First published: 02/08/2024
Introduction
Sex hormones, particularly estrogens, play a vital role in various physiological processes beyond reproduction. The influence of estrogens on the central nervous system (CNS) and their subsequent impact on cognitive functions and psychological health, particularly during menopause, is a subject of significant interest.
The research by Esperanza Navarro-Pardo, Carol A. Holland, and Antonio Cano (2018) explores these connections, focusing on the effects of menopausal changes in estrogens on the brain, cognition, mood, and the potential role of hormone therapy (HT) in mitigating these effects.
Menopause and Cognitive Functions
Experimental and clinical evidence suggests that estrogens significantly influence brain biochemistry and morphology, affecting cognitive functions such as attention, memory, and executive function.
However, clinical studies have shown inconsistent results regarding the effects of reduced estrogen levels on cognitive performance in menopausal women. The research considers both direct and indirect effects of estrogen depletion on neural systems and cognition.
Direct Influence on Neural Systems
Estrogens exert neuro-protective actions by increasing neurotransmitter levels, enhancing neuronal growth, and maintaining neuroplasticity through the local production of estradiol in the brain. Estrogen receptors (ERs) are abundant in brain areas related to cognition, such as the hippocampus and prefrontal cortex.
Studies have shown that ovariectomy in pre-menopausal women and induced hypogonadism are associated with increased risk of memory problems and cognitive decline, supporting the role of estrogens in cognitive health.
Indirect Influence via Cardiovascular Health
Estrogens positively impact the vascular system, supporting cerebral blood perfusion. Menopausal symptoms like hot flushes may indicate vascular changes affecting memory. Cardiovascular health is crucial for cognitive function, with vascular factors implicated in many dementia cases. Thus, the decline in estrogens could indirectly affect cognition through its impact on cardiovascular health.
Clinical Studies on Cognitive Health
Cohort Studies
Longitudinal studies like the Kinmen Women-Health Investigation (KIWI) and the Penn Ovarian Aging Study (POAS) have examined cognitive performance in relation to menopausal stages and hormonal status. These studies found some evidence of cognitive decline, particularly in verbal fluency and memory recall, during peri-menopause and post-menopause. However, these effects are often modest and influenced by various factors, including age, education, and health.
Cross-Sectional Studies
The Study of Women's Health Across the Nation (SWAN) analysed cognitive function across different menopausal stages and hormonal levels. The findings suggest no direct effect of menopause or circulating estrogens on cognition once sociodemographic and health factors are accounted for.
Hormone Therapy and Cognition
The impact of hormone therapy (HT) on cognition has been widely studied, with mixed results. The Women's Health Initiative Memory Study (WHIMS) found that HT might increase the risk of dementia in older women. However, studies like the Kronos Early Estrogen Prevention Study (KEEPS) suggest that HT started near menopause might not harm cognitive function and may even offer some benefits. The evidence indicates that the timing, duration, and type of HT are crucial factors determining its impact on cognitive health.
Mood and Cognition
Mood disorders, including depression and anxiety, are more prevalent in women, especially during periods of hormonal fluctuations like menopause. Estrogens interact with serotonergic systems, potentially offering protection against mood changes. Depressive symptoms during peri-menopause can negatively affect cognitive function, highlighting the complex interplay between mood, cognition, and hormonal changes.
Cardiovascular Health and Cognitive Function
Cardiovascular health is closely linked to cognitive health. Estrogens support vascular health, and their decline during menopause increases cardiovascular risk, which can indirectly impact cognition. Studies suggest that maintaining cardiovascular health through HT and other interventions may help preserve cognitive function in menopausal women.
Conclusion
The research highlights the complex relationship between sex hormones, cognitive function, and psychological health in women. While menopause and the associated decline in estrogens can impact cognition and mood, the effects are influenced by various factors, including cardiovascular health and hormonal therapy.
HT does not provide a clear benefit for cognitive decline or dementia prevention in older women but may offer some protection when started early post-menopause. Further research is needed to clarify the optimal conditions for HT use and its long-term effects on cognitive health.
Overall, maintaining cardiovascular health and addressing mood disorders are crucial strategies for supporting healthy psychological aging in women during and after menopause.
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