Examining a healthy lifestyle as a moderator of the relationship between psychological distress and cognitive decline among older adults in the NuAge study

Abstract

Introduction: The objective of this study was to examine whether a healthy lifestyle composite score of social engagement, physical activity, and Mediterranean diet adherence moderates the association between psychological distress and global cognitive decline among cognitively healthy older adults (67+ years of age at baseline).

Methods: A total of 1,272 cognitively intact older adults (Mage = 74.1 ± 4.1 years, 51.9% female) in the Quebec Longitudinal Study on Nutrition and Successful Aging (NuAge) completed a series of self-reported questionnaires to measure psychological distress and lifestyle behaviors, and the Modified Mini-Mental Examination (3MS) to assess cognitive performance at baseline and annually over 3 years.

Results: Controlling for sociodemographic and health-related characteristics, greater psychological distress was associated with steeper cognitive decline over time among males (B = -0.07, 95% CI: [-0.12, -0.02]), but not females (B = 0.008, 95% CI: [0.03, 0.04]). Although a healthy lifestyle composite score did not statistically significantly moderate the distress-cognition relationship (B = -0.005, 95% CI: [-0.02, 0.01]), there was an association between higher psychological distress and greater cognitive decline at low levels of social engagement (B = -0.05, 95% CI: [-0.09, -0.006]), but not at high levels of social engagement (B = 0.02, 95% CI: [-0.03, 0.07]).

Conclusion: This study suggests that the potentially harmful impact of stress on cognitive function may be malleable through specific healthy lifestyle behaviors and emphasizes the importance of taking a sex-based approach to cognitive aging research.

Plain Language Summary

Psychological stress is a risk factor for poor cognitive health during aging. However, some things might minimize the effects of stress on cognitive function. A healthy lifestyle is associated with better cognitive function and reduced feelings of stress. Therefore, the goal of the current study was to examine whether a healthy lifestyle including social engagement, physical activity, and Mediterranean diet minimizes the link between psychological distress and cognitive decline. The study was done over 3 years among 1,272 cognitively healthy older adults (average age: 74 years, 52% female) in the Quebec Longitudinal Study on Nutrition and Successful Aging (NuAge). Participants answered questions about psychological distress and lifestyle behaviours and completed the Modified Mini-Mental Examination once a year. The study results showed that greater psychological distress was associated with greater cognitive decline over time among males. In other words, for male participants, more stress led to more cognitive problems. This was not the case for female participants. There was also an association between higher psychological distress and greater cognitive decline at low levels of social engagement, but not at high levels of social engagement. This study suggests that the potentially harmful impact of stress on cognitive function may be modifiable through specific healthy lifestyle behaviours like social engagement. The study also emphasizes the importance of taking a sex-based approach to cognitive aging research.