Nancy Sin

Physical activity (PA) has been linked to better cognitive performance, although less is known regarding the potential benefits of different intensities of PA on long-term cognition and if these benefits differ by age. Therefore, the present study examined age moderation in the associations of light, moderate, and vigorous intensity self-reported leisure-time PA with 9-year change in cognitive performance. On an exploratory basis, we examined inflammatory biomarkers interleukin (IL)-6, IL-8, and C reactive protein as mediators, and tested age as a moderator of this mediation. Data came from 2311 adults (aged 35-85 at baseline, 57% female) from the Midlife in the United States Study. At baseline and approximately 9 years later, physical activity was measured via questionnaire, and cognitive performance was assessed via telephone, tapping into episodic memory and executive function. In regression models, PA intensities were evaluated as predictors of later cognitive performance and age was examined as a moderator of these links. Analyses controlled for baseline cognition, depressive symptoms, and sociodemographics. When examined separately, moderate and vigorous (but not light) intensity PA each predicted better 9-year episodic memory, but only the association for moderate PA remained when controlling for all PA intensities. This association was not evident for executive functioning. Age did not moderate any these associations. In exploratory analyses (n = 906 participants who had provided blood samples), none of the inflammatory markers mediated the relationship between physical activity and later memory, and age did not moderate this relationship. These findings suggest that moderate leisure-time PA may be protective for forestalling age-related changes in episodic memory across the adult lifespan. Given that inflammatory markers did not mediate this relationship, future work should focus on delineating the underlying mechanisms.

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Objective: Abundant evidence has linked everyday discrimination with health risks. Since the COVID-19 pandemic has increased exposure to discrimination (e.g., based on age and race), it is important to understand the day-to-day implications of discrimination experiences with well-being. Furthermore, daily positive events were examined as a moderator due to their potential for mitigating the associations between everyday discrimination and well-being. Methods: From March to August 2020, 1,212 participants aged 18-91 in the U.S. and Canada (84% women, 75% White) completed surveys for seven consecutive evenings about everyday discrimination, positive events, physical health symptoms, and positive and negative affect. Data were analyzed using multilevel models and controlled for sociodemographic factors. Results: Everyday discrimination was reported on 9.3% of days when in-person or remote social interactions occurred. Within-persons, positive affect was lower and negative affect and physical symptoms were higher on days when discrimination occurred vs. on days without discrimination. Positive events mitigated the within-person association between everyday discrimination and same-day negative affect, but not for positive affect or physical symptoms. Age was the most frequently reported reason for perceived everyday discrimination. Age-based discrimination predicted poorer same-day affect (but not same-day physical symptoms), and these associations were not buffered by positive events.Conclusions: Everyday discrimination was related to lower daily positive affect and higher negative affect and physical symptoms during the COVID-19 pandemic. This study provides initial evidence that daily positive events partially offset the increased negative affect associated with same-day discrimination, although this effect did not extend to age-based discrimination.

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Greater perceived control is associated with better health and well-being outcomes, possibly through more adaptive stress processes. Yet little research has examined whether global perceived control, as well as its facets of personal mastery and perceived constraints, predict psychological and physiological stress reactivity. Thus, the goal of the present study was to evaluate the associations of perceived control and its facets with changes in subjective stress and cortisol in response to acute laboratory stressors. In addition, we considered the moderating roles of age and race. In a sample of 735 U.S. adults ages 25–75 (71% White, 18% Black, 11% Other/Unknown Races), participants completed a measure of perceived control at baseline and subsequently underwent two lab-based acute stress tasks. Subjective stress and salivary cortisol were collected pre- and post-stressors. Perceived control was related to smaller increases in subjective stress, but did not directly predict cortisol responses. Age and race interacted to moderate the associations between facets of perceived control and stress reactivity. Specifically, greater personal mastery predicted lower subjective stress responses in White older adults, and higher perceived constraints predicted greater cortisol reactivity among White younger adults, whereas no association was found among racial minorities. These findings suggest that, among Whites, older adults garner the stress protective benefits of mastery and are buffered against the link between constraints and cortisol stress reactivity. Future research on the role of perceived control in stress and health should distinguish between facets of control as well as consider the importance of age and racial differences.

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