Multilingualism and Dementia Risk: Longitudinal Analysis of the Nun Study.

BACKGROUND: Multilingualism is associated with enhanced executive function and may thus prevent cognitive decline and reduce the risk of dementia. OBJECTIVE: To determine whether multilingualism is associated with delayed onset or reduced risk of dementia. METHODS: Dementia was diagnosed in the Nun Study, a longitudinal study of religious sisters aged 75+ years. Multilingualism was self-reported. Dementia likelihood was determined in 325 participants using discrete-time survival analysis; sensitivity analyses (n = 106) incorporated additional linguistic measures (idea density and grammatical complexity). RESULTS: Multilingualism did not delay the onset of dementia. However, participants speaking four or more languages (but not two or three) were significantly less likely to develop dementia than monolinguals (OR = 0.13; 95% CI = 0.01, 0.65, adjusted for age, apolipoprotein E, and transition period). This significant protective effect of speaking four or more languages weakened (OR = 0.53; 95% CI = 0.06, 4.91) in the presence of idea density in models adjusted for education and apolipoprotein E. CONCLUSION: Linguistic ability broadly was a significant predictor of dementia, although it was written linguistic ability (specifically idea density) rather than multilingualism that was the strongest predictor. The impact of language on dementia may extend beyond number of languages spoken to encompass other indicators of linguistic ability. Further research to identify the characteristics of multilingualism most salient for risk of dementia could clarify the value, target audience, and design of interventions to promote multilingualism and other linguistic training as a strategy to reduce the risk of dementia and its individual and societal impacts.

Community Social Characteristics and Health at Older Ages: Evidence From 156 Religious Communities.

Objectives: Previous studies have found that individuals' health is associated with the social characteristics of their communities. However, interpreting the causality of the relationships is difficult due to a number of potential confounders on both the individual- and community-levels as well as potential selection effects. In the current article, we analyze data on health and community characteristics from Catholic order members aged 50+ living together in religious communities. We argue that the potential for confounders and selection effects is reduced in our sample. Method: We use multilevel group actor-partner interdependence models and cross-sectional questionnaire data (N = 1,041, k = 156 communities) to test whether individuals' self-rated health was associated with the level of social conflict and connectedness of their community separate from their own involvement in conflict and feelings of connectedness. Results: We find that living in communities with higher levels of conflict is associated with worse health, especially at older ages. We also find that (a) the relationship between health and own feelings of connectedness is stronger for men and (b) women report better health than men in more connected communities. Discussion: Our results offer further evidence that at least some social characteristics of the community have a causal impact on health.

A longitudinal study of the health status of a community of religious sisters: addressing the advantages, challenges, and limitations.

Longitudinal studies are recognized as contributing to understanding the complexity of aging and generating insights that cannot be gained using other research methods. However, conducting longitudinal studies is recognized as challenging, especially among older adults. The purpose of the current review is to describe how the authors addressed the limitations and challenges of longitudinal studies in a study of the health status of a community of religious sisters. Methods of this specific longitudinal study are presented to provide background to the discussion. Challenges, limitations, and advantages of the current longitudinal study are organized into three categories (i.e., sample, method, and data analysis) that have been addressed in the literature as contributing to the fidelity of longitudinal studies. The unique characteristics of the current study sample, particularly their access to health care, creates a comparison group for the study of older women in general.