Factors associated with brain ageing - a systematic review

Area of Science:

• Neuroscience
• Gerontology
• Biomarkers

Background:

• Brain age, a neuroimaging biomarker, predicts chronological age.
• Deviations in brain age indicate age-related brain changes (brain ageing).
• This review focuses on factors associated with brain ageing in adults.

Purpose of the Study:

• To systematically review and synthesize evidence on the association between lifestyle, health factors, diseases, and brain ageing in adult populations.
• To identify key factors contributing to accelerated or decelerated brain ageing.

Main Methods:

• Systematic review conducted following PRISMA guidelines.
• Searches of Embase and Medline databases, supplemented by examining reference lists of relevant reviews.
• Inclusion of studies on adult humans (18+ years) from clinical or general populations, considering all exposure types and study designs.

Main Results:

• 52 studies involving adults (mean age 21-78 years, ~37% female) were analyzed.
• Schizophrenia and Alzheimer's disease were most consistently associated with accelerated brain ageing.
• Evidence for other exposures (lifestyle, general health) is nascent and inconsistent, partly due to methodological heterogeneity.

Conclusions:

• Schizophrenia and Alzheimer's disease show robust associations with accelerated brain ageing.
• Evidence for other factors is limited and inconsistent, often due to cross-sectional designs and lack of replication.
• Future research should prioritize prospective studies to validate findings and explore other brain ageing correlates.