Reaping the hormonal rewards: investigating the role of sex hormones and cognitive performance in healthy older adults

Background Sex differences in cognitive performance have been extensively documented in scientific research, and these disparities continue to be observed in later stages of life. Gaining a comprehensive understanding of the underlying factors contributing to cognition in general and sex differences in specific is imperative to promote healthy cognitive ageing. Among these factors, sex hormones, specifically oestrogen and testosterone, have been implicated in cognitive performance variations. Nevertheless, there is a relative scarcity of studies investigating the relationship between sex hormones and cognitive performance in older adults. Hence, the current study aimed to investigate sex differences in cognitive performance and elucidate the association between sex hormones and these performance discrepancies. Methods Using confirmatory factor analysis in a sample of 121 older adults (aged ≥ 80 years), cognitive performance measures were divided into two cognitive components: executive functioning and memory. Subsequently, two mediation analyses were conducted. The first analysis aimed to determine the direct effects of sex and sex hormones (oestrogen and testosterone) on executive functioning and memory. The second analysis incorporated an oestrogen-by-sex interaction further to investigate the effects of oestrogen on cognitive performance. Results The results revealed that females outperformed males in executive functioning and memory, while oestrogen directly impacted performance. Furthermore, oestrogen exhibited a stronger association with executive functioning in females than in males. These findings indicate the possibility that early life or lifelong brain shaping influenced by sex hormones leads to the existence and persistence of sex differences in cognitive performance, with oestrogen playing a significant role in developing and maintaining female cognitive performance. Conclusion Overall, these findings have implications for basic research and clinical and cognitive ageing research development to promote cognitive health. Understanding the differences in cognitive abilities and the influence of sex-specific hormones between males and females can inform the research design and interventions to support healthy cognitive ageing.