Cumulative estrogen exposure and prospective memory in older women

This study looked at cumulative lifetime estrogen exposure, as estimated with a mathematical index (Index of Cumulative Estrogen Exposure (ICEE)) that included variables (length of time on estrogen therapy, age at menarche and menopause, postmenopausal body mass index, time since menopause, nulliparity and duration of breastfeeding) known to influence estrogen levels across the life span, and performance on prospective and retrospective memory measures in a group of 50 postmenopausal women (mean age = 69.3 years) who, if they were current or former users of estrogen therapy, had started therapy within 5 years of menopause. The ICEE was found to be a significant predictor of performance on the Prospective Memory task (F(1) = 4.21, p = .046, ηp2=.084). No significant relationship was noted between the ICEE and performance on measures of retrospective memory. The results suggest that the level of cumulative lifetime exposure to estrogen a woman has influences her prospective memory performance later in life and that the influence of reproductive and biological markers of endogenous estrogen exposure are relevant factors to consider when studying the effect of estrogen therapy on cognitive functioning in postmenopausal women. In addition, the finding that performance on a measure of prospective memory, but not performance on measures of retrospective memory, was associated with the ICEE adds further support to the theory that the frontal cortex may be especially sensitive to estrogen.

► A mathematical index is developed to estimate cumulative estrogen exposure (ICEE). ► ICEE is positively correlated with prospective but not retrospective memory. ► Duration of breast-feeding is negatively correlated with prospective memory. ► Factors that influence levels of endogenous estrogen may influence cognition in later life.