Boston—Estrogen prescribed to young female athletes who stop having their menstrual periods because of excessive exercise has an additional benefit: It also appears to improve their memory.

That’s according to a study presented recently at the Endocrine Society's 98th annual meeting in Boston.

Background information in the article cites the American College of Sports Medicine in reporting that amenorrhea occurs in up to 44% of women who exercise. Related estrogen deficiency also could be a cause of forgetfulness and poor concentration, according to the study, which referred to past research indicating a positive effect for estrogen replacement on mental processes such as memory in postmenopausal women and young girls with Turner syndrome, a genetic condition that can cause estrogen deficiency.

“This is the first study, we believe, to assess the impact of estrogen replacement on memory and other cognitive processes in young athletes who lose their periods due to excessive exercise,” explained lead investigator Charu Baskaran, MD, a pediatric endocrinologist at Massachusetts General Hospital for Children. “This information is important because these athletes are in their prime of neurocognitive development.”

The study, funded by the National Institutes of Health, examined the effect of estrogen replacement on mental processes, including memory, in 29 amenorrheic female athletes, ages 14 to 25 years, compared to 19 who received no estrogen replacement. Athletes in the study had stopped menstruating for longer than three months, or never started menses, because of too much aerobic physical activity, defined as more than 10 hours a week, according to the researchers.

For the investigation, study participants were randomly assigned to one of three treatment groups for 6 months: 1) oral estradiol and progesterone at a dose similar to that in many birth control pills (16 participants); 2) transdermal estradiol, the “estrogen patch,” at a physiological replacement dose with cyclic progesterone (13 athletes); or 3) no estrogen (19 subjects).

(Baskaran noted that participants who received estrogen therapy also received progesterone because taking estrogen alone raises risks of uterine cancer.)

Cognitive testing was administered before and after treatment, including assessment of verbal memory, specifically recall of spoken words using the California Verbal Learning Test, Second Edition.

Employing the Delis-Kaplan Executive Function System Color-Word Interference Test, participants also were evaluated on their ability to suppress a response as well as their cognitive flexibility allowing them to switch back and forth between different tasks—both considered crucial capabilities in everyday life.

Results indicate that athletes in the two estrogen treatment groups taken together had significantly better verbal memory and cognitive flexibility scores at the end of 6 months than their pretreatment scores, compared with those receiving no hormone treatment.

When the estrogen treated groups were evaluated versus no treatment, however, significantly greater improvement in certain cognitive tests was identified only in the group that received transdermal estrogen.

Baskaran said that transdermal estrogen administration is a more physiologic form of delivery than the oral preparation, adding that it is not metabolized in the liver. That is unlike oral estrogen, he said, which could affect other hormone levels that influence mental processes.

She called for studies in larger patient populations to confirm the results and to determine if cognition status differs between female athletes who stop menstruating and those who do not.

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