Myth busted: Extra milk no guarantee of strong bones
Despite this, the public continues to hear that more calcium is better because “many companies with vested interests” in sales of supplements and dairy products “sponsor influential organizations and academic opinion leaders”, lead researcher Dr. Mark Bolland, associate professor in the School of Medicine at the University of Auckland in New Zealand, said in an e-mail.
As a result, older people had been encouraged to improve bone health by increasing calcium intake through food, study authors said.
The studies find that increasing calcium intake through food or supplements should not be recommended for fracture or osteoporosis prevention.
The experts, from the University of Auckland in New Zealand, wrote: ‘Calcium supplements are commonly taken to achieve such intakes, which are considerably higher than the average intake of calcium in the diet in older people in Western countries. The researchers also looked at 26 randomized controlled trials of calcium supplements, and although the scientists observed a slight reduction in people’s fracture risk with calcium supplements, the researchers cautioned that the evidence was “weak and inconsistent”.
“There is no evidence now that increasing dietary calcium intake prevents fractures”, they said.
In a corresponding editorial, Karl Michaëlsson, a professor at Uppsala University in Sweden, writes that given the lack of evidence to support increasing calcium and vitamin D intake for better bone health, the continued emphasis is “puzzling”.
Dairy products are rich in calcium but so are leafy green vegetables, fortified milks such as soymilk and a few juices and breakfast cereals.
According to the NHS, adults need 700mg of calcium a day.
‘The weight of evidence against such mass medication of older people is now compelling, ‘ he said.
And they warned that calcium supplements have “an unfavourable risk/benefit profile”, meaning they could do more harm than good.
On its website, for instance, Osteoporosis Canada thanks its two corporate partners: the Dairy Farmers of Canada and Caltrate, a maker of calcium and vitamin D supplements.
A 2013 report from the U.S. Preventive Services Task Force demonstrated no evidence that taking the mineral along with vitamin D reduced the risk of fracture in healthy, postmenopausal women.
“Taken together, we think this is the strongest possible evidence that taking calcium supplements will not be beneficial unless there are clear medical reasons that a calcium supplement is needed”, he said.
Considerations included the amount of calcium being consumed from dietary sources, tolerance of the supplement and other health conditions such as cardiovascular risk.
Despite these findings, Americans love their supplements.
“The article flags the need for manufacturers to be required to substantiate their claims to a high level so that consumers are not being misled as to any health claims and by dubious research”. Falling is the biggest risk that leads to fractures, which is why exercise, building muscle strength and keeping mobile play a much greater role in reducing risks, she said.
One review focused on two dietary studies that compared how patients over 50 years of age fared when instructed to consume higher versus lower levels of calcium.
And studies have shown that taking supplements can also cause harm.