Women who participated in group activities had greater memory reserve, suggests a new study reported in the journal Neurology.¹

The study recruited 758 adults, aged 76 years (average) from the Washington Heights-Inwood Columbia Aging project (WHICAP). Sixty-two percent were women. Some of the participants had mild cognitive impairment, or dementia, while there were some who had no cognitive impairment. The aim of the study was to investigate the impact of physical activity on cognitive reserve for speed and memory in men and women. The Godin Leisure Time Exercise Questionnaire was used to extract information about their usual physical activity in a week, which was converted to metabolic equivalent of task (METS). The study subjects underwent MRI brain scans and thinking speed and memory tests. The sum of three self-reported yes/no questions about reading, attending group classes and playing games was used to calculate the cognitive activity (COGACT) score. Each activity was accorded one point and the maximum score was 3. The volumes of hippocampus, total grey matter, white matter hyperintensity and the composite cognitive scores for processing speed and memory were used to determine the cognitive reserve scores for speed and memory.

Results showed an association between greater processing speed reserve and higher METS among the women participants, but not in men. But physical activity was not associated with memory reserve in either men or women. The authors state, “Based on the effect sizes observed for physical activity (METS) and age, a two-fold increase in physical activity would be equivalent to an estimated 2.75 fewer years of processing speed aging in women”.

Higher cognitive activity scores were associated with greater memory reserve in women, but not in men. But cognitive activities were associated with greater speed reserve in both men and women. every extra cognitive activity amounted to “13 fewer years of processing speed aging (10 years among women, 17 years among men)”. However, the benefits of physical and mental activities on both speed and memory reserves was diminished among women who were carriers of the APOE4 gene.

A simplistic way to define cognitive reserve is the ability to maintain cognition even in the presence of underlying brain degeneration. A person with greater cognitive reserve can ward off cognitive impairment and future dementia. This study describes the gender differences in the relationship between self-reported physical and cognitive activities with cognitive reserve. While physical activity was associated with greater speed reserve in both men and women, cognitive activities were associated with greater memory reserve only in women. The authors speculate this difference could be attributed to the greater participation of women in group activities, which are cognitively more beneficial. Even though these findings show only an association and do not establish a cause-and-effect relationship, they will help the clinician to tailor the lifestyle recommendations to prevent onset of future dementia.

 Reference

1. Pa J, et al. Effects of sex, APOE4, and lifestyle activities on cognitive reserve in older adults. Neurology. 2022 Jul 20:10.1212/WNL.0000000000200675. doi: 10.1212/WNL.0000000000200675.