Alzheimers Dementia: Integrating 8 countries, 10,000 big data: more exercise can reduce dementia risk

Dementia is one of the leading causes of disability and dependence in older adults, as it affects memory, thinking, behavior and the ability to perform daily activities
.
Currently, more than 50 million people worldwide suffer from dementia, and by 2050 the number is estimated to be close to 152 million

Physical activity is defined as any physical movement produced by skeletal muscles that requires energy expenditure
.
Physical inactivity, along with 11 other modifiable risk factors, accounts for 40% of dementia worldwide and, therefore, could theoretically prevent or delay, according to the Lancet Commission's 2020 report on dementia prevention

Understanding the dose-response relationship between physical activity and dementia is critical for both the design of intervention studies and the development of evidence-based guidelines for physical activity
.
Several previous studies have examined the potential dose-response relationship between later-life physical activity and dementia risk

The Coalition for Memory Cohort Study (COSMIC) has combined data from population-based longitudinal cohort studies to identify common risk and protective factors for dementia and cognitive decline
.
This consortium provides us with an opportunity to use a unified approach to calculating and classifying physical activity across multiple cohorts

Hereby, Ding Ding et al.
of Fudan University conducted a pooled analysis based on 10 cohorts of COSMIC to investigate the dose-response relationship between physical activity in later life and the risk of developing dementia

They found that with no physical activity as a reference, dementia risk decreased with increasing physical activity time up to 3.
1 to 6.

For physical activity, a similar pattern of dose-response curves was observed, with an inflection point of 9.
1 to 18.
0 metabolic equivalents (MET)-hour/week (HR 0.
92, 95% CI 0.
70 to 1.
22 for 0.
1 to 9.
0 MET-hour/week ; 9.
1 to 18.
0 MET-hours/week HR 0.
70, 95% CI 0.
53 to 0.
93)
.

The significance of this study is that it found that 3.
1 to 6.
0 hours of physical activity and 9.
1 to 18.
0/MET-hours of energy per week may reduce dementia risk
.