Early Menopause Linked to Lower Cognitive Function in Later Life

A study conducted by researchers from Tohoku University Graduate School of Medicine and Tokyo Metropolitan Institute of Medical Science has found that women who experience menopause before the age of 40 tend to have poorer cognitive outcomes compared to those who enter menopause after age 50. The study, published in Alzheimer's & Dementia: The Journal of the Alzheimer's Association, highlights a potential link between early menopause and increased risk of cognitive decline.

Dementia affects women disproportionately worldwide, leading the research team to investigate whether there are risk factors unique to women. Early menopause has been associated with a higher risk of depression, itself a known risk factor for dementia. However, there has been limited direct evidence regarding how the timing of menopause affects cognitive function and depressive symptoms as women age. 

The researchers analyzed data from the English Longitudinal Study of Ageing, categorizing menopause onset as before 40, between 40 and 49, and at 50 or older. The study included 4,726 women and 4,286 men, assessing cognitive abilities such as orientation, recall, and verbal fluency. The team examined the relationship between sex, age at menopause, and cognitive function two years later, adjusting for various modifiable dementia risk factors.

Lead author Miharu Nakanishi explained, "When looking for associations, we want to rule out as many other modifiable risk factors for dementia as possible." After adjusting for these factors, the study found that menopause before age 40 was significantly associated with lower scores in orientation and recall after two years, compared to menopause at age 50 or older. Notably, hormone replacement therapy did not show an association with cognitive outcomes.

The findings suggest that early menopause may identify a group of women at higher risk for cognitive decline, underscoring the need for further research into the mechanisms linking female hormone levels and cognitive health.