The Relation of Obesity to Performance in Verbal Abilities, Processing Speed, and Cognitive Flexibility in Old Age: The Role of Cognitive Reserve

Abstract

Aims: The present study set out to investigate the relation of obesity to performance in verbal abilities, processing speed, and cognitive flexibility and its interplay with key correlates of cognitive reserve in a large sample of older adults. Methods: A total of 2,812 older adults served as a sample for the present study. Psychometric tests on verbal abilities, processing speed, and cognitive flexibility were administered. In addition, individuals were interviewed on their weight and height (to calculate body mass index; BMI), educational attainment, occupation, and engaging in different activities throughout adulthood. Results: Obesity (BMI ≥30) was significantly associated with a lower performance in verbal abilities, processing speed, and cognitive flexibility. Moderation analyses showed that obesity was related to lower processing speed and cognitive flexibility only in individuals with low engagement in activities and low education. Hierarchical regression analyses showed that obesity was not related to any of the three investigated cognitive performance measures when cognitive reserve in early and midlife was taken into account. Conclusion: Present data suggest that cognitive reserve accumulated during the life course may reduce the detrimental influences of obesity on cognitive functioning in old age.

Cognitive Reserve and Social Capital Accrued in Early and Midlife Moderate the Relation of Psychological Stress to Cognitive Performance in Old Age

“…Specifically, the relations of psychological stress to cognitive performance were reduced in individuals with higher education, a higher cognitive level of the first profession practiced after education, a larger number of midlife leisure activities, a larger number of significant family members, and a larger number of close friends. This is in line with studies showing that cognitive reserve and social capital may offset the detrimental influences of physiological stress on cognitive functioning in old age [2, 12, 21, 36] and extends prior evidence suggesting that the relation of psychological stress to cognitive functioning is smaller in individuals with higher scores in a late-life proxy of cognitive reserve [37], with data based on a comprehensive set of key life course markers of cognitive reserve and social capital in a large sample of older adults in the present study.…”

“…Notably, in line with that, recent empirical evidence suggests that cognitive reserve (in terms of e.g. higher education, higher cognitive level of job, and greater engaging in leisure activities) may offset the detrimental influences of strong physiological stressors such as metabolic syndromes and chronic diseases (e.g., unfavorable blood fat level, obesity, and hypertension) on cognitive performance (e.g., memory and executive functioning) in old age [2, 12, 36]. Likewise, with respect to compensation of physiological stressors by social capital, Bennett et al [21] found in a sample of 89 older adults that social network size moderated the negative association between Alzheimer disease pathology and cognitive performance (semantic memory and working memory).…”

High-Density Lipoprotein Cholesterol Level Relates to Working Memory, Immediate and Delayed Cued Recall in Brazilian Older Adults: The Role of Cognitive Reserve

“…In individuals with healthy cognitive functioning, these mechanisms contribute to the adaptation of brain activity when the task difficulty level is increased and thereby enhance cognitive performance [4]. Empirically corroborating the predictions of the cognitive reserve concept, both correlational and causal evidence showed that longer education in early life, cognitively demanding occupation in midlife, and cognitive leisure activity in midlife and old age contribute to the buildup of cognitive reserve during the life course and are related to better cognitive functioning such as memory and executive functioning in old age [5,6,7,8,9,10,11,12,13,14,15,16,17]. …”

“…Notably, recent evidence suggests that cognitive reserve (in terms of higher education and greater engagement in cognitive leisure activity) may offset the detrimental influences of metabolic syndromes such as obesity on cognitive performance (e.g., executive functioning) in old age [12]. In terms of such compensation effects, the cognitive reserve concept postulates structural and functional mechanisms [4].…”

“…In individuals with healthy cognitive functioning, these mechanisms contribute to the adaptation of brain activity when the task difficulty level is increased and thereby enhance cognitive performance [4]. Thereby, structural and functional compensation effects of cognitive reserve may buffer the detrimental influences of metabolic syndrome-related cardiovascular and cerebrovascular diseases on cognitive performance [4,12]. …”