New research finds that the menstrual cycle has no effect on cognitive function.
Researchers found that the hormonal changes that occur with menstruation have no impact on cognitive function - a finding that is likely to be welcome news for women of reproductive age.
Study leader Prof. Brigitte Leeners, of the University of Zurich in Switzerland, and colleagues recently reported their findings in the journal Frontiers in Behavioral Neuroscience.
The menstrual cycle involves the rise and fall of three key hormones: estrogen, progesterone, and testosterone. These hormones work to prepare the uterine lining for pregnancy. If pregnancy does not occur, the uterine lining is shed.
The varying hormone levels throughout the menstrual cycle have other effects, too, including changes in mood. But does the inevitable monthly cycle affect cognitive function? Many women assume so.
"As a specialist in reproductive medicine and a psychotherapist, I deal with many women who have the impression that the menstrual cycle influences their well-being and cognitive performance," says Prof. Leeners.
However, Prof. Leeners and team say that research on this widespread perception has produced conflicting results.
"Interpretation of observational studies on associations between prefrontal cognitive functioning and hormone levels across the female menstrual cycle is complicated due to small sample sizes and poor replicability," note the authors.
For their study, the researchers set out to gain a better understanding of whether or not menstruation affects cognitive functioning.
Hormonal changes and cognition
To reach their findings, the researchers enrolled 88 women of reproductive age who had regular menstrual cycles.
At four time points during one menstrual cycle, participants underwent tests that measured changes in three cognitive functions: attention, cognitive bias, and working memory. Subjects' hormone levels were also monitored.
The data revealed that changes in levels of estrogen, progesterone, and testosterone appeared to affect cognitive bias and attention. However, this finding could not be replicated.
On further analyzing 68 of the women during a second menstrual cycle, the researchers found no evidence that hormonal changes affected attention, cognitive bias, or working memory.
Based on these results, the researchers believe that menstruation is unlikely to affect a woman's brain power.
"Although there might be individual exceptions, women's cognitive performance is in general not disturbed by hormonal changes occurring with the menstrual cycle."
Prof. Brigitte Leeners
While these findings might put women's minds at ease, Prof. Leeners notes that further studies are needed to gain a clearer understanding of how the menstrual cycle affects cognition.
She adds that such studies would benefit from including larger groups of women, as well as women with hormone disorders.