"This is the first study to specifically examine the effect of estrogen on reading ability," said principal investigator Sally Shaywitz, M.D., professor of pediatrics and in the Yale Child Study Center. "Most of the research examining the association between estrogen use and cognitive function has focused on global, more non-specific, mental status or memory as the principal outcome."
"The study also shows that estrogen may benefit younger postmenopausal women engaged in everyday activities, such as reading," Shaywitz added. "It should encourage physicians caring for postmenopausal women to inquire about and take seriously concerns about difficulties in reading and in memory."
The study was a randomized double blind placebo-controlled trial in a group of 60 postmenopausal women ages 32.8 to 64.9. Participants were evaluated for oral reading, verbal memory and other cognitive skills. They were treated for two periods of 21 days each: one period with estrogen and after waiting 14 days, another period with placebo.
Shaywitz obtained data on oral reading using the Gray Oral Reading Test and on verbal memory using the Wechsler Memory Scales and the Sentence Span Test. Mood was assessed with the Beck Depression Inventory and no significant difference was recorded between placebo- and estrogen-treated subjects. Vocabulary, attention and nonverbal memory were comparable in placebo and estrogen groups.
"In contrast to previous research examining estrogen and cognition, this study is hypothesis-driven, reflecting neurobiological, behavioral and brain imaging data," said Shaywitz. "The neurobiological data shows estrogen's beneficial effects on basic neural processes; the behavioral data indicates estrogen positively affects phonologic (sound-based) cognitive processes known to be central to reading; and the brain imaging data indicates estrogen produces brain activations in the inferior parietal lobule, a region sensitive to phonological demands and implicated in reading."
Shaywitz and her team found that estrogen exerts positive effects on oral reading and verbal memory in midlife postmenopausal women. The new findings also suggest estrogen not only affects brain regions comprising the neural system used for word identification, but that it also influences reading performance itself.
"This should encourage a new line of investigation seeking to better understand estrogen's actions on reading and memory," Shaywitz said. "These data are also important in clarifying those areas of cognition, such as vocabulary and spatial ability not sensitive to estrogen; they indicate estrogen is not simply a panacea for a range of cognitive difficulties, but has specific effects which can be explained through its actions on phonologic processes."
Other Yale authors on the study include Frederick Naftolin, M.D., Daniel Zelterman, Karen E. Marchione, John M. Holahan, Steven F. Palter, M.D., and Bennett A. Shaywitz, M.D.