Supplementary Material for: Evidence on protective factors for dementia and cognitive impairment in older adults: an umbrella review

Introduction: Dementia represents a global public health challenge, and no conclusive evidence exists on how to prevent its onset or at least reduce the risk. This umbrella review aims to identify interventions or exposures that can reduce the incidence of dementia or cognitive impairment.
Methods: A search of meta-analyses and systematic reviews published from 2018 to 2025 (January) was conducted across four databases. Articles assessing associations between interventions or exposures to protective factors and incidence of dementia or cognitive decline in non-demented older adults were selected.
Results: Out of 6,324 articles, 177 underwent full-text screening, and 17 were included. They showed that psychosocial factors (social engagement, purpose in life, life satisfaction, and cognitive reserve) and influenza vaccination protect against dementia. Evidence on antihypertensives is promising, while evidence on low-dose aspirin is promising yet inconclusive. No clear results emerged for both single- and multi-domain lifestyle interventions.
Conclusions: These results offer new insight on potential targets for dementia prevention, a global public health priority. In particular, favorable psychosocial factors and influenza vaccination, undervalued in the scientific debate on dementia prevention, emerged as promising and feasible targets for preventive initiatives. Future research should focus on fine-tuning interventions to promote brain health, exploring their underlying mechanisms, and developing targeted and personalized strategies for specific population subgroups.

引言：痴呆症是全球公共卫生领域的一大挑战，目前尚无确凿证据表明如何预防其发病或至少降低患病风险。本伞状综述（umbrella review）旨在识别可降低痴呆症或认知障碍发生率的干预措施或暴露因素。
方法：在四个数据库中检索2018年至2025年1月发表的元分析（meta-analyses）和系统综述（systematic reviews）。纳入评估非痴呆老年人群中干预措施或保护性因素暴露与痴呆症或认知衰退发生率之间关联的文章。
结果：在6324篇文章中，177篇进行了全文筛选，最终纳入17篇。研究表明，心理社会因素（社交参与、生活目标、生活满意度及认知储备）和流感疫苗接种可预防痴呆症。降压药的相关证据具有前景，而低剂量阿司匹林的证据虽有前景但尚不确凿。单领域和多领域生活方式干预均未得出明确结果。
结论：这些结果为痴呆症预防这一全球公共卫生优先事项的潜在靶点提供了新见解。尤其值得注意的是，在痴呆症预防的科学讨论中被低估的有利心理社会因素和流感疫苗接种，已成为预防举措中具有前景且可行的靶点。未来研究应聚焦于优化促进脑健康的干预措施、探索其潜在机制，并为特定人群亚组制定靶向和个性化策略。