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“Women are born with pain built in,” Belinda says in Season 2 of English actress Phoebe Waller-Bridge's BBC show “Fleabag.” “It's our physical destiny. Period pains, sore boobs, childbirth, you know.”
“We have pain on a cycle for years and years and years,” Belinda says. “And then, just when you feel you are making peace with it all, what happens? The menopause comes.”
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Just like pain, body hair and bra shopping, menopause is a rite of passage for female-assigned people — defined as the “permanent cessation of ovulation” in mammals by a 2023 paper from the German Cancer Research Center. It’s the last rung on the ladder, marking the ascension to the final boss level of matriarchy. At least, it should be.
Humans, it seems, are the last to figure that out. Our medical system still turns a blind eye to half of the world’s population. Including women in clinical research wasn’t enshrined in law until the NIH Revitalization Act in 1993. Yet even now, so-called “standardized” guidelines from car crash dummies to treatments for cardiovascular risk factors are based on data from men — even though cardiovascular disease is the number one cause of death in women.
Gender biases also show up in the less-than-rigorous testing for heart disease in women compared to men, gaps in knowledge of the different symptoms of heart attacks in women and, ultimately, the fact that women are more likely to die from these cardiac events than men.
These unequitable healthcare problems are only exacerbated when women reach menopause, which drastically increases risks for heart disease, hypertension, osteoporosis and possibly Alzheimer’s, autoimmune and inflammatory diseases. What else might we be missing?
“When we look at age-related diseases, over 75 percent of them are likely influenced by menopause in one way or another,” Dr. Fabrisia Ambrosio, associate professor of Physical Medicine and Rehabilitation at the Spaulding Rehabilitation Center, told Jennifer Walsh for Harvard Medical School. “But the great majority of preclinical biology research studies in aging fail to consider menopause in their experimental setup.”
Why does research on aging turn a blind eye to the effects of menopause? Well, besides the misogyny systemic to medicine and research, researchers haven’t had reliable animal models of menopause to extrapolate from.
In the animal kingdom, mammals rarely experience menopause. Instead, the vast majority of mammals die off relatively soon after they stop reproducing.
So far, researchers have observed menopause in humans, five species of toothed whales — orcas, false killer whales, belugas, narwhals and short-finned pilot whales — and, recently discovered, one population of chimpanzees. Menopause occurs so rarely, in fact, that there is no consensus about its evolutionary purpose. Why did female Homo sapiens evolve to live so much of their lives after reproductive age if natural selection is driven by “survival of the fittest,” and fitness measures reproductive success? What is the evolutionary advantage?
The common theory is called the “grandmother hypothesis,” first postulated by ecologist George C. Williams in 1957. The hypothesis goes that female mammals continue living long after they’re unable to reproduce because this frees them to gather resources and care for and ensure the survival of their grandchildren and, thus, their own genes — akin to the social structure of eusocial species like ants and bees. Studies of these whale species have observed gathering, sharing and child-rearing behaviors, which lends this hypothesis some credibility.
Not all of these mammals step into the “helpful grandmother” role, however. Of those that undergo menopause, humans are most closely related to chimpanzees, and it’s these apes who fall out of line. In a landmark 2023 paper, researchers found a population of chimps in Uganda who undergo the same hormonal changes as menopausal women but don’t partake in their assumed share of childcare, providing evidence to reject the grandmother hypothesis.
There might be something else going on here.
One problem is that chimps live very different lives than both us and whales, and I don’t just mean in trees. Chimpanzees of both sexes mate promiscuously and, as adults, males stay put while females leave for new communities. This means mothers care for their own offspring, but grandmothers probably don’t know who their grandchildren are. Even so, another researcher has observed one elder, female chimp Nambi in Budongo taking up the matriarchal helm on multiple occasions, seemingly leading and deciding for the group.
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“I was told it was horrendous,” Fleabag said in response. “It is horrendous, but then it's magnificent,” Belinda said back, with a smirk.
A greater quantity and depth of research is needed to discover the evolutionary purpose of menopause, which could vary between mammals, but the more we know about animals that are genetically similar, like chimpanzees, and behaviorally similar, like whales, to humans, the better.
Menopause is a complex and important process with a plethora of health effects, and, as life expectancy continues to rise globally, more people on earth will spend more of their lives post-menopause. So, the better we understand the process in model animal species, the better research we can conduct and the better knowledge we have of menopause in all mammals, the easier it will be to bridge those gaps in women’s, particularly aging, healthcare.
To ignore this need is to allow these gaps to turn into gulfs and our powerful, knowledgeable matriarchs to fall in.
Odessa Lyon (she/her) is a senior studying biology and English, pursuing a minor in European studies.
