Department of Psychological & Brain Sciences, Washington University in St. Louis, United States.
Department of Medical Social Sciences, Northwestern University Feinberg School of Medicine, United States.
Ageing Res Rev. 2024 Aug;99:102380. doi: 10.1016/j.arr.2024.102380. Epub 2024 Jun 14.
Wellbeing-defined broadly as experiencing one's life as enjoyable and fulfilling-has been associated with lower risk for Alzheimer's disease and related dementias. The mechanisms underlying this association are largely unknown. However, prior research and theory suggest that wellbeing impacts health behaviors and biological systems that are relevant to cognitive and brain health. Several of these factors have also been identified by the 2020 Lancet Commission on Dementia Prevention, Intervention, and Care as modifiable dementia risk factors. In the current review, we summarize and evaluate the evidence for associations between wellbeing and each of the 12 Lancet Commission risk factors. We found relatively consistent evidence for associations between higher wellbeing and lower levels of most of the risk factors: physical inactivity, social isolation, smoking, depression, hypertension, diabetes, hearing loss, traumatic brain injury, and air pollution. By contrast, we found evidence for only modest associations between wellbeing and education and mixed evidence for associations of wellbeing with alcohol use and body weight. Although most of the reviewed evidence was observational, longitudinal and experimental evidence suggests that many of the observed associations are likely bidirectional. These findings suggest that modifiable dementia risk factors may be mediators (i.e., intermediate steps in the causal chain) and/or confounders (i.e., variables that impact both wellbeing and dementia, and thus could induce a spurious association) of the association between wellbeing and dementia. We conclude by discussing next steps to test mediation hypotheses and to account for potential confounding in the relation between wellbeing and dementia.
幸福感是指人们觉得生活愉快且充实，而幸福感与阿尔茨海默病和相关痴呆症的风险降低有关。其背后的机制在很大程度上尚不清楚。然而，先前的研究和理论表明，幸福感会影响健康行为和与认知及大脑健康相关的生物系统。2020 年《柳叶刀》痴呆症预防、干预和护理委员会还确定了其中的一些因素，它们是可改变的痴呆症风险因素。在本综述中，我们总结和评估了幸福感与《柳叶刀》痴呆症预防、干预和护理委员会的 12 项风险因素之间关联的证据。我们发现，幸福感与大多数风险因素（身体活动不足、社交孤立、吸烟、抑郁、高血压、糖尿病、听力损失、创伤性脑损伤和空气污染）呈负相关，且证据相对一致。相比之下，我们发现幸福感与教育之间的关联仅略有证据，而幸福感与饮酒和体重之间的关联证据混杂。尽管大多数综述证据是观察性的，但纵向和实验证据表明，许多观察到的关联可能是双向的。这些发现表明，可改变的痴呆症风险因素可能是幸福感与痴呆症之间关联的中介因素（即因果关系链中的中间步骤）和/或混杂因素（即影响幸福感和痴呆症的变量，因此可能会导致虚假关联）。最后，我们讨论了下一步的研究，以检验中介假设，并考虑幸福感与痴呆症之间关系中的潜在混杂因素。
