In the animal kingdom, only five species go through menopause, the stage at which the ovaries stop working. Four of them—killer whales, short-finned pilot whales, belugas, and narwhals—live underwater. The fifth species is, of course, humans. “This tells me as a scientist that menopause is not a biological imperative,” says Jennifer Garrison, a reproductive aging researcher at the Buck Institute in San Francisco. “It’s not necessary, so, from my perspective, we should get rid of it.”
Menopause remains a scientific puzzle. For instance, while the male reproductive system ages at the same rate as the rest of the body, the female one does not, with the ovaries, on average, aging at about two and a half times faster. “That means that when a woman is in her early thirties, when most of her body systems are functioning at peak performance, her ovaries are already showing overt signs of aging,” Garrison says. “The medical community actually considers them to be geriatric, which is a great term for someone who’s in their thirties.”
Of course, the male and female reproductive systems are very different. While men only start producing sperm at the onset of puberty, at a rate of a million sperm cells daily, a female fetus is born with approximately 6 to 7 million eggs in her ovaries—all the eggs she’s ever going to have. “What that means in practice is that even though I was born in the late 1970s, the egg that I came from was made in my mother’s womb in 1956.”
However, menopause not only has a profound effect on fertility, it also deeply affects women’s overall health. “After menopause, a woman has a fourfold increased risk of cardiovascular disease,” Garrison says. “Risks for diseases like osteoporosis, cognitive decline, arthritis, and autoimmune disease—they all go up.”
This accelerated reproductive aging means that, although women on average live some five years longer than men, they also tend to live a greater amount of time with poorer health. “The age at which a woman goes through menopause is linked to her overall lifespan,” Garrison says. “We have absolutely no idea what’s causing this correlation.”
Understanding the root causes, however, could have a profound effect on not just understanding female health, but also decoding the process of human aging. “Ovaries are the canary in the coal mine for aging.” Garrison says. “Understanding what is driving ovarian aging will give us clues about aging in the rest of the body.”
To reproductive aging researchers like Garrison, however, remaining obstacles have little to do with the inherent complexity of biology. For instance, in 2018, the National Institutes of Health (NIH), the largest biomedical research funding body in the US, only allocated 15 percent of its $27 billion budget to women’s health, and of that portion, less than 0.1 percent was devoted to female reproducing aging. “It’s basically a rounding error,” Garrison says.
Lack of research funding into reproductive aging is compounded by systematic biases that still affect biological and medical research. According to Garrison, only in 2016 did the NIH mandate that clinical studies include female animals as well as male. “The male body really has been biology’s baseline,” Garrison says. “That means that we have basically a century of preclinical data which was conducted and collected only in males.”
This already has serious consequences. According to data from the FDA Office of Women’s Health, 80 percent of drugs taken off the US market over safety concerns were pulled due to adverse effects in women. To rectify this, a few years ago Garrison cofounded the Global Consortium for Reproductive Longevity and Equality to support research on reproductive aging and science. “Our goal really is to just facilitate and accelerate taking those discoveries that happened in the lab and moving them into women’s hands faster,” Garrison says. “That means funding the science.”
This article appears in the July/August 2023 edition of WIRED UK magazine.
This article was originally published by WIRED UK
