The study, published on the British Medical Journal's website, found that people over the age of 50 don’t get stronger bones by eating calcium-packed dairy products or taking calcium supplements.
In fact, those who took calcium were just as likely to suffer from fractures as those who did not.
Dr Ian Reid from the University of Auckland in New Zealand told DairyReporter that the focus on treating bone diseases, such as osteoporosis, needs to be elsewhere.
“I think we’ve actually misdirected a whole lot of effort into the use of calcium supplements, in particular in North America, where use has been higher for last 30 years,” he said.
Following old information
This information flies in the face of long-held beliefs that calcium makes for stronger, better bones.
For years, US guidelines have advised men and women to take anywhere from 1,000 to 1,200 mg of calcium per day to help prevent fractures and improve bone density.
Reid said this likely lasted for so long due to an overreliance on studies from the 1970s and 1980s.
Now, there are more sophisticated bone density studies, and none have shown the need for anything more than 500mg of calcium per day for bone density health.
Going a step further, the study said too much calcium may cause build ups in the arteries or in the kidneys, which can cause ailments such as heart disease or kidney stones respectively.
"Dietary calcium intake is not associated with risk of fracture, and there is no clinical trial evidence that increasing calcium intake from dietary sources prevents fractures," the study said.
"Evidence that calcium supplements prevent fractures is weak and inconsistent."
Methodology of the study
The researchers looked at two studies, finding in one that increasing calcium intake from supplements increases bone density by 1% to 2%, something they said is unlikely to create a meaningful reduction in the risk of fracture.
“This is not a cumulative benefit,” Reid said. “It’s only 1% at any year. It’s a one off small gain. When you look at the fracture data in the large high quality studies carried out in the last 10 to 15 years, we found there is no total benefit to total number of fractures. There may even be an increase. I think we should really be deleting calcium as a significant tissue in management of osteoporosis.”
In another study, researchers found that dietary calcium is not associated with risk of fracture, with no clinical evidence finding that increase in consumption helps prevent fractures.
Professor Karl Michaëlsson from Uppsala University in Sweden wrote in an accompanying commentary with the study that the although recommendations point to those over 50 taking calcium, most will not benefit by increasing their intakes.
“The weight of evidence against such mass medication of older people is now compelling, and it is surely time to reconsider these controversial recommendations,” he wrote.
While dairy may be useful to help the elderly keep weight on their body as they get older, Reid said he sees no benefit in calcium supplements for bone health.
In fact, he sees the risk of kidney stones and abdominal problems as being greater than the reward.
“I don’t think people should be using calcium supplements at all,” Reid said. “They’ve been so entrenched and supported by industry for so long that it’s taking a while to turn around. However, calcium supplement use has declined by 30% in the last few years [in the US]. I hope that will continue and accelerate.”
Source: British Medical Journal http://dx.doi.org/10.1136/bmj.h4183
Calcium intake and bone mineral density: systematic review and meta-analysis
Authors V. Tai, W. Leung, A. Grey, I. Reid, M. Bolland