The #1 Habit to Help Prevent Dementia, According to a New Study

Alzheimer’s disease is the most common condition that causes problems with memory and thinking skills, which is to say that it causes dementia. Alzheimer’s is sometimes caused when certain proteins, called beta-amyloid and tau, build up in the brain, leading to inflammation, brain cell damage and a decline in mental abilities.

While new treatments that target these proteins offer hope, Alzheimer’s disease is complex and requires a variety of approaches to slow or prevent its effects. One approach that has shown promise is physical activity, such as exercising. Evidence suggests that physical activity may protect the brain by improving how it adapts, reducing inflammation and improving blood flow—even if you only exercise a bit each day. Some studies in animals even show that exercise can lower the harmful proteins in the brain, though the results in humans are less clear. This highlights the need for more research to fully understand how exercise might influence these changes in the brain. 

To bridge this knowledge gap, researchers explored how physical activity and certain blood markers, known as plasma biomarkers, relate to memory and thinking abilities. These results were published today in JAMA Network Open.

How Was This Study Conducted?

This study examined mild cognitive impairment and Alzheimer’s disease using advanced methods across 25 centers in South Korea. Participants were carefully selected, with more than 1,100 individuals completing assessments like memory tests, blood analysis and brain scans. The study followed strict ethical guidelines and excluded anyone with conditions that could interfere with the results. Physical activity was measured via self-reports or caregiver input, and blood samples were analyzed for specific biomarkers linked to brain health. 

Researchers accounted for variables like age, sex and health conditions, with additional adjustments to account for amyloid-beta, a known factor affecting biomarkers and cognition. Statistical analysis was conducted using specialized software.

What Did the Study Find?

This study looked at how being physically active relates to brain health, specific proteins in the blood and thinking abilities. Researchers found three main things. First, people who were more physically active had lower levels of two harmful brain proteins (NfL and ptau217), which are linked to Alzheimer’s, and they performed better on memory and thinking tests. Second, these benefits were especially noticeable in older people and those already showing some signs of cognitive problems. Third, physical activity may directly improve brain health and thinking or may work indirectly by slowing down Alzheimer’s-related changes in the brain.

While the study suggests that staying active might help protect against brain aging and diseases like Alzheimer’s, scientists need more research to fully understand how physical activity influences the brain over time.

This study has many strengths. It included a large group of more than 1,000 participants from multiple centers, which helps make the results more applicable to a wider range of people and reduces the chances of bias that can happen in studies conducted at a single location. The study also used plasma biomarkers as a way to measure outcomes, which are expected to be useful in future treatments for physical activity interventions. 

However, there are some limitations to note. Since the study was cross-sectional, it shows associations but cannot prove cause-and-effect relationships. The mediation analyses were based on a hypothesis but are limited in this type of study and need further confirmation in future research over time. 

Additionally, the study relied on self-reported questionnaires, which can have errors if participants forget details or misreport their activity levels. For participants with cognitive impairment, data provided by caregivers may also vary depending on their knowledge of the participant’s routines and their ability to recall accurately. Lastly, this study was carried out in South Korea, so the results may not apply to other populations with different cultural or ethnic backgrounds. More research in diverse groups is necessary to confirm how broadly these findings can be applied.

How Does This Apply to Real Life?

This recent study suggests that incorporating physical activity may play a role in reducing the risk of Alzheimer’s disease, particularly among a specific population. As such, it may be worthwhile to start including physical activity in your lifestyle if you are focused on reducing your Alzheimer’s disease risk. However, it is important to consult with a health care provider before making major lifestyle changes to ensure that any new activity aligns with your health needs and abilities.

The good news is that physical activity doesn’t have to be strenuous to make a difference. Even small steps, like a daily walk or light stretching, can have a meaningful impact over time.

Other ways to incorporate physical activity into your routine include swimming, dancing, gardening or practicing yoga. Additionally, you can try incorporating more movement into your daily tasks, such as taking the stairs instead of the elevator, parking farther away to encourage walking or even doing household chores with more vigor. Small, consistent efforts can add up to significant benefits over time.

It’s essential to remember that there’s no single solution to preventing Alzheimer’s, but adding regular movement to your life is a proactive step that can support overall well-being. The key is to find activities you enjoy and make them a sustainable part of your daily routine.

The Bottom Line

Overall, the connection between physical activity and brain health offers a hopeful path forward in addressing Alzheimer’s disease. While it’s clear that staying active may help reduce certain harmful brain proteins and improve memory and thinking abilities, more research is needed to better understand these effects and how they vary across different populations. This study highlights an important piece of the puzzle, reinforcing the idea that lifestyle changes, such as regular exercise, can play a role in supporting brain health alongside other medical and therapeutic interventions.

Adopting physical activity doesn’t have to feel overwhelming or unattainable. Simple, consistent actions—like daily walks, engaging in hobbies or participating in community fitness classes—can create measurable benefits over time. What’s most important is finding activities that you genuinely enjoy, as these will be much easier to sustain in the long term. Alzheimer’s disease is undoubtedly complex, but by taking steps toward a more active lifestyle, you contribute to not just your physical health but also your mental and emotional well-being. The journey toward better brain health is one step at a time, and every effort counts.