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Healthy ageing in the Nun Study: definition and neuropathologic correlates
Suzanne L Tyas1, David A Snowdon, Mark F Desrosiers
1Department of Health Studies and Gerontology, University of Waterloo, Waterloo, Ontario, Canada. styas@uwaterloo.ca
Age and Ageing
|October 2, 2007
Summary
Defining healthy ageing is crucial for longevity. This study found that excellent healthy ageing significantly increases lifespan and reduces the risk of neuropathology, including Alzheimer's and stroke.
Area of Science:
- Gerontology
- Neurology
- Public Health
Background:
- The concept of healthy ageing lacks a universally accepted definition and established biological underpinnings.
- Interest in healthy ageing is high, necessitating a clear definition and understanding of its biological basis.
Purpose of the Study:
- To establish a definition for healthy ageing.
- To examine the relationship between this definition, longevity, and neuropathology.
Main Methods:
- Utilized data from the Nun Study (1991-1998), a longitudinal aging study of participants aged 75+.
- Defined three levels of healthy ageing (excellent, very good, good) using cognitive, physical, and self-rated function measures.
- Conducted mortality analyses on 636 participants and neuropathologic analyses on 221 autopsied participants.
Main Results:
- Only 11% of participants with excellent healthy ageing died, compared to 60% in the remaining group.
- Higher levels of healthy ageing were significantly associated with increased longevity.
- Risk of not achieving healthy ageing increased significantly with brain infarcts and Alzheimer's neuropathology, especially when both were present.
Conclusions:
- The developed definition of healthy ageing demonstrates biological validity through its strong association with mortality and longevity.
- Preventing Alzheimer's disease and stroke neuropathology is vital for maintaining healthy ageing.
- The co-occurrence of Alzheimer's and stroke pathologies substantially diminishes the likelihood of healthy ageing.
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