Most people think of bones as scaffolding: rigid, inert structures that hold you upright and give your muscles something to attach to. A frame. A skeleton. The strong, silent type.
But that understanding is decades out of date.
Your bones are living, metabolically active organs. They’re master communicators that send hormones to your brain, muscles, pancreas, and even your reproductive organs. They regulate glucose metabolism, protect against cognitive decline, boost testosterone production in men, and influence everything from memory formation to insulin sensitivity.
In other words, your bones don’t just hold you up. They help you live longer and age well.
And women, especially, need to take care of them.
Bones Are Endocrine Organs: The Osteocalcin Revolution
For most of human history, we thought bones were metabolically inert. We knew they stored minerals like calcium and phosphorus, sure. But active participants in your body’s hormonal symphony? That idea is relatively new.
The breakthrough came with the discovery of osteocalcin, a hormone produced by osteoblasts (bone-building cells) that acts as a master regulator throughout the body.
Dr. Vonda Wright, an orthopedic surgeon and healthy aging expert, explains the significance:
“When your osteoblasts, the bone building cells in your bones release osteocalcin, it goes to your brain and has a neuroprotective effect by decreasing inflammation. It goes to your brain and causes the synthesis of neurons in the hippocampus. It goes to the pancreas and helps with insulin insensitivity. It goes to the muscle and helps the muscles scoop up glucose out of the blood. If you’re a man, osteocalcin can travel to the testes and that organ, the Leydig cells under stimulation of osteocalcin will produce testosterone.” [^1]
Let that sink in. Your bones are:
- Protecting your brain from oxidative damage
- Growing new neurons in the hippocampus (the memory center)
- Regulating blood sugar by improving insulin sensitivity
- Helping muscles absorb glucose from the bloodstream
- Boosting testosterone production in men
And that’s just one hormone. Bones also produce and respond to other signaling molecules, creating an intricate communication network with muscles, organs, and the brain.
The Bone-Brain Axis: Your Skeleton Talks to Your Mind
The connection between bone health and brain health is profound and bidirectional.
When you exercise, particularly with resistance training or weight-bearing activities, your bones experience mechanical stress. In response, they release osteocalcin and other hormones into the bloodstream. These molecules cross the blood-brain barrier and trigger neurogenesis: the growth of new neurons.
As Andrew Huberman, neuroscientist and professor at Stanford, explains:
“Your bones release hormones, in particular, something called osteocalcin… Osteocalcin is released from the bones during exercise, both in mice and in humans, travels to the brain so it can cross the blood-brain barrier, and there it can encourage the growth of neurons and their connections within the hippocampus, an area of the brain that’s vitally important for the encoding of new memories.” [^2]
Even more remarkable, people with low bone density show higher rates of cognitive dysfunction as they age. And those with osteoporosis have higher risks of cognitive decline and dementia. [^1]
This isn’t just correlation. There’s a clear biological mechanism at play: healthy bones produce hormones that protect and strengthen the brain.
Your skeleton isn’t just holding up your body. It’s holding up your mind.
Bones as Your Body’s Mineral Bank (And Why That Matters)
Beyond hormone production, bones serve as your body’s storage facility for critical minerals, particularly calcium and phosphorus.
Calcium isn’t just important for bone strength. It’s essential for:
- Muscle contraction (including your heart)
- Nerve signaling
- Pushing molecules across cell membranes
- Blood clotting
Your body maintains a delicate calcium balance. When blood calcium levels drop, your body sends signals to the bones: “We need calcium. Release some.” Osteoclasts (bone-breaking cells) then break down a small amount of bone tissue to release calcium into the bloodstream.
When you have enough calcium circulating, the process stops. The body is perfectly calibrated to maintain homeostasis. [^1]
But here’s the problem: if you’re chronically low on calcium intake (or vitamin D, which helps you absorb calcium), your body has to constantly pull from your bone reserves. Over time, this weakens your skeleton and increases fracture risk.
Worse, if you’re not building strong bones early in life or maintaining them through adulthood, you’re setting yourself up for serious problems later.
Women Face Unique (and Brutal) Bone Health Challenges
While everyone needs to care for their bones, women are at significantly higher risk for bone loss and fractures.
Here’s why:
1. Women Build Less Bone Mass Initially
Men, thanks to testosterone and XY genetics, build thicker, denser bones during their youth. Women’s bones are lighter and smaller to begin with. [^3]
Dr. Vonda Wright notes that peak bone mass occurs around age 28 in women and age 30 in men. After that, you plateau and then begin to decline. [^3]
If you don’t build strong bones during your youth, you’re starting from a weaker baseline.
2. Women Lose Bone Density Much Faster
Starting around age 40, women begin losing bone density at an accelerated rate due to declining estrogen levels. By menopause, women have lost approximately 20% of their bone density. [^3]
Men? They maintain bone density until their 70s. It’s a gradual slope for them. For women, it’s a cliff. [^3]
Why? Because estrogen is critical for bone health. It helps bones absorb calcium and signals osteoblasts to build new bone tissue. When estrogen plummets during menopause, bone loss accelerates dramatically.
3. Three Critical Windows for Women’s Bone Health
There are three periods in a woman’s life when bone health is particularly vulnerable:
Adolescence and Early Adulthood (Building Phase)
If you don’t build strong bones by age 28, you’ll never catch up. Yet many young women today aren’t building enough bone because:
- Energy deficits from dieting: The cultural pressure for women to be “teeny tiny” leads to chronic undereating and disrupted menstrual cycles. Without consistent estrogen, bones don’t develop properly. [^1]
- Sedentary lifestyles: A generation of kids raised on video games aren’t getting the weight-bearing activity needed to build strong bones. [^1]
- Over-exercising without adequate nutrition: Female athletes burning 10,000 calories a day without proper refeeding live in energy deficit, which sabotages bone development. [^1]
Research from the University of Wisconsin found that gymnastics builds the best bone because of the pounding, impact, and proper nutrition in those athletes. [^1]
Breastfeeding (Depletion Phase)
Breastfeeding is wonderful for babies, but it comes at a cost for mothers: women lose about 20% of their bone density in the first six months of breastfeeding. [^1]
Why? Because breast milk requires about 500 milligrams of calcium per day, pulled directly from the mother’s body. [^1]
If you’re not replacing that calcium through diet or supplementation, you won’t rebuild your bones. And if you have children in quick succession (common for women who start families later in life), you may never fully recover. [^1]
Menopause (Collapse Phase)
Around age 45, perimenopause begins. Estrogen and progesterone levels fluctuate wildly, then plummet. The result: accelerated bone loss, increased fracture risk, and loss of structural integrity. [^4]
After menopause, women can no longer rely on hormones for bone growth and maintenance. They must look for external stress: resistance training. [^4]
The Deadly Consequences of Weak Bones
Bone loss isn’t just about increased fracture risk. Falls and fractures are deadly in older adults.
Dr. Peter Attia shares a sobering statistic:
“Once you reach the age of 65, your mortality from a fall that results in a broken hip or femur is 15% to 30%. And of all the people who survive, 50% will never again regain the level of function they had before the injury.” [^5]
Read that again: a single fall after 65 has a 15-30% chance of killing you within a year. And if you survive, there’s a 50% chance you’ll need a cane or walker for the rest of your life.
Why do people fall? It’s not just balance. It’s a power deficit problem. When you trip or step off a curb unexpectedly, your body needs to react explosively to catch yourself. That requires fast-twitch muscle fibers and strong bones. These are the first to atrophy as you age. [^5]
How to Protect Your Bones (and Extend Your Life)
The good news: bone health is largely within your control, especially if you start early and stay consistent.
1. Resistance Training Is Non-Negotiable
Weight-bearing and resistance exercises trigger bone remodeling. When you put mechanical stress on your skeleton (through squats, deadlifts, jumping, or even just walking with a weighted vest), your bones respond by getting stronger and denser.
Dr. Vonda Wright emphasizes: “You need to bash your bones. You need to impact your bones. The mechanical stress of impacting bones, whether it’s jumping up and down, running…” [^6]
Compound movements are particularly effective because they:
- Load the skeleton across multiple joints
- Trigger lactate production (which also benefits the brain)
- Build functional strength that prevents falls
Women especially need resistance training because after menopause, they can’t rely on hormones for bone maintenance. Exercise provides the external stress necessary to keep bones strong. [^4]
2. Get Enough Vitamin D
Vitamin D is actually a hormone, not just a vitamin. It regulates over 5% of your genome and is critical for calcium absorption, bone health, immune function, and brain health. [^7]
Yet 70% of the U.S. population has insufficient vitamin D levels. [^7]
Why? Because vitamin D is made in the skin from UVB radiation from the sun. If you’re inside all day (working, commuting, gaming), you’re not making enough. [^7]
For strong bones, you need:
- Vitamin D (ideally from sun exposure or supplementation after testing your levels)
- Vitamin K2 (to ensure calcium goes into bones, not arteries)
- Magnesium (works synergistically with vitamin D) [^6]
Important: Get your vitamin D levels tested before supplementing. It’s a fat-soluble vitamin, and excessive supplementation can lead to too much calcium in the bloodstream (hypercalcemia), which has its own risks. [^8]
3. Prioritize Protein and Calcium from Whole Foods
You need about 1 gram of protein per pound of ideal body weight to build and maintain muscle, which in turn supports bone health. [^6]
For calcium, prioritize whole food sources:
- Dairy (yogurt, cheese, milk)
- Leafy greens
- Sardines with bones
- Fortified plant milks
- Prunes and dates
Avoid high-dose calcium supplements (especially above 1,000 mg/day), as some research suggests they may increase cardiovascular risk. Instead, focus on improving calcium absorption through adequate vitamin D and K2. [^9]
4. Start Early (But It’s Never Too Late)
The best time to build strong bones was in your 20s. The second-best time is now.
If you’re young, maximize your peak bone mass by:
- Engaging in weight-bearing activities
- Eating enough to support hormonal health
- Avoiding chronic energy deficits
If you’re midlife or beyond, protect what you have by:
- Doing resistance training 3+ days per week
- Supplementing with vitamin D (after testing)
- Ensuring adequate protein and calcium intake
- Avoiding prolonged sitting
The Bottom Line
Your bones are not just scaffolding. They’re metabolically active organs that:
- Produce hormones (like osteocalcin) that protect your brain, regulate blood sugar, and boost testosterone
- Grow new neurons in your hippocampus, supporting memory and learning
- Communicate with muscles to improve glucose metabolism
- Store critical minerals like calcium and phosphorus
- Determine your physical independence in old age
Women face unique challenges: lower peak bone mass, accelerated loss after menopause, and critical vulnerability during adolescence, breastfeeding, and midlife. Without intervention, bone loss leads to fractures, disability, and early death.
But the solution is clear:
✅ Resistance training (3+ days per week)
✅ Vitamin D (test your levels and supplement as needed)
✅ Adequate protein and calcium (from whole foods)
✅ Start early and stay consistent
Your bones are holding you up today. Make sure they’re strong enough to hold you up tomorrow.
References
[^1]: Dr. Vonda Wright, orthopedic surgeon and healthy aging expert, from The Diary Of A CEO: “The Ageing Doctor: These Are The Early Signs Of Arthritis, If You Run Don’t Do This, Start Now: The Secret Cause of Alzheimer’s”
[^2]: Dr. Andrew Huberman, neuroscientist and professor at Stanford School of Medicine, from Huberman Lab: “How to Use Exercise to Improve Your Brain’s Health, Longevity & Performance”
[^3]: Dr. Vonda Wright, from The Diary Of A CEO: “The Ageing Doctor”
[^4]: Dr. Stacy Sims, exercise physiologist and nutrition scientist, from research on women’s exercise and aging
[^5]: Dr. Peter Attia, longevity physician and author, from The Diary Of A CEO: “Anti-Aging Expert: Anti-aging Cure No One Talks About”
[^6]: Dr. Vonda Wright, from The Diary Of A CEO: “The Healthy Ageing Doctor: Doing This For 30s Will Burn More Fat Than A Long Run”
[^7]: Dr. Rhonda Patrick, biomedical scientist, from research on vitamin D and aging
[^8]: Dr. Rhonda Patrick, from The Knowledge Project: “Dr. Rhonda Patrick: Diet Essentials For Healthy Living”
[^9]: Dr. Pradip Jamnadas, cardiologist, from The Diary Of A CEO: “The Insulin & Heart Doctor”
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