Men produce reproductive hormones as they age. Why not women?
I consider myself a “paleo” physician, by which I mean one who bases her practice partly on principles derived from an understanding of human evolution and our healthiest possible relationship to the natural world. So friends and patients who know my paleo leanings are curious about the fact that I also recommend that women take hormone replacements during and after menopause. Of course, no cavewoman took replacement hormones, but to my mind that’s not really the point. Unlike so many medications people take today, smart cavewomen would likely have chosen to take hormone replacements if they had been available. Let me start with the basics to explain why.
All of us are descendants of ancestors who led successful lives. By success I don’t mean that they were necessarily smart or had the biggest cave, but rather it means that they were sufficiently strong to reproduce and that their progeny were also successful at reproduction—and continued to be successful over countless generations leading to us.
The primitive world offered many challenges to survival, but once early life challenges (infancy, contagious illness, injury, childbirth) were survived, our ancestors often lived to the age of 60–75 and raised surviving children. The ones who did not raise surviving children are no one’s ancestors.
Then and now, menopause ends reproductive ability long before women die from old age. Why? Because it was and is valuable to the woman and the tribe that she lose her fertility well before she becomes frail from aging. To conceive too late in life is to put many lives in jeopardy: her own, her child’s, and even those of her family or tribe. It’s no easy task to nurture a child. So women evolved to lose their ability to conceive a child at an age when they can reasonably expect enough healthy years to raise their last one.
Men, on the other hand, typically retain the ability to father a child until the end of life. The fertility disparity spans decades: Women typically lose their reproductive ability before age 50, while men keep theirs throughout life. The big difference now is that modern women get to choose whether or not to live for decades without the fertility hormones that are shut down by menopause.
The Ups and Downs of Hormone Replacement Therapy
The Downside: Biologically Equivalent Estrogen (estradiol) Taken Orally
• Increases risk of inflammation, blood clotting, and perhaps cardiovascular disease and strokes
The Upside: Biologically Equivalent Estrogen (estradiol) Applied on the Skin
• Acts as a neurotransmitter in the brain, enhancing cognition, sleep, and memory
• Promotes the health of gums and teeth, enabling a woman to keep her teeth and chew mastodon steaks right off the bone
• Seems neutral or protective against breast cancer, even for women with a history of estrogen-sensitive breast cancer
• Promotes healthy bones
• Seems neutral or protective in the realm of cardiovascular health
• Reduces the risk of colon cancer
The Downside: Synthetic Progesterone (medroxyprogesterone)
• Increases risk of breast cancer
The Upside: Biologically Identical Progesterone
• Acts in the brain, promoting sleep and calm mood
• Seems protective of the linings of blood vessels
• Protects against endometrial cancer (a risk of estradiol taken without progesterone)
The Downside: Biologically Identical Progesterone
• Can cause moodiness—from irritability to depression—in a minority of users
What we call hormones are proteins produced in one part of the body that act in a different part of the body. The pancreas makes the hormone insulin that balances sugars and fat in blood, muscles, and adipose tissue. The thyroid gland makes various thyroid hormones that work throughout the body, as do the adrenal gland’s cortisol and DHEA. In a healthy person, all these glands continue working throughout life. For some, however, aging entails lower thyroid or insulin production. You may be able to boost low hormone production with changes in diet and lifestyle, but eventually your doctor will typically replace any missing hormones to help your body function optimally.
The one notable exception is women’s reproductive hormones—estradiol and progesterone produced in the ovaries. Current thinking suggests replacing lost fertility hormones only during menopause, using as low a dose for as little time as possible to ease the unpleasant symptoms. I believe this derives from a misunderstanding of all the roles these reproductive hormones play. Let’s take a closer look.
Women of reproductive age cycle monthly through an intricate dance of two fluctuating, fertility-associated hormones: estrogen (as estradiol) and progesterone.
Women start this hormonal dance at puberty and suspend the cycling at menopause, so the whole purpose of these phases, from an evolutionary point of view, is to make pregnancy possible at an appropriate time in the woman’s life cycle.
After menopause, women continue to make other estrogens (estrone and estriol), but the production of estradiol falls to pre-pubertal levels, and without estradiol cycling, progesterone falls to zero.
Again, contrast women with men. Men make their fertility hormone, testosterone, starting at puberty, and keep on pumping it out for the rest of their lives, as long as they maintain good physical health. Frailty and malnutrition reduce testosterone production, and lack of testosterone itself causes frailty. So doctors are generally quick to replace testosterone in men.
Yellow Bird by Anne Siems
It’s no easy task to nurture a child. So women evolved to lose their ability to conceive a child at an age when they can reasonably expect enough healthy years to raise their last one.
You Don’t Know What You’ve Got Till It’s Gone
Over the last 60 years, reproductive hormone replacement for women has cycled in and out of favor. The most spectacular fall from grace occurred in 2002, when the Women’s Health International (WHI) study was prematurely terminated due to an uptick in the cases of breast cancer in the women receiving dual hormone therapy. It is important at this point to get specific. The WHI study was funded by pharmaceutical companies and used patentable medicines: “conjugated equine [yes, horse] estrogens (CEE)” instead of estradiol, and “medroxyprogesterone” instead of progesterone.
Research completed retrospectively on those same WHI women, as well as other research since that time, has uncovered a larger story. It turns out that the fertility hormones, similar to so many other hormones, perform many functions throughout the body. Like testosterone, women’s fertility hormones serve a variety of useful functions that have nothing to do with fertility (see box), but those healthy functions were traded away by evolution to prevent the calamity of an elderly woman’s getting pregnant.
So why the uptick in cancer from hormone replacement? Well, the effects of these replacement hormones vary, depending on whether they truly match the hormones that our bodies make. A patentable hormone—by definition—doesn’t match exactly, so the uptick in cancer rates was not the result of a fundamental flaw in hormone replacement therapy but the result of a pervasive problem within the pharmaceutical industry: the primacy of making a profit. When it comes to health research, greed is a powerful carcinogen.
The uptick in cancer rates was not the result of a fundamental flaw in hormone replacement therapy but the result of a pervasive problem within the pharmaceutical industry: the primacy of making a profit.
Today’s Elder Tribeswomen
I happen to be quite healthy for my age (almost 70). I’m still working and I’m still a competitive athlete—silver and bronze medals in my last rowing competition. It would not be good, however, for me or for my “tribe” if I were still able to get pregnant. What does serve me—and my tribe—is for me to stay as healthy as possible for as long as possible.
At our advancing age, my peers and I can continue to serve as grandmothers, hunter-gatherers, and even visionaries. We do so best if we avoid dementia, heart disease and strokes, loss of our teeth, and cancer of the breast or colon. So my plan is to keep exercising (outside with my team when possible), gnawing on bones, and refilling my prescriptions for bio-identical hormone therapy. Good for me, good for
Estrogen for a Better Bite
The ability to chew vigorously is both complex and interesting—and a key measure of overall health. To be able to chew vigorously, a woman must have strong teeth and healthy gums. Teeth respond to the same factors that bones do: Healthy bones and teeth depend on adequate sunlight or vitamin D, good gut health for vitamin K2, and exercise. To exercise your bones, walk and lift heavy things; to exercise your teeth, chew carrots and gnaw meat off the bone. For gum health, you need CoQ10 (highest in the meat from an animal’s heart) and good circulation. Estrogen helps all of this! And the benefit of healthy teeth is retaining the ability to chew vigorously, which is associated with better nutrition and even improved brain health.
Estrogen and Aging Men
Ironically, many of my male patients have estrogen (estradiol) levels that are higher than those in women of the same age who do not take hormone replacement. The reason: While both sexes have some of both male and female hormones, men get significant elevations of estrogen when they accumulate belly fat—fat that can make them look almost pregnant. An enzyme called aromatase, present in abdominal fat, is capable of transforming testosterone directly into estradiol! Great for bone strength for those men, but in truth, just a dab of estrogen is all they really need.