Any time we mention the whole “we don’t do dairy” thing, we inevitably get The Question:
“But what about calcium?”
The Question is generally coming from the perspective that strong, healthy bones are important, and calcium builds strong healthy bones.
We do not disagree.
But despite what the Got Milk? ads would lead you to believe, the whole “strong bones” thing is a lot more complicated than that. There are three fallacies when it comes to the dairy/calcium/bones triad.
- Building strong, healthy bones depends only on calcium
- Your calcium intake is the only thing that matters
- Dairy is the only good source of calcium
Let’s break these down one at a time.
1. BONES = CALCIUM
Bone development is influenced by a number of factors, including nutrition, exposure to sunlight, hormonal secretions, and physical exercise. Of the nutrition component, calcium is seen as the most critical factor. And there’s no denying that calcium is important for bone health – calcium is the substance that gives bone strength, like bricks do for a building.
But bones need more than just calcium to grow and stay strong. Vitamin C, “vitamin” D3 (which is technically a hormone), and vitamin K, along with minerals like magnesium and phosphorous, all play roles in bone development.
- Vitamin C helps increases calcium absorption, and helps us form the optimal structure for bone strength.
- Vitamin D3 is necessary for the proper absorption of calcium in the small intestine. In the absence of adequate amounts of this vitamin, calcium is poorly absorbed, the bone matrix can become deficient in calcium, and the bones are likely to grow weak.
- Vitamin K has been linked to the cells that generate bone, and produces a specific protein that serves to “fix” calcium in place. It also inhibits other cells from breaking down bones. Observational studies have demonstrated a relationship between vitamin K and age-related bone loss (osteoporosis), such that inadequate vitamin K may increase your risk of fractures.*
- 60% of the magnesium in our bodies is found in our bones, in combination with calcium and phosphorus. Magnesium improves bone mineral density – and not getting enough magnesium may interfere with our ability to process calcium.
- Phosphorous supports building bone and other tissue during growth. About 85% of the phosphorus in our bodies is found in our bones, and phosphate makes up more than half of our bone mineral mass.
*There is also evidence that vitamins D and K work synergistically on bone density.
But it’s not just dietary factors that play into strong, healthy bones! Your hormones and inflammatory status also play a role. (That should not surprise you at this point.)
- Chronically elevated blood sugar (hyperglycemia) enhances the activity of cells that break down bone, and reduces bone density.
- Chronically elevated cortisol accelerates bone breakdown, and inhibits the activity of bone-building cells.
- Reduced estrogen levels (especially in post-menopausal women) upsets the normal balance between bone creation and breakdown, making bones more brittle and increasing the risk of fractures.
- Systemic inflammation and the resultant effects (free radicals, and an inflammatory marker called homocysteine) cause an accelerated breakdown of bone and inhibits the formation of new bone cells.
So it’s clear that strong, healthy bones depend on more than just calcium, and ensuring a diet and lifestyle that included an adequate amount of all of these vitamins and minerals – not just calcium – are necessary for bone growth and maintenance.
2. WE JUST NEED TO TAKE MORE
If first mistake is thinking that bone health is all about calcium, the second is believing our intake of calcium is all that matters. If this was true, then how do you reconcile this?
The United States has one of the highest rates of osteoporosis in the world,
despite having one of the highest calcium intakes.
It makes no sense… unless there’s more to the story than how much calcium we’re taking in. It’s also about how much we’re able to absorb, and retain. And factors like our dietary habits, our lifestyle, and the aging process all contribute to calcium absorption and retention.
- The phytates in foods like whole grains and legumes form complexes with the calcium and other minerals in the plant. This renders the calcium virtually impossible to absorb, and limits its bioavailability (the amount that can be effectively absorbed and used by the body).
- Whole grains may also promote a loss of vitamin D, a critical element of bone health. Low vitamin D3 levels (from diet and a lack of daily exposure to sunshine) inhibits calcium absorption.
- Stress affects HCL production in the stomach (and impacts normal digestion), which can have a negative effect on calcium absorption.
- Age also negatively impacts calcium absorption – on average, adults absorb about 20% less calcium than children.
- On the other hand, adequate protein in the diet increases calcium absorption and stimulates the production of hormones that promote new bone formation. This effect is more than sufficient to counter the increased urinary excretion of calcium observed upon increased protein consumption.
Finally, one additional note: vitamin D3 and K are both fat soluble – meaning they require some fat to be absorbed in the bloodstream. So a low fat diet (like the kind we’ve all been advised to eat for the last 20 years) may impair your body’s ability to absorb these two vitamins, which can also diminish bone health.
We told you it was complicated.
THE SUPPLEMENT STORY
These factors are exactly why all the calcium supplementation we’ve been doing just isn’t working to prevent osteoporosis and bone fractures. See, osteoporosis isn’t caused by a lack of calcium. And studies show that calcium intake alone does not prevent fractures due to bone loss. Taking calcium supplements gives you a short-term boost in bone density, but over time, your hormones (again!) will work against the extra calcium, and potentially leave your bones more brittle than before.
Bone density drugs (bisphosphonates) like Fosamax and Boniva aren’t much better. These drugs deposit a long-lasting compound in the bone, giving it the appearance of greater density, but do not build the same type of bone “matrix” that actually makes bones stronger. (Increasing bone density is not synonymous with strengthening bones.) This can result in “dense” bones that are too brittle to withstand everyday activities.
Finally, too much calcium is just as bad as not enough, in terms of our overall health. This excess of calcium generally comes from a combination of dairy plus calcium supplements plus the calcium added to a variety of products, from antacids to orange juice to cereals. Too much calcium increases the risk of developing dangerously high levels of calcium in the blood, which can result in impairment of kidney function, kidney stones, high blood pressure, and may increase your risk of heart disease and heart attack. Furthermore, recent studies suggest that taking calcium supplements actually increases the risk of “cardiovascular events” (translation: risk of heart attack).
3. YOU DON’T NEED MILK
Though we’ve just established that calcium, and your calcium intake, are not the only factors when it comes to bone health, a “just right” calcium balance is still necessary for overall health (bone and otherwise). But it’s high time we correct the “facts” promoted by years of industry-sponsored marketing.
Dairy is not the only good source of calcium.
You can find calcium (in bioavailable forms and significant amounts) in a wide variety of non-dairy, nutrient-dense foods, including vegetables, meat and seafood, nuts and seeds.
- Vegetable sources of calcium include kale, spinach (cooked), collard greens, mustard greens, turnip greens and bok choy, and sea vegetables like nori.
- Meat and seafood sources include organ meats, bone broth, small fish (like sardines), shrimp, oysters and canned salmon (with bones).
- Nut and seed sources include almonds, hazelnuts and walnuts.
THE POWER OF GREEN
It’s not just that you’ll find some calcium in these foods – it’s that the calcium in vegetable sources may prove more bioavailable (useful to the body) than the stuff you get from milk. One study compared the absorption of calcium from kale with the absorption from milk – and found kale the clear winner. (Yay, kale!) And recent studies have shown that plant-sourced calcium in particular increases bone mineral density and reduces the risk of osteoporosis.
This is likely not just due to the calcium content of the plant – the complement of other vitamins, minerals and phytonutrients found in veggies exert work synergistically to promote additional beneficial effects on bones.
Yet another reason to eat your greens.
Your body likes balance. Remember Goldilocks? Not too little, not too much… just right. And calcium doesn’t work in a vacuum, so too much calcium means your body is forced to compensate by adjusting levels of other vitamin and mineral stores, leaving you even more out of balance.
So, how do you build strong, healthy bones without dairy and without supplements? The short answer is, just follow our guidelines! We’ve built a healthy variety of micronutrition and a healthy hormonal balance into our plan. But if you’re looking for the specifics of our strategy, here’s the take-home.
Building strong, healthy bones on a Paleo diet
- Embrace a diet designed to promote a healthy hormonal response and minimize systemic inflammation.
- Eat a wide range of nutrient-dense foods (specifically dark, leafy greens and bone broths) to ensure adequate intake of all of the vitamins and minerals necessary for bone health.
- Avoid foods (like whole grains and legumes) that contain compounds that limit our body’s ability to absorb minerals.
- Eat a moderate protein diet (from animal sources) to aid in calcium absorption.
- Ensure a healthy daily dose of vitamin D3, ideally from sunshine, or via supplementation.
- Consider supplementing with magnesium, an important mineral co-factor in which most Americans are deficient due to dietary habits, depleted soil and fluoridated or filtered water.
- Include adequate dietary fat, to ensure the absorption of bone-building vitamins D3 and K.
For all of you overachievers, here’s your special bonus tip for building strong, healthy bones – pick up something heavy. Weight-bearing physical activity and strength training has long been linked to improved bone density. The compression forces of daily activity stress our bones in a healthy way. Our bones respond by building more supportive substances into the bones to structurally bear load. On the other hand, if we fail to stress our bones in this fashion (with a sedentary lifestyle, or failure to use weights in our exercise routine, our bones will slowly waste away. In other words, as was spoken by Hippocrates, “That which is not used, wastes away.” Or, as we like to say, use it or lose it.
Even if you follow all of our recommendations, however, you’ll find that you’re probably still not getting as much calcium as the powers that be (the US RDA) tells you is necessary.
We’re not that concerned.
Remember, it’s not about how much calcium we’re taking in – it’s about all of the other aspects we’ve just discussed. And studies support the fact that you probably don’t need as much calcium as you think, if all of your other factors are in line.
So skip the milk, eat your greens, get some sunshine and exercise regularly and enjoy all of the health benefits of a nutrient-dense, anti-inflammatory, hormone-optimizing diet – including strong, healthy bones.
Got Milk? is a registered trademark of the California Milk Processor Board.
More than just calcium: Other Nutrients and Bone Health at a Glance. niams.nih.gov. National Institutes of Health. Dec 2004. Web.
Vitamin K and bone loss: Feskanich D, Weber P, Willett WC, Rockett H, Booth SL, Colditz GA. Vitamin K intake and hip fractures in women: a prospective study. Am J Clin Nutr 1999;69(1):74-79
Bügel S. Vitamin K and bone health in adult humans. Vitam Horm 2008;78:393-416
Magnesium: Abraham GE, Grewal H. A total dietary program emphasizing magnesium instead of calcium. Effect on the mineral density of calcaneous bone in postmenopausal women on hormonal therapy. J Reprod Med 1990;35(5):503-7
Vitamins D and K work together: Adams J, Pepping J. Vitamin K in the treatment and prevention of osteoporosis and arterial calcification. Am J Health Syst Pharm 2005 Aug; 62 (15): 1574-81
Tanaka, K, Kuwabara, A. Fat soluble vitamins for maintaining bone health. Clin Calcium 2009 Sep; 19(9):1354-60
Schaafsma A, Muskiet FA, Storm H, Hofstede GJ, Pakan I, Van der Veer E. Vitamin D(3) and vitamin K(1) supplementation of Dutch postmenopausal women with normal and low bone mineral densities: effects on serum 25-hydroxyvitamin D and carboxylated osteocalcin. Eur J Clin Nutr 2000 Aug; 54 (8): 626-31
Okano T. Vitamin D, K and bone mineral density. Clin Calcium 2005 Sep; 15(9):1489-94
Weber P. Vitamin K and bone health. Nutrition 2001 Oct;17(10):880-7
Free radicals and bone health: Watkins BA et al, “Importance of Vitamin E in Bone Formation and in Chondrocyte Function” Purdue University, W. Lafayette, IN 47907
Blood sugar and bone health: Burckhardt Peter, Dawson-Hughes Bess, Weaver Connie M. Nutritional Influences on Bone Health. New York: Springer, 2010. Print.
Cortisol and bone health: Talbott Shawn. The Cortisol Connection. Alameda: Hunter House, 2007. Print.
Homocysteine and bone health: Cordain Loren. The Paleo Answer. Hoboken: John Wiley & Sons, 2012. Print.
United States/calcium: Cordain Loren. The Paleo Answer. Hoboken: John Wiley & Sons, 2012. Print.
Whole grains and vitamin D: Cordain Loren. The Paleo Answer. Hoboken: John Wiley & Sons, 2012. Print.
Mellanby, Edward. The Rickets-Producing and Anti-Calcifying Action of Phytate. J. Physiol 1949;109:488-533
Batchelor A J, Compston J E. Reduced plasma halflife of radio-labelled 25-hydroxyvitamin D3 in subjects receiving a high-fibre diet. Brit J Nutr 1983;49:213
Clements Mr, Johnson L, Fraser Dr. A new mechanism for induced vitamin D deficiency in calcium deprivation. Nature 1987;324:62-65
Age and calcium absorption: Heaney Robert P, Recker Robert R, Stegman Mary Ruth, Moy Alan J. Calcium absorption in women: Relationships to Calcium intake, Estrogen status, and age. J Bone Min Res August 1989;4:(4)469–475
Calcium does not prevent bone fractures: Freskanich D, et al., Milk, dietary calcium, and bone fractures in women: a 12-year prospective study. Am J Pub Health 1997 Jun; 87(6): 992-997
Cumming RG, et al. Case-control study of risk factors for hip fractures in the elderly. Am J Epidem 1994 Mar 1; 139(5): 493-503
Grant AM, et al. Calcium/vitamin D not effective for secondary prevention of fracture. Lancet 2005; 365:1621-1628
Too much calcium: Patel AM, Goldfarb S. Got Calcium? Welcome to the Calcium-Alkali Syndrome. JASN September 1 2010; (21):9,1440-1443
Bolland Mark J, Avenell Alison, Baron John A, Grey Andrew, MacLennan Graeme S, Gamble Greg D, Reid Ian R. Effect of calcium supplements on risk of myocardial infarction and cardiovascular events: meta-analysis. BMJ 2010;341:c3691
Bolland Mark J, Grey Andrew, Avenell Alison, Gamble Greg D, Reid Ian R. Calcium supplements with or without vitamin D and risk of cardiovascular events: reanalysis of the Women’s Health Initiative limited access dataset and meta-analysis. BMJ 2011;342:d2040.
Calcium from kale: Heaney RP, Weaver CM. Calcium absorption from kale. Am J Clin Nutr 1990; 51:656-657
Plant calcium in particular: Park HM, Heo J, Park Y. Calcium from plant sources is beneficial to lowering the risk of osteoporosis in postmenopausal Korean women. Nutr Res Jan 2011;31(1):27-32
“Go Green for Bone Health.” Taste For Life. May 2011:6. Print.
Tucker Katherine L, Hannan Marian T, Chen Honglei, Cupples L Adrienne, Wilson Peter WF, Kiel Douglas P. Potassium, magnesium, and fruit and vegetable intakes are associated with greater bone mineral density in elderly men and women. Am J Clin Nutr April 1999;69(4):727-736
New Susan A, Robins Simon P, Campbell Marion K, Martin James C, Garton Mark J, Bolton-Smith Caroline, Grubb David A, Lee Sue J, Reid David M. Dietary influences on bone mass and bone metabolism: further evidence of a positive link between fruit and vegetable consumption and bone health? Am J Clin Nutr Jan 2000;71(1):142-151
Magnesium: Marier JR. Magnesium Content of the Food Supply in the Modern-Day World. Magnesium 1986;5:1-8
Weight-bearing activity: Kohrt Wendy, Bloomfield Susan, Little Kathleen, Nelson Miriam E, Yingling, Vanessa R. Physical Activity and Bone Health. Strength training: Medicine & Science in Sports & Exercise November 2004;36(11):1985-1996
Don’t need as much calcium: Prentice Ann, Laskey Ann, Shaw Jacquie, Hudson Geoffrey, Day Kenneth, Jarjou Landing, Dibba Bakary, Paul Alison A. The calcium and phosphorus intakes of rural Gambian women during pregnancy and lactation. Brit J Nutr 1993;(69)885-896
De Souza Genaro P, Martini LA. Effect of Protein Intake on Bone and Muscle Mass in the Elderly. Nutr Rev 2010;68(10):616–623
Sellers EAC, Sharma A, Rodd C. Adaptation of Inuit Children to a Low-Calcium Diet. Can Pub Health J 2003;168(9):1141–1143