Don’t I need dairy for strong healthy bones?

If you have an allergy or intolerance to dairy products, or a personal preference to avoid them, a main concern you or your loved ones might have is – isn’t dairy needed for healthy bones?

A lot of us associate dairy with calcium, and calcium with strong and healthy bones.  Indeed, about 99% of the calcium in our bodies is stored within our bones.  Along with phosphorus, calcium is one of the two most abundant mineralizing nutrients that make bones strong and hard. You might be surprised to know that the link between calcium intake and bone health is not very strong, however.

Looking at just dairy as a factor, you may be interested to know that in countries where there is no milk consumed, there are actually lower rates of fractures (broken bones). A large review study found no association between milk intake and risk of fractures.

Ok, if not just dairy, bone health is dependant on calcium intake then, yes?

Not entirely.  An important systematic review that was released just a few months ago found that increasing calcium in the diet is not associated with a decreased risk of fractures.  The benefit from using calcium supplements was small and inconsistent.  Similarly, another recent systematic review and meta analysis found that increasing calcium intake via diet and supplements is associated with only tiny (and non significant) improvements in bone mineral density.  

This tells us that there is much more to bone health than just the amount of calcium we take in.

Yes, calcium makes up an important part of the bone matrix.  It is one of the nutrients required for creating healthy strong bones.  There is more to the story though.  Adequate protein (which helps to enhance calcium absorption), vitamin D (which helps with calcium absorption and assists with production bone proteins for mineralization) and vitamin K (which assists with mineral deposition) are also very important, as well as avoiding too much sodium in the diet (when calcium intake is low, it can increase urinary calcium loss).  

Outside of nutrition, factors such as thyroid, parathyroid, oestrogen and testosterone hormone levels; medications, such as corticosteroids and  some antidepressants; medical conditions such as untreated coeliac disease, rheumatoid arthritis and kidney disease; and lifestyle factors, such as levels of weight bearing exercise, smoking, weight and excessive alcohol intake can all influence bone health.

So you can see, there is SO much more to bone health than just consuming dairy products.  Although they are a good source of calcium and other nutrients important for bone health, careful nutritional planning (blog on dairy-free calcium sources to come next) and a healthy lifestyle can result in strong, healthy bones for a dairy-avoider.  

References:

Gropper SS, Smith JL. Advanced Nutrition and Human Metabolism. Cengage Learning; 2012. 606 p.

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..

Bolland MJ, Leung W, Tai V, Bastin S, Gamble GD, Grey A, et al. Calcium intake and risk of fracture: systematic review. BMJ. 2015 Sep 29;351:h4580.

Bischoff-Ferrari HA, Dawson-Hughes B, Baron JA, Kanis JA, Orav EJ, Staehelin HB, et al. Milk intake and risk of hip fracture in men and women: a meta-analysis of prospective cohort studies. J Bone Miner Res. 2011 Apr;26(4):833–9.

Michaëlsson K, Wolk A, Langenskiöld S, Basu S, Lemming EW, Melhus H, et al. Milk intake and risk of mortality and fractures in women and men: cohort studies. BMJ. 2014 Oct 28;349:g6015.

Lanou AJ. Should dairy be recommended as part of a healthy vegetarian diet? Counterpoint. Am J Clin Nutr. 2009 May 1;89(5):1638S – 1642S.

Ludwig DS, Willett W. Three daily servings of reduced-fat milk: An evidence-based recommendation? JAMA Pediatr. 2013 Sep 1;167(9):788–9.