Edited by Eleonora Maria Vladimiro, Well.cy
For years, scientists believed that the ovaries became almost inactive after menopause, as they stopped releasing eggs and significantly reduced their hormone production. However, new scientific evidence is challenging this assumption, suggesting that the ovaries may continue to perform important biological functions long after a woman's reproductive years have ended.
Research suggests that postmenopausal ovaries do not simply become dormant. Instead, they undergo active molecular changes and may take on a new role involving the immune system, inflammation and possibly the ageing process.
Ovaries may remain active after menopause
Reproductive biologist Francesca Duncan of Northwestern University in the United States has spent years studying the changes that occur in the ovaries after a woman's reproductive years come to an end.
In a new study involving mice, Duncan's research team, working with scientists from other US research institutions, found that older ovaries continue to show significant biological activity.
The findings are consistent with a second study by Duncan involving 28 postmenopausal women. Although this research has not yet undergone peer review, it found that the proteins produced by ovarian tissue vary between age groups.
If the ovaries became completely inactive after menopause, scientists would not expect to find such differences in their activity.
What the study on mice revealed
Scientists examined ovaries from mice of different ages: two, 18 and 24 months. In mice, reproductive function comes to an end at around two years of age. This has some similarities to human menopause, although the hormonal changes are not exactly the same.
The researchers analysed ovarian tissue using advanced molecular techniques, including RNA sequencing. This method allows scientists to identify which genes are active inside cells and which proteins they produce.
As expected, reproductive activity declined with age. Older mice had fewer ovarian follicles, along with changes in tissue structure and collagen.
However, these changes did not mean that the ovaries had stopped functioning. Instead, they appeared to have taken on a different role.
From reproduction to immune function
The study's most interesting finding was that older ovaries showed increased activity in genes associated with the immune system.
Researchers also found higher numbers of cells such as:
- T lymphocytes, which help protect the body against infections and other threats.
- Macrophages, which remove dead or damaged cells.
- Multinucleated giant cells, which are associated with inflammatory processes.
According to the research team, ovaries may develop the characteristics of an immunologically active organ after a woman's reproductive years end.
In other words, while their main functions during a woman's reproductive years involve producing eggs and hormones, they may play a greater role in regulating inflammation and immune responses after menopause.
What the findings could mean for women's health
The discovery could offer new insights into how the female body ages. Menopause brings significant changes, as declining oestrogen levels affect several bodily systems, including bone health, the heart, metabolism and brain function.
If the ovaries continue to influence the immune system after menopause, future research could help scientists better understand the connection between hormonal changes, chronic inflammation and diseases that become more common with age.
More research is needed
Scientists caution that findings from animal studies cannot automatically be applied to humans. Although mice share several biological similarities with humans, further studies involving women are needed to confirm the exact role of postmenopausal ovaries.
Nevertheless, the findings challenge the long-held belief that ovaries become little more than an inactive remnant of a woman's reproductive system after menopause.
Instead, they may remain dynamic organs that continue to interact with the rest of the body and influence women's health, even many years after their final menstrual period.
The study was published in the journal Molecular Human Reproduction.
Source: ScienceAlert
