I’ve long been concerned about people taking isolated calcium supplements, purely in the hope that by doing so, they will reduce the likelihood of fractures later in life. My fears now seem to have been confirmed by recent research that has been highlighted in the following article in the Telegraph:
Of course, our bones do contain calcium, but they also contain many other minerals. But even minerals are only one part of the complex jigsaw that determines our bone strength and our potential risk of fractures. Focusing only on calcium (or even calcium together with some of the other minerals we need for bone health) is and has always been, in my opinion, a huge error. In addition to calcium now having been demonstrated to not aid in improving our bone strength or preventing fractures, it has also been highlighted in other studies to spike our incidence of heart attacks, as the Telegraph article quite rightly relates. Interestingly, the formation of atherosclerotic plaque (caused by consuming calcium supplements), which leads on to arterial disease, only seems to occur in the presence of inadequate dietary magnesium (1). This is just one example of why we can’t just focus on one mineral and ignore all the rest.
In my recently published book, Love Your Bones, I highlight several studies indicating the shortcomings of supplementing with calcium, and the fact that this practice is not without its inherent risks. Researchers questioned over 40 years ago why the RDA cited for calcium intake seems to be set so high here in the UK, when studies of Bantu women in South Africa, who have a daily calcium intake of a mere 300mg, show that their osteoporosis incidence is practically zero, even in advanced age (2).
Low calcium diets do not seem to cause problems with bone demineralisation, and one study of Sahara oilfield workers found they were able to excrete 320 mg more calcium than they were consuming, without bone decalcification. Some authors are now even suggesting that we should be treating osteoporotic hip fractures with a low calcium diet, which seems to fly in the face of conventional thinking, and certainly current recommendations.
Bone mineral density (BMD) is the common method by which we currently assess fracture risk, but its accuracy is questionable. There are certain parts of the world in which overall bone mass and BMD are lower than in developed nations, but the fracture rate is also lower. A better predictor of osteoporosis is the dietary ratio of plant protein to animal protein; the more animal protein consumed, the higher the osteoporosis rate. BMD is not significantly associated with this ratio (3).
Contrary to popular belief, and as I discuss in detail in Love Your Bones, dairy products are not a good food for osteoporosis prevention and bone-building. Interestingly, whilst the bones of women in the countries with the highest dairy product consumption may seem, on average, to be denser than those with low dairy consumption, this does not appear to protect them from fractures (4). It is also now being recognised that dairy products are of little value in promoting bone health and strength in children, and a re-evaluation of dietary recommendations was suggested by prominent researchers more than ten years ago (5).
The calcium pill manufacturers and dairy industry have had us in their grip over our food and supplement choices with regard to bone health and osteoporosis prevention for many years. Old habits die hard. Perhaps, at last, people might now start to realise that the old paradigm is as outdated as it is potentially harmful. It’s about time.
- Chakraborti S, Chakraborti T, Mandal M, Mandal A, Das S, Ghosh S. ‘Protective role of magnesium in cardiovascular diseases: a review.’ Molecular and Cellular Biochemistry 2002 Sep;238(1-2):163-79.
- Walker ARP, Walker BF, Richardson BD. ‘Metacarpal bone dimensions in young and aged South African Bantu consuming a diet low in calcium.’ Postgraduate Medical Journal (June 1971) 47, 320-325).
- Sellmeyer DE, Stone KL, Sebastian A, et al. ‘A high ratio of dietary animal to vegetable protein increases the rate of bone loss and the risk of fracture in post-menopausal women.’ American Journal of Clinical Nutrition 73 (2001): 118-122.
- Ho SC. ‘Body measurements, bone mass and fractures: does the East differ from the West?’ Journal of Clinical Orthopaedics and Related Research 323 (1996): 75-80.
- Lanou AJ, Berkow SE, Barnard ND. ‘Calcium, Dairy Products, and Bone Health in Children and Young Adults: A Reevaluation of the Evidence.’ Pediatrics 115 No. 3 March 1, 2005 pp. 736 -743.