One of the most common concerns of those starting a Paleo diet is that the diet is low in calcium. In fact, this is one of the biggest complaints from conventional medical professionals and dietitians: that by excluding dairy and grains, that we won’t be able to get adequate nutrients like calcium and vitamin D, and thus our bone health will suffer.
The illogical nature of this concern should be obvious – there are many cultures around the world who do not consume dairy products and yet are able to maintain healthy, strong bones for the duration of their lifetime. (1a, 1b)
In this article, I’ll use the latest research, anthropological data, and even some common sense to help you design your diet and lifestyle to protect your bones and keep them strong as you age.
Learn how to keep your bones strong naturally with #Paleo diet and lifestyle tips by Laura Schoenfeld, RD.
What Is Osteoporosis?
Before I talk about how to prevent osteoporosis and other bone disorders with diet and lifestyle, I’ll briefly explain the bone mineralization process in order to give some context to my recommendations.
As children’s bones grow, the remodeling process allows them to elongate and change shape to fit the needs of the adult body. When new forces and stresses are applied to a bone, remodeling is used to add new bone tissue where necessary and strengthen the bones to handle the new stresses.
Our bones are also our biggest storage organ for calcium, which is kept in a tight homeostatic range in our blood stream in order to provide appropriate calcium for important functions like nerve signaling, blood clotting, and muscle contractions. When our serum calcium drops, cells called osteoclasts break down the bone tissue to release calcium into the blood. When serum calcium is elevated, a healthy, well nourished body will use its osteoblasts to return that calcium to the bone reservoir.
Watch this short video for an excellent overview of the bone remodeling process:
Now that you understand how bone grows and changes, let’s talk about what can go wrong with this process. Osteoporosis, one of the most common bone density issues as we age, is when bone becomes more porous and thus more brittle as we age. Osteopenia is a precursor to osteoporosis, and both are diagnosed using bone mineral density scanning using a DEXA machine. Osteomalacia is a softening of the bones due to vitamin D deficiency, and is another cause of bone fractures.
Women are at especially high risk due to the role that estrogen plays in maintaining their bone mass; estrogen declines with age and is affected by many factors including diet, exercise, and stress. (3)
So now that we understand the physiology of bone growth, as well as its importance, let’s talk about how we can keep our bones strong using simple diet and lifestyle changes.
Calcium is a surprisingly controversial nutrient. The government’s guidelines for calcium intake range from 1,000 to 1,300 mg daily for adults, but some experts suggest that we only really need about 600-800 mg of calcium daily for healthy bones. (4, 5) Still others argue that the bioavailability of calcium from different foods will affect how much calcium you actually need to eat in order to get what you need on a daily basis. (6, 7)
While the science on calcium is controversial and far from decided, I generally recommend my clients get a minimum of 600 mg of calcium daily from their food, and ideally above 800 mg. Here’s a list of whole foods and their calcium content, starting with the best sources:
If you had two cups of leafy greens and a can of bone-in sardines in one day, you’d already have eaten around 840 mg of calcium. Add in some herbs and spices, and 2 ounces of almonds, and you’d be at the 1,000 mg mark easily.
(PS – Share this chart with any of your friends or family members who ask you where you get your calcium from on Paleo!)
Vitamins D, A and K2
If you’ve been following a Paleo diet for some time now, no doubt you’ve already learned about the role of the fat soluble vitamins A, D, and K2 in promoting bone health and ensuring proper absorption and utilization of the calcium we eat. But if you’re new to Paleo, you may have no idea why these nutrients are so essential, and you may not have even heard of Vitamin K2!
To keep things short and sweet, I’m not going to go into detail about these nutrients, as that would warrant its own blog post. Instead, for further information on the topic, I’ll recommend Dr. Kate Rheume-Bleue’s book Vitamin K2 and the Calcium Paradox, along with Chris Masterjohn’s article on how vitamin A does not cause osteoporosis when balanced appropriately with vitamin D. Both of these resources explain in detail the evidence that demonstrates the crucial need for a balanced intake of these three fat soluble vitamins in serum calcium balance and overall bone health.
Vitamin D should ideally come from appropriate sun exposure, and good blood levels to aim for year round are between 30-50 ng/dL. Some people need to supplement with vitamin D3 if they have dark skin and/or live far from the equator, or cannot spend adequate time outdoors to maintain appropriate levels.
Vitamin A in its preformed state primarily comes from liver, and you can eat 1/4 pound of liver per week or supplement with 1 tsp cod liver oil daily to get adequate intake. Egg yolks are also a good source of preformed vitamin A.
For vitamin K2, you can eat grass fed dairy fat like ghee and butter, goose and other poultry livers, fermented vegetables like sauerkraut, or natto, a traditionally fermented soybean product.
There are supplements that can help boost your intake of these three vitamins. Extra Virgin Cod Liver Oil from Rosita as my preferred cod liver oil product. For those who can’t tolerate that supplement, another supplement I frequently recommend is Nutricology’s Vitamin D3 Complete, which is a better choice for people with dairy intolerance or sensitivity to fermented foods.
Since magnesium is needed for an astonishing number of physiological functions in our body (more than 300!), and many of our modern behaviors deplete magnesium more rapidly, it’s imperative that we make an effort to keep our magnesium intake high: Chris and I recommend a minimum of 400 mg daily, and up to 800 mg for those with higher needs.
Magnesium is one of the few nutrients that we recommend supplementing with regularly. My favorite supplements are magnesium glycinate and magnesium malate, which are generally well tolerated and cause the least digestive side effects. (Please note: Magnesium supplementation is not appropriate for everyone. See these precautions and talk to your doctor or a dietitian before starting any supplements.)
Another largely unknown influence on bone health and the risk of osteoporosis is inflammation. Several different inflammatory cytokines have been implicated in the development of osteoporosis, and chronic inflammation is believed to be a major risk factor for the disease. (9)
Inflammation has many causes, but there are many diet and lifestyle factors that can influence the inflammatory process. Examples of this include a low omega-3 to omega-6 ratio in the diet, high consumption of refined cereal grains and sugar, and low intake of antioxidant rich plant foods. Fortunately, a Paleo diet is highly anti-inflammatory, especially when there is a strong focus on eating fatty fish and grassfed meats, copious amounts of plant foods, and generally avoiding refined grains, seed oils, and sugar.
For people who have an immune response to gluten, including those with celiac disease, strictly avoiding gluten is essential for preventing osteoporosis. As I just mentioned, inflammation is a significant factor leading to the development of osteoporosis, and whenever we eat foods that we have a strong immune response to, we are increasing the overall inflammatory state of our bodies. (10)
So it should come as no surprise that a decrease in bone density is one of the first symptoms of celiac disease, even in otherwise asymptomatic patients. (11) And the good news is that those who have reduced bone mineral density from previously undiagnosed and untreated celiac disease can significantly improve their bone strength simply by following a gluten-free diet. (12, 13)
Dairy As Tolerated
Like calcium, dairy is another hotly contested topic when it comes to promoting bone health. Our government recommends three servings of dairy per day for adequate calcium intake, while many plant-based diet advocates suggest that a high dairy intake actually causes osteoporosis. These two recommendations couldn’t be more polar opposite, and it’s no wonder people are confused about the role of dairy in a healthy, bone building diet.
Chris wrote an excellent article on dairy and osteoporosis, and explained that the majority of the evidence suggests that dairy is generally positive when it comes to its effects on bone health. As I discussed earlier, you certainly don’t need dairy to get adequate calcium and vitamin D to build healthy bones, but some amount of full fat, organic dairy intake can potentially make your bones stronger.
That said, much like gluten, there are many people whose bodies mount an immune response to the proteins in dairy like whey and casein. I’ve seen many people in my dietetics practice who have tested positive for immunogenic activity against dairy proteins, and these people should definitely avoid dairy for better bone health.
Ultimately, the role of dairy in bone health is highly individual. If you’re not sure if dairy is an appropriate food for you, consider working with a nutritionist who can help you determine your personal tolerance to high quality dairy foods.
What many people forget about the structure of bones is that around 25-30% of the dry weight of bone is made of collagen proteins. Evidence suggests that the strength of our bones is highly dependent on the quality of the collagen matrix, particularly the cross-linking of collagen, thus it would make sense that supporting collagen formation would be important in keeping bones strong as we age. (14, 15)
In order to have good collagen formation, you need amino acids glycine, proline and lysine, along with adequate amounts of vitamin C for the hydroxylation of these amino acids. While our bodies can produce glycine, proline and lysine from any dietary protein, there is some evidence that these amino acids can be considered “conditionally essential” and thus we would benefit from consuming them in our diets. (16)
This means eating lots of bones, joints, tendons, and skin from animals, either by making bone broth regularly, consuming gelatin frequently, and following a nose-to-tail eating pattern that our ancestors would have done regularly to receive all those bone broth benefits. Also, getting plenty of vitamin C from fresh fruits and vegetables will help ensure proper collagen formation. If you can’t eat a lot of plant foods for some reason, supplementing with vitamin C may be helpful. Iron and copper are two minerals that are required for collagen production, and you can get both of those nutrients in liver.
Read this article for more information about how nutrition can affect collagen production.
This is another topic that could be a whole blog post in itself, and mainly applies to women who are overtraining and undereating. There is a common syndrome in female athletes called the Female Athlete Triad, and it can affect any woman who is training hard and not fueling herself with an appropriate amount of calories. We discussed this condition on a recent podcast, and I believe it’s an enormously under-recognized issue in the Paleo community, where there are many women on low carb and/or low calorie diets while simultaneously participating in high intensity training programs like CrossFit or running long distances.
If you’re concerned you have this condition, I strongly recommend working with a nutritionist to help you ensure you’re eating an appropriate amount of food and helping you regain a normal menstrual cycle if you’ve lost yours.
Some people are concerned that a high intake of animal protein on a Paleo diet will cause acidification of the body, leading to bone demineralization. However, observational studies have not found a correlation between dietary acid load and bone mineral density (BMD) or fracture risk. And while high protein diets are associated with increased calcium in the urine, there’s no evidence of a net negative impact on calcium status from a high protein intake. In fact, animal protein, the most acid-forming food of all, has been associated with better bone health. Chris has covered this topic extensively in his series on the Acid-Alkaline Myth, and I strongly recommend reading those posts if you’re at all concerned with the effect of meat consumption on bone health.
Diet isn’t the only factor that influences bone strength. Doing the right type and amount of physical activity on a regular basis is just as important to maintaining healthy bone density. The best type of exercise for bone strength is weight bearing exercise, the best of these being strength training with relatively heavy weights. The stress put on your bones during the exercise stimulates the remodeling process described in the beginning of this article. Doing moderate weight lifting exercises a few times per week has been shown to significantly increase bone density, particularly in postmenopausal women. (17, 18, 19)
Running is often touted as another way to build bone density, with a recent study suggesting that it may be even more effective for building bone mass than weight lifting. (20) On the flip side, other studies have shown that long distance runners actually have lower bone mineral density than those who are sedentary. (21, 22) I believe this has more to do with the increased inflammation from catabolic exercise combined with the hormonal effects of overtraining, particularly in women. Running shorter distances and ensuring proper nutrition is key, and mixing endurance exercise with resistance exercise is likely the best way to promote bone health.
Melatonin affects the actions of osteoblasts and osteoclasts, interacts with other hormones like estrogen to augment bone remodeling, and functions as a potent antioxidant, protecting bone cells from oxidative stress and inflammation.
The most important way to keep melatonin secretion functioning optimally is to get your circadian rhythms entrained onto an appropriate 24-hour cycle. The best way to do that is to limit your exposure to artificial light at night, and to ensure you get adequate daylight during the day. Committing to 8 hours of high quality sleep in a cool, dark room also helps boost melatonin. And here are several ways your diet can improve your sleep.
Our new 14Four program also covers concise recommendations for improving sleep, so join us if you’re interested in learning more.
Stress is another factor of good health that generally gets ignored by those more focused on diet and exercise. And like sleep, stress levels can directly impact your bone health. It’s well known that the long term use of corticosteroid medications causes bone loss and can lead to osteoporosis. (24, 25) However, high cortisol from stress could potentially lead to similar effects on bone density. Cortisol indirectly acts on bone by blocking calcium absorption which decreases bone cell growth, and even a short bout of elevated cortisol may cause a decrease in bone mass. (26) Several studies suggest that high cortisol may lead to decreased bone density. (27, 28, 29, 30)
Recommended techniques include yoga, meditation, deep breathing, and positive social interaction. We’ve dedicated a significant amount of the new 14Four program to stress management, so I recommend signing up if you’re interested in learning how to make stress management a regular, committed practice.
Tobacco and Excess Alcohol
I’m probably preaching to the choir here, but it’s important to remember that both cigarette smoking and excess alcohol consumption have been linked to reduced bone density. (31, 32) So if you are smoking or regularly drinking in excess, stopping those habits as soon as possible should be a priority for keeping your bones healthy.
What About Calcium Supplements?
Though calcium supplementation is a common recommendation by conventional doctors and dietitians for patients with reduced bone density, there is a lot of evidence to suggest that this is inappropriate and potentially unsafe advice. Chris wrote a comprehensive review of the dangers of calcium supplementation, which will likely do more harm than good for most people. There are very few people who should even consider calcium supplementation, and the majority of the population should have no trouble getting adequate calcium intake through food, as I explained how to do at the beginning of this post.
Conclusion: Paleo IS a Bone Building Way of Life!
So the next time a friend, relative, or even medical professional expresses concerns over your bone health with your dairy-free, grain-free Paleo diet, send them this article!