MOUSE STUDY FINDS OVARIES AGE SIGNIFICANTLY BEFORE MENOPAUSE

Researchers at The Broad Institute of MIT and Harvard have identified evidence that ovarian tissue undergoes substantial age-related changes well before menopause occurs, according to a study published in Nature Aging. The study, led by cardiovascular researcher Hattie Chung, analysed ovarian samples from mice at various ages and reproductive stages. The findings suggest that reproductive decline may result not only from a diminishing egg supply but also from deterioration in the tissue environment surrounding the eggs.

The research examined 22 mouse ovaries and profiled 358 immature egg cells, 668 follicles, and 236 corpora lutea structures. As the mice aged, ovarian tissue showed signs of degeneration, with cells that normally work together to coordinate follicle development and ovulation becoming desynchronised. Immune cell activity in the ageing ovaries also shifted, with increased inflammatory signals and tissue disorganisation observed. Chung noted that humans typically retain approximately 1,000 eggs at the menopause transition, suggesting factors beyond egg depletion drive reproductive changes.

Because mice and humans share similar evolutionary biology, the findings may offer insights into human ovarian ageing, though mouse studies cannot definitively predict equivalent human outcomes. The ovaries perform critical endocrine functions beyond reproduction, producing hormones including oestrogen, progesterone, inhibin and testosterone that affect multiple body systems. The research adds to scientific understanding of why reproductive capacity declines with age, though further study would be required to confirm whether these patterns apply to human ovaries.