Bone Health: Busting Milky Myths
Calcium and milk appear counterproductive, so what really keeps bones healthy?
Calcium and milk appear counterproductive, so what really keeps bones healthy?
The bony human skeleton is more than a Halloween décor mainstay.
Among their many roles, bones support and protect us, provide mobility, and store essential minerals.
Genes do play a significant role in determining bone health, but controllable lifestyle choices can strengthen and protect our skeletons as we age.
Unfortunately, persistent myths about the role of calcium and dairy foods overshadow the reality that there's much more to bone health.
Bones comprise living, growing tissue.
They're really an especially hard kind of connective tissue, made up of collagen, minerals, and cells that build or break down bone.
During our childhood, 20s, and 30s, we create new bone faster than we break down old bone – thus, bone mass increases.
But after around age 30, bone breakdown exceeds formation, raising the risk for bone fractures.
And the term "osteoporosis" simply describes the fragile condition that occurs when you lose too much bone, make too little, or both.
The more bone a person has when they reach peak bone mass, the less likely they are to suffer from osteoporosis.
We've compiled a list of the top 10 ways to protect and enhance your bone health ... lifelong.
#1 - Get moving and lifting
Weight-bearing exercise, which forces the body to work against gravity, is great for bone health.
Weight training, hiking, running, team sports (such as tennis and soccer), jumping rope, and dancing all fall in this category because they put more (good) stress on bones.
Lower-impact options include stair machines, walking, elliptical training, and low-impact aerobics.
Practicing yoga for just a few minutes a day may help build bone strength, too … see Yoga: A Flexible Path to Stronger Bones?.
As explained in that article, certain yoga poses – as well as certain other exercises – can raise the risk of broken bones for people with osteoporosis.
If you have osteoporosis or suspect you may have it, check with your doctor to see which forms of exercise are safe for you.
#2 – Calcium: Exaggerated but essential
Calcium is critically important for bone growth and strength.
But the value of high calcium intakes – and high-dose calcium supplements – is usually overstated.
U.S. guidelines continue to recommend that adult women get 1,000 to 1,200 milligrams of calcium a day, which prompts many to take high-dose calcium pills.
The National Osteoporosis Foundation admits that the positive effects of high calcium intake really only apply to late childhood and early teen years … a critical period for bone building (Weaver CM et al. 2016).
And a recent evidence review found almost no evidence of benefit to adults from calcium supplements … but significantly higher risk of heart attacks, kidney stones, and gastrointestinal problems.
As the authors wrote, "… calcium supplements appear to have a negative risk-benefit effect, and so should not be used routinely in the prevention or treatment of osteoporosis.” (Reid IR et al. 2015)
Walter Willett, M.D. – chair of the Department of Nutrition at the Harvard School of Public Health – agrees that the recommended calcium intakes are unnecessary and could cause problems:
"Essentially, I think that adults do not need 1,200 mg of calcium a day. The World Health Organization's recommendation of 500 mg is probably about right.”
Milk and milk products typically contain high levels of calcium, but not all calcium-rich foods come from the dairy category.
Other food sources include – listed in rough order of calcium content per ounce – cooking greens (e.g., collards, spinach, chard, kale), canned sardines and salmon (with bones), broccoli, black-eyed peas, bok choy, okra, and almonds.
It's pretty clear that a well-rounded diet rich in whole foods – with just a little supplemental calcium as insurance – will do the job.
#3 - Vitamin D: Also exaggerated but vital
Vitamin D helps bones absorb and use calcium.
If you don't make or consume enough of it, you may lose bone, suffer lower bone density, and raise your risk of breakage.
That said, the available evidence doesn't clearly show that vitamin D supplements benefit bone health (Reid IR et al. 2014).
There are four ways to get vitamin D: from sunlight, fatty fish, supplements, and foods fortified with added vitamin D.
The only whole foods that provide large amounts of vitamin D are fatty fish … especially wild-caught tuna, salmon, mackerel, and sardines.
The highest levels of vitamin D – very high indeed – are found in wild Pacific salmon (especially sockeye) and albacore tuna.
Foods commonly fortified with vitamin D include milk, orange juice, soymilk, and cereals.
However, to get even modest amounts of vitamin D from these fortified foods you'd also be consuming a lot of calories, sugars, and/or starches.
#4 - Fruits and vegetables: Unexpected allies
We know, we know … it seems like fruits and vegetables are recommended for everything to do with health.
But large population studies provide pretty good evidence that diets high in fruits and vegetables promote stronger bones (Tucker KL et al. 1999).
It's believed that this is because diets rich in fruits and vegetables produce a more alkaline environment in the body.
#5 - Overlooked minerals and vitamins
Because of the focus on calcium and vitamin D, other key players in bone health get overlooked … and most people probably don't get enough of them.
We're talking about vitamin K2, magnesium, potassium, and boron.
Typical multivitamin supplements contain enough boron to meet your needs.
But most people would benefit from consuming more vitamin K2, potassium, and magnesium.
It's easy to find potassium and magnesium supplements, and they're pretty inexpensive.
Bananas are a famously rich source of potassium; cocoa, dark, leafy greens, and certain fish are good sources of magnesium (see Magnesium, the Miracle Mineral).
Vitamin K2 is concentrated in cheese, egg yolk, butter (especially from grass fed cows), chicken liver, chicken breast, and ground beef (especially grass fed beef).
Some of the highest K2 levels occur in natto … a fermented Japanese soy food that some people love but many Westerners find nasty.
#6 - Omega-3s: Fish for bones
Research suggests diets rich in omega-3 fatty acids lead to healthier, stronger bones.
Fatty fish are the best food sources by far, and they provide the "long-chain” omega-3s our bodies actually need.
The "short-chain” omega-3 fat found in some plant foods (ALA) is far less beneficial because the body has to convert it (very inefficiently) into the long-chain "seafood” forms (DHA and EPA) critical to brain, eye, and immune health.
The only good plant sources of the less beneficial short-chain omega-3s are canola oil, flax seeds and oil, hemp seeds, chia seeds, dark-green leafy vegetables, and walnuts.
In addition to ensuring adequate omega-3 fat intake – at least 250 mg daily – it's important to limit your intake of omega-6 fats.
The omega-6s that abound in cheap vegetable oils (soy, corn, safflower, sunflower, cottonseed) weaken bone when consumed in the grossly excessive amounts typical of the standard American diet … see Omega-3 Fats Built Rats' Bones: Omega-6s Weakened Them.
#7 - Don't smoke, or drink in excess
Smoking cigarettes and consuming excessive amounts of alcohol has been associated with loss of bone mineral density.
#8 - Avoid excessive weight loss
People who are underweight have an increased risk of fracture and bone loss.
Extreme weight loss, including after weight loss surgery, may also lead to bone loss.
#9 - Pay attention to medications and conditions
Weight loss and certain medical conditions (or the medications used to treat them), can hurt bone health.
These include celiac disease, pulmonary disease, Cushing's syndrome, depression, diabetes, early menopause, hyperthyroidism, IBS, Lupus, MS, Parkinson's disease, and rheumatoid arthritis.
#10 - Test your bone health
Consider scheduling a bone mineral test if you are a woman aged 65 or older or a man aged 70 or older.
Earlier testing is wise for people with certain diseases, and for people who take medications known to increase risk.
- Bolland MJ, Leung W, Tai V, Bastin S, Gamble GD, Grey A, Reid IR. Calcium intake and risk of fracture: systematic review. BMJ. 2015 Sep 29;351:h4580. doi: 10.1136/bmj.h4580. Review.
- Calcium Sources in Food. Harvard T.H. Chan School of Public Health. Accessed at http://www.hsph.harvard.edu/nutritionsource/calcium-sources/
- Emaus N, Gjesdal CG, Almås B, Christensen M, Grimsgaard AS, Berntsen GK, Salomonsen L, Fønnebø V. Vitamin K2 supplementation does not influence bone loss in early menopausal women: a randomised double-blind placebo-controlled trial. Osteoporos Int. 2010 Oct;21(10):1731-40. doi: 10.1007/s00198-009-1126-4. Epub 2009 Nov 25.
- Knapen MH, Drummen NE, Smit E, Vermeer C, Theuwissen E. Three-year low-dose menaquinone-7 supplementation helps decrease bone loss in healthy postmenopausal women. Osteoporos Int. 2013 Sep;24(9):2499-507. doi: 10.1007/s00198-013-2325-6. Epub 2013 Mar 23.
- Knapen MH, Schurgers LJ, Vermeer C. Vitamin K2 supplementation improves hip bone geometry and bone strength indices in postmenopausal women. Osteoporos Int. 2007 Jul;18(7):963-72. Epub 2007 Feb 8.
- Koitaya N, Sekiguchi M, Tousen Y, Nishide Y, Morita A, Yamauchi J, Gando Y, Miyachi M, Aoki M, Komatsu M, Watanabe F, Morishita K, Ishimi Y. Low-dose vitamin K2 (MK-4) supplementation for 12 months improves bone metabolism and prevents forearm bone loss in postmenopausal Japanese women. J Bone Miner Metab. 2014 Mar;32(2):142-50. doi: 10.1007/s00774-013-0472-7. Epub 2013 May 24.
- Orchard TS, Pan X, Cheek F, Ing SW, Jackson RD. A systematic review of omega-3 fatty acids and osteoporosis. Br J Nutr. 2012 Jun;107 Suppl Fact2:S253-60. Doi: 10.1017/S0007114512001638. Review.
- Reid IR, Bolland MJ, Grey A. Effects of vitamin D supplements on bone mineral density: a systematic review and meta-analysis. Lancet. 2014 Jan 11;383(9912):146-55. doi: 10.1016/S0140-6736(13)61647-5. Epub 2013 Oct 11. Review.
- Reid IR, Bristow SM, Bolland MJ. Calcium supplements: benefits and risks. J Intern Med. 2015 Oct;278(4):354-68. doi: 10.1111/joim.12394. Epub 2015 Jul 14. Review.
- Tai V, Leung W, Grey A, Reid IR, Bolland MJ. Calcium intake and bone mineral density: systematic review and meta-analysis. BMJ. 2015 Sep 29;351:h4183. doi: 10.1136/bmj.h4183. Review.
- Tucker KL, Hannan MT, Chen H, Cupples LA, Wilson PW, Kiel DP. Potassium, magnesium, and fruit and vegetable intakes are associated with greater bone mineral density in elderly men and women. Am J Clin Nutr. 1999 Apr;69(4):727-36.
- Weaver CM, Gordon CM, Janz KF, Kalkwarf HJ, Lappe JM, Lewis R, O'Karma M, Wallace TC, Zemel BS. The National Osteoporosis Foundation's position statement on peak bone mass development and lifestyle factors: a systematic review and implementation recommendations. Osteoporos Int. 2016 Feb 8. [Epub ahead of print]