Estrogen May Protects Cognition
Some sex hormones appear to be important for cognition. Studies in rats and monkeys have found an association between high blood levels of estrogen and performance on various cognitive tasks. A previous study of women with mild Alzheimer's disease showed that estrogen therapy improved verbal memory and attention; the effect disappeared when estrogen was discontinued. Several large studies have found an association between increased estrogen levels and diminished risk for developing Alzheimer's: One of these recently estimated that taking estrogen for more than a year reduces the risk by up to 5 percent annually.
Science 1997 May 2; 276:675-678