If I had to guess, I’d bet you think that there are no effects of aging on bones. And I blame museums!
Everywhere you look in a museum: bones. Bones of dead animals. And of extinct animals. Bones that, after millions of years, still look like bones.
It gives you this feeling that bones can’t change. That they are inert. That they are dead.
Now, to be fair, it isn’t really the museums’ fault. At least not all their fault. After all, you never see any kind of bone if the animal it belongs to is still alive (unless you’re a vet, surgeon or some kind of trauma doctor), so you’re naturally inclined to associate bones with death, anyway. Not to mention all the fun cultural quirks that work to reinforce that natural inclination — skull-and-crossbones meaning poison, skeleton decorations for Halloween, the phrase “bone dry”, etc.
There is just something about the million-year-old skeletons, though, that somehow really drives it home. For me, anyway.
Unfortunately, the feeling that age-old skeletons in museums give you about bones couldn’t be further from the truth. Though they can be fossilized into something unchangeable under certain conditions outside your body, inside your body, bones are living, dynamic tissues, just as vulnerable to change as any of your other organs.
This includes changes associated with aging.
The Effects of Aging on Bones
While some organs of the body undergo lots of changes as you age, your bones undergo essentially just one: demineralization.
Aging and Other Organs: Tools for Life-Long Wellness: Understanding How and Why You Age
Demineralization is a complex process that has huge consequences for the health of your bones. See, bone tissue is made up primarily of two components — a sophisticated three-dimensional network of proteins and a hard, mineral complex.
The protein network (mostly comprised of collagen) serves as a flexible scaffolding which is then layered with stiff, strong, durable mineral crystals (made almost entirely of calcium phosphate). These two components — collagen and calcium phosphate — work together to make bones both compressible (to help them absorb forces) and rigid (to help support your movements and body weight).
As you can imagine, losing the mineral component of your bone causes half of that equation to break down on you. Your bones lose some of the strength and durability they need to carry your body weight and support your movements. This puts you at risk of damaging or even breaking your bones just going through your normal life.
This risk can become extreme of demineralization progresses to a condition called “osteoporosis.” In osteoporosis, bones are so demineralized that great big open holes form in the bone (the right side of Figure 1), making them extremely brittle and easily breakable.
Figure 1: Normal vs. Osteoporotic Bone
Bone Comparison of Healthy and Osteoporotic Vertebrae by Turner Biomechanics Laboratory is in the Public Domain.
Bone Fractures and Health
Not only is this a problem because having a broken bone is painful, messes up your life and is, in general, just no fun, but broken bones in old age are also a huge risk factor for premature death.
Up to around 16% of people who develop a broken hip, for example, die within 4 months of the injury, and 38% within 2 years. It’s usually not the broken hip itself that leads to death, of course, but the break frequently directly contributes to the conditions that caused death. For example, those who suffer a hip fracture can experience fatal complications from hip-repair surgery. Or they can catch a deadly infection while staying at the hospital. Or see a lethal worsening of their metabolic diseases (like heart disease or diabetes) because they are unable to undertake any kind of exercise at all.
Clearly, demineralization is bad news for both your bones and you. So, why does it happen when you age?
To answer that question, we have to take a step back and look at how healthy bones normally stay mineralized!
Healthy Bone Mineralization
Keeping bones mineralized is a pretty complex process. See, every minute of every day, there are two sets of cells working on the mineral crystals in your bones.
One group, called osteoblasts, are producing new collagen network structures and loading them with calcium phosphate “seeds”, allowing the network to be mineralized. They are making new bone.
The second group, called osteoclasts, are producing acid, breaking down the calcium phosphate crystals and collagen molecules. They are breaking down old bone.
Now, normally, the signals that activate your osteoclasts and osteoblasts are in perfect balance, so that your bones stay perfectly mineralized. When you age, though, these signals become imbalanced and your osteoclasts start outstripping your osteoblasts. They start breaking down your bones far, far faster than your osteoblasts can replace it.
What are the signals that get out of whack as you age?
There are several. Let’s check them out one at a time.
Low Calcium Levels
Calcium levels in your blood are one of the most important signals regulating your bone cells. You might suspect that it’s the osteoblasts that respond most strongly to changes in calcium availability. After all, it’s tricky to make bone mineral crystals containing calcium when there isn’t much calcium around. Actually, though, it’s the osteoclasts that keep an eye on your calcium levels.
Your osteoclasts know that calcium is important for your whole body, not just your bones. They know that if there isn’t enough calcium in your blood for your heart and brain to use, it can be life-threatening pretty quickly. So, if your osteoclasts notice that your blood calcium levels are creeping down, they start chopping up bone and releasing the calcium back into your blood. It’s sacrificing a little bit of your bone to keep your whole body healthy (and alive!).
This is an important fail-safe to keep your heart and brain healthy in emergencies, and normally, it’s a pretty short-lived process. As soon as you eat a calcium-rich meal, the osteoclasts notice a rise in blood levels and go back to normal bone-break-down-rates. There is only a problem when low calcium levels become chronic, which is something that is much more likely to happen as you age.
Because of changes in your skin and diet.
When your skin ages, it becomes less able to use sunlight to convert pre-vitamin D into active vitamin D. This means that, over time, the levels of active vitamin D in your body drop off (unless you get it from food or vitamin D supplements). This is a problem for your blood calcium levels (and your bones) because one of the key jobs of vitamin D is helping your intestines absorb calcium from your food. The lower your vitamin D levels get, the less calcium you can get into your blood, regardless of how many calcium-rich foods you pack into your diet.
Unfortunately, many older individuals aren’t even getting enough calcium in their diet to begin with. Age-related difficulties with chewing, swallowing and digestion lead older individuals to avoid hard-to-digest foods — like fresh fruits, vegetables, nuts and seeds — which, unfortunately, are some of the best sources of calcium! Combine this with a natural drop off in appetite that usually accompanies aging and you have a recipe for very low calcium intakes and even lower blood calcium levels, long-term.
Low Sex Hormone Levels
Both estrogen and testosterone (the female and male sex hormones, respectively) affect the mineralization of your bones. Estrogen binds to special receptors on the surface of osteoclasts, telling them to turn off and stop breaking down bone. Testosterone, on the other hand, binds to special receptors on the surface of osteoblasts, telling them to turn on and make more new bone.
During your reproductive years, these signals work together perfectly to help protect your bones. Healthy levels of testosterone keep osteoblasts building away and healthy levels of estrogen keep osteoclasts relatively subdued.
As you age, though, and leave your reproductive years, the levels of these hormones in your body naturally drop off. This is, of course, more dramatic for women during and following menopause, but men also see a dip in their testosterone as they age. Without enough sex hormones, these regulcating signals to your bone cells are lost. This lets osteoclasts turn on and osteoblasts turn off — exactly the combination that leads to demineralization.
Low Muscle Mass
Yet another powerful regulator of bone cell activity is physical movement by your muscles. Osteoblasts are activated by pressure on your bones from your muscles squeezing down on them. This can be walking, running, climbing stairs, lifting weights, or just jumping around with your grandkids! (Anything that makes your muscles really contract.) Basically, the more rough-housing shenanigans you get up to, the stronger your osteoblasts make your bones!
Unfortunately, just like the signals from calcium and sex hormones, these protective signals from your muscles naturally drop off as you age, as well.
This is because, as you get older, your muscles usually become smaller and weaker. This is driven by changes in your body’s hormone levels (like those dips in estrogen and testosterone that I mentioned before, and in one other hormone called “insulin-like growth factor 1”). Though you can slow this process down some by exercising and sending plenty of exercise-driven signals to your muscles to stay strong, you can’t really keep all the muscle mass you had when you were young.
This is a problem for your bones because smaller, weaker muscles simply can’t squeeze down on them with as much force. Less muscle force leads to less osteoblast activation, giving your osteoclasts yet another leg up in breaking down your bones.
Chemicals released from your immune cells in response to injury or danger are also powerful regulators of your bone cell function.
These chemicals, called “cytokines” or “inflammatory mediators” bind to special receptors on the surface of osteoclasts, activating them to start breaking down bone. This response is thought to be intended to protect your bones, since a bone injury (which releases the same chemicals) heals better if your osteoclasts are first turned on to clean up any jagged edges or splinters before your osteoblasts try to close the wound.
Unfortunately, changes in your immune system as you age often lead to a condition called “chronic inflammation.” In chronic inflammation, your immune cells release cytokines even when you don’t have an infection or injury anywhere in the body at all (let alone specifically in the bone), and they do so for long periods of time. This bombards your osteoclasts with activating signals, throwing the activity of your bone cells even more off balance.
Bones: Accidental Aging Victim
It’s really unfortunate that there are so many unpleasant effects of aging on bones. After all, your bones themselves aren’t doing anything wrong! They are just responding to the signals the rest of your body is sending over. It’s just that the signals are all messed up!
Of course, this positively begs the question, “Is there anything I can do to nip some of these effects of aging on signals to my bones in the bud?” Luckily, there is! It looks like there are few simple dietary and lifestyle tweaks you can make that may be able to help shore up your bones against aging!
Protecting Your Bones
Researchers have identified three key lifestyle tweaks that can help prevent the effects of aging on bone. Let’s check them out one at a time!
Engage in Weight-Bearing Exercise
The first effective way to help keep your bones from demineralization as you age is to exercise. Remember how I mentioned that your muscles tend to become smaller and weaker as you age? While this is true (and you probably cannot keep all the muscle mass you had when you were young) regular physical exercise can help slow down your loss of muscle, keeping signals from your muscles to your osteoblasts flowing stronger, longer!
For exercise to be really effective at protecting your bones, though, you need to make sure to do two things:
- Choose an exercise that requires your muscles to really bear weight. Walking, running, climbing or weightlifting are all great options. Non-weight-bearing exercises, though great for your health in general, aren’t as effective at activating your osteoblasts.
- Stick with your exercise long-term. Studies show that once you stop working out, bone demineralization picks right back up where it left off.
Eat a Bone-Healthy Diet
The second lifestyle tweak you can make to help protect your bones as you age is to fill your diet with foods rich in bone-protective vitamins and minerals. Vitamin D (found in meat and dairy), calcium, vitamin K, magnesium and potassium (found in fruits and vegetables, especially leafy greens, and nuts) are all critical for helping keep your bones healthy! Loading your plate, three times a day, with whole, fresh, vitamin- and mineral-rich foods can only help protect your bones!
Add Bone-Protective Supplements
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If you want to boost your intake of bone-protective nutrients further, supplements may be useful for you.
Depending on your needs, your lifestyle and your diet, there are several supplements that may fit the bill!
If you’re not comfortable taking a high-dose single nutrient just yet, probiotics may be a great option for you!
Probiotics are supplements containing living, healthy microorganisms you find living happily in your gut and that work with your body to help you stay healthy. One of the ways they do this is by boosting your ability to absorb vitamins and minerals. This includes the vitamins and minerals you need to build new, strong bones.
See, probiotic bacteria help you break down your food more efficiently. This releases calcium, magnesium, potassium ions out of the fibers and cells they are trapped, so you can absorb them into your bloodstream. Additionally, probiotic bacteria actually make important bone-protective vitamins that you can absorb and use, particularly vitamin K.
Learn more: How Probiotics Protect Bone Health
Combined, these effects make probiotics a great way to naturally boost levels of bone-protecting vitamins and minerals in your body. They just make you more efficient at using what you’ve already got!
If probiotics sound like an interesting option to you, we recommend finding a brand that contains the one or more of the following bacterial strains, which have been shown to improve mineral absorption from food and protect bone health in human, animal or cell studies: Lactobacillus helveticus, Lactobacillus salivarius, Lactobacillus reuteri, and Bifidobacterium longum.
Looking for shopping inspiration? NatureMyst’s Controlled Release Probiotic supplement contains all four of these bone protective bacterial strains and has rave reviews from customers who’ve purchased it on Amazon.
For people entering their golden years, taking a vitamin D supplement may be a useful tool for protecting their bones. As I mentioned above, your vitamin D levels naturally decline as you age, due, primarily, to changes in how well your skin can produce vitamin D from sunlight. This can be particularly problematic if you live north of the 40th parallel (around San Francisco in the United States). Low levels of sunlight during at these latitudes mean that you can’t produce vitamin D in the winter at all.
Luckily, study after study has shown that taking a vitamin D supplement of at least 2,000 IU per day is effective at bringing blood levels of vitamin D back up into the healthy range, helping protect your bones from demineralization (and, potentially, the rest of your body from a whole host of other conditions, to boot!).
If a vitamin D supplement sounds like it’s up your alley, we recommend Fertile Moon Liquid Vitamin D3. Our favorite vitamin D supplement, Fertile Moon contains 2,000 IU per dose, contains the most highly effective form of vitamin D (D3, which is more easily used by your body than the D2 form), and is ridiculously well-reviewed by consumers on Amazon (96% 5-star ratings!).
One final supplement which may be helpful for protecting your bones is vitamin K, especially if you struggle to get enough dark, leafy greens or beans — the main sources of vitamin K — in your diet.
Typically, doctors recommend high doses of vitamin K (45 mg/day) to help prevent osteoporosis in the beginning stages of the disease. Such high doses, however, can have serious side effects, so you need to have a prescription from your doctor to take them.
Luckily, there is now some evidence that much lower doses, at least of of vitamin K2 (180 micrograms per day) may be enough to help prevent bone loss.
Oddly, there aren’t many supplements on the market that offer vitamin K2 at this scientifically-tested dose, so you may have to do some hunting if you’re looking for one. If you’d like a hand-up, after our digging, we found and recommend Evolved Vitamin K2 MK-7. This supplement contains only vitamin K2 and the coating contains no unnecessary fillers and the product. Plus, it has been well-received by customers, with over two-thirds giving it a 4-star rating or higher!
A Supplement Not to Take: Calcium
For a long time, doctors advised postmenopausal women to take a calcium and vitamin D supplement to protect their bones. Many, many women did so, which gave researchers lots of data concerning calcium supplements and women’s health!
When researchers analyzed the data to see how well calcium helped protect women’s bones, however, they found something upsetting. Not only did women who took calcium supplements not have a decreased risk of osteoporosis and broken bones, they had an increased risk of heart attacks and strokes.
Since this data has come out, the U.S. Preventive Medicine Task Force has changed their official recommendations to not supplement with calcium to try to prevent osteoporosis (unless otherwise instructed by your doctor).
Take Home Message
Though many of us think of bones as inert, they are highly dynamic organs. Constantly being broken down and remade, bone is sensitive to signal changes to the cells responsible for the remodeling processes. Changes in several signals that naturally accompany aging lead to the effect of aging on bone: demineralization. Demineralization can progress to osteoporosis, bone fractures and an increased risk of premature death. Increasing your levels of exercise, filling your plate with bone-healthy fruits and vegetables and adding bone-health-promoting supplements to your daily routine can help stave of demineralization.