Menopause in MammalsFeb 27, 2014
We often say the human race is closely linked to chimpanzees, but menopause in women are actually similar to those of orcas’. The average age for menopause in American women is around 50, but how long does menopause last, and more importantly, how long does the average women live after her menopause? Dr. Kirtly Jones talks about the symptoms of menopause and how they’re different from symptoms of aging. She also discusses why she believes post-menopausal women are the civilizing force of society.
Dr. Kirtly Parker Jones: I'm too hot, I'm too cold, wait, I'm just right. That's Goldilocks doing menopause. Menopause happens at about 50, but aging happens too. What are symptoms due to menopause and what are symptoms due to aging? This is Dr. Kirtly Parker Jones from the Department of Obstetrics and Gynecology at University of Utah Health Care and this is menopause and this is The Scope.
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Dr. Kirtly Parker Jones: Why do women have a menopause? How is menopause different from aging? One, what do women and female orcas, killer whales, but I don't like that term very much, and pilot whales share, that almost no other mammals have? Well they share a long life after their baby making days are over, and they share language, and their kids take a really long time to grow up. Chimpanzees, with whom we share 98% of our genes die just a few years after their menopause. But humans and female orcas may live 45 years after their menopause.
Some famous evolutionary anthropologists think that the grandmother theory explains this. The grandmother theory suggests that having a grandmother helps the daughter be a better mother. More grandchildren survive. You need language to teach and humans have language, orcas have language, chimpanzees, not so much. So having a grand old lady around helps the tribe survive and run the PTA and the nonprofits and the family reunions. Postmenopausal women are the civilizing force of society.
Female orcas run the pack and teach their children and grandchildren how to hunt and their boys, like Italian boys, seem to take forever before they leave home, in fact, they never leave home. Orcas aren't sexually mature until their mid teens, later for males, and they aren't very good hunters until then as well. Sound familiar?
So, two, why isn't it so good for the tribe for women to die right after baby making is over? Well we talked about that. Grandmothers help the moms be better mothers. So why don't we make babies until we're 80? Men can. I think all of you who have had children can answer that one. Children who give birth very late in life are more likely to die before their adolescents can stand on their own emotional and financial feet. And pregnancy is really hard on the heart.
So, three, how is menopause different from aging? Well the ovary starts losing eggs before we are even born and we see peak fertility in the 20s. Fertility declines in the 30s and plummets in the 40s and is rare in the 50s. They average age for menopause in American women of all races is about 50, 51 for Caucasian women and the range is 40 to 61. The menopause is your last natural period. The ovary ages and the eggs aren't so fertile as they get older and periods aren't so predictable.
There is this time, before the menopause, when periods are less regular and some are skipped, this is the perimenopause and it has an average of about four years. Sorry ladies, I'm too hot, I'm too cold, oh, wait, I'm just right, that's kind of the perimenopause.
So looking at competitive athletes, it's rare to see them at the top of their game after 35. This is aging; the hearts, lungs, connective tissue, brain, bone density are at their peak in their 20s and start declining in the 30s. Women at 50 may complain about their memory, their wrinkles, their joints and their hot flashes, but only hot flashes is specifically linked to the decline in ovarian function. Of course, if you're having 25 hot flashes a day, it's hard to sleep and focus on things.
So what are the common menopause symptoms? Hot flashes and vaginal dryness, but not all women have them, 15% of Caucasian women will not experience hot flashes, Asian women have fewer, African American women have a few more, not everybody has them. But if you have a lot of hot flashes, how long will they last? Here's the bad news. An average of eight years. This is Dr. Kirtly Jones and thank you for joining us on The Scope.
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