Reproductive period and cognitive function in a representative sample of naturally postmenopausal women aged 60-64 years

Background: Greater lifetime estrogen exposure has been postulated to result in better cognition in later life, particularly in the area of verbal memory. In women, the highest levels of endogenous estrogen occur during their reproductive period, between menarche and menopause. Objective: To investigate the association between reproductive period and cognition. Methods: The sample consisted of 760 naturally postmenopausal women aged 60-64 years (mean age 62.5 ± 1.5 years) participating in the PATH Through Life Study who were randomly drawn from the population of Canberra, Australia. Participants were administered a verbal learning test (immediate recall and 1-minute delay), the Mini-Mental State Examination (MMSE), digit span backwards, the Symbol-Digit Modalities Test and simple and choice reaction time tests. Results: There were no significant associations detected between reproductive period and performance on any of the cognitive tests, either before or after controlling for potential confounding variables. Conclusions: Reproductive period, a surrogate measure of endogenous estrogen exposure, had no detectable effect on cognitive performance in this sample.