Photo Source: Yan Krukau
According to a recent study by Johns Hopkins Bloomberg School of Public Health, engaging in just five minutes of light exercise daily could significantly reduce the risk of dementia.
The study, which followed 90,000 adults in the UK, shows that even minimal physical activity has powerful effects on cognitive health. The findings were recently published in The Journal of the American Medical Directors Association.
Exercise and Dementia Risk
The study revealed a strong correlation between physical activity and reduced dementia risk.
Researchers found that individuals who engaged in just 35 minutes of moderate to vigorous physical activity (MVPA) per week—which breaks down to about five minutes per day—had a 41% lower risk of developing dementia compared to those who were inactive.
More exercise led to even greater benefits:
- 35-69.9 minutes/week → 60% lower risk
- 70-139.9 minutes/week → 63% lower risk
- 140+ minutes/week → 69% lower risk
Lead researcher Dr. Amal Wanigatunga highlighted the importance of small amounts of exercise, stating, “Our findings suggest that increasing physical activity, even as little as five minutes per day, can reduce dementia risk in older adults.”
The research further indicated that each additional 30 minutes of MVPA per week led to a 4% reduction in dementia risk, with the starkest difference seen between those who did no physical activity and those who engaged in even modest movement.
Why Exercise Helps
Though the study was observational and does not establish causation, experts suggest several possible explanations for the connection between physical activity and reduced dementia risk.
Dr. Marc Siegel, clinical professor of medicine at NYU Langone Health, highlighted that “There are many mechanisms that could explain this effect—primarily increased blood flow to the brain, as well as improved disposal of metabolic waste and decreased inflammation.”
Inflammation is known to play a major role in neurodegenerative diseases like Alzheimer’s, and Dr. Siegel added that increased activity “is likely associated with healthier lifestyle decisions that also decrease the advent of neuroinflammation, dysregulation, and plaque formation that characterise dementia, especially Alzheimer’s.”
Exercise is often associated with other health benefits, such as:
- Better sleep quality
- Healthier diet choices
- Higher levels of social engagement and mental stimulation
Study Limitations
While the study provides compelling evidence that minimal physical activity could reduce dementia risk, experts caution against drawing definitive conclusions. “This is not proof, just an association,” Dr. Siegel emphasised. “But it is very useful for the group that gets discouraged, thinking, ‘I can’t do a lot of exercise because of illness or disability, so why do any?’ This study suggests that even small amounts are helpful.”
Researchers accounted for potential biases by excluding dementia diagnoses made within the first two years of the study, ensuring more accurate results. The association between increased activity and reduced dementia risk remained significant even with this adjustment.
Dementia Prevention and Practical Implications
Dementia, especially Alzheimer’s, affects millions globally, making prevention a critical area of study. While public health guidelines typically recommend 150 minutes of moderate exercise per week, this new study suggests that even lower levels of physical activity can lead to significant benefits.
Dr. Wanigatunga highlighted that these findings are particularly encouraging for older adults who may struggle with intense workouts, saying, “This suggests that even frail or nearly frail older adults might be able to reduce their dementia risk through low-dose exercise.”