to Consider

While the findings are promising, the study had limitations. The use of self-reported activity, lack of ethnic diversity, and the measurement of brain changes only at follow-up mean causality can't be definitively proven. Also, other factors like sleep quality or neurogenesis were not examined.

Final Thoughts

Adopting a more active lifestyle in your 40s and 50s may do more than keep you fit—it could also strengthen your brain’s defenses against Alzheimer’s. Whether you’re taking up brisk walking, cycling, or even gardening, these activities could be a powerful step toward lifelong brain health.