A new study published in PLOS One reveals that spending more than eight hours a day sitting increases the risk of developing dementia by nearly a third. Researchers at York University in Canada analyzed data from 69 studies involving nearly 3 million adults over 35 to assess how physical activity, sitting time, and sleep affect brain health.
Key Findings
- Sedentary Behavior: People who sat for more than eight hours daily had a 27% higher risk of dementia compared to those who were less sedentary.
- Exercise Benefits: Regular physical activity reduced dementia risk by 25%, while poor sleep habits—either less than seven hours or more than eight hours per night—increased risk by 18% to 28%.
Protective Factors
The study emphasizes that breaking up prolonged sitting with short walks or movement can mitigate risks. Lead author Akinkunle Oye-Somefun noted that exercise and good sleep are crucial for long-term brain health. Phillip Hwang, an epidemiologist at Boston University, agreed, stating that even modest activity can have lasting benefits.
Global Impact
Dementia affects 55 million people worldwide, with costs projected to reach £1.6 trillion by 2030. In the UK, cases are expected to rise from 982,000 to 1.4 million by 2040. The study highlights the importance of lifestyle changes as a low-cost, accessible way to reduce dementia risk.
Methodology
The research synthesized data from studies spanning eight decades, with participants averaging 67 years old and residing in high-income countries. The findings suggest that simple lifestyle adjustments—such as increasing movement and improving sleep—can have a meaningful impact on cognitive health.