Dr. Aaron Carroll: There are few topics that just never get old for me: pay for performance, over-testing, medical myths, and of course my never-ending war with the milk industrial complex. I see you milk emperor, we're coming at you with new data. This is healthcare triage news.   [intro plays]   The milk industrial complex would have you believe that drinking milk or increasing your dietary calcium intake will protect your bones. Two new studies from the BMJ bring evidence to this fight. The first is Calcium Intake and Risk of Fracture: a Systematic Review. This was a systematic review to look at randomized controlled trials or observational studies to see if that's the case, with fractures the endpoint. Participants had to be at least fifty years old. They found only two randomized controlled trials of dietary calcium intake increases with two hundred and sixty-two participants in total, there were however 44 cohort studies, 37 of calcium, 14 of milk, and eight of dairy intake total.   Let's take calcium first. Most studies found no relationship between intake and fracture: 17 of 21 for hip, seven of eight for vertebral, 5 of 7 for forearm, and 14 of 22 for total. For dairy, 11 of 13 found no association and for milk 25 of 28 studies found no association. The milk emperor has no clothes. Let's try calcium supplementation where we're not talking about your diet. There were 26 randomized controlled trials of that. Supplementation did reduce total fracture, with a relative risk of .89, and vertebral fractures a little bit, relative risk of .96, but there was no protection against tip or forearm fractures.   All studies were not a similar quality though. When they considered the four randomized controlled trials at lowest risk of bias, no effective fracture protection was seen at all: in any sites. Similar disappointing results were seen for calcium monotherapy and co-administered calcium and vitamin D. Conclusion: dietary calcium isn't associated with the risk of fracture. There's no evidence that increasing dietary calcium prevents fracture. Even the evidence that says calcium supplementation prevents fracture is weak.   Study two is Calcium Intake in Bone Mineral Density: Systematic Review and Meta-Analysis. Pretty much the same study as the first but with bone density, not fracture as the outcome of interest. In this case though, they stuck to randomized controlled trials. They found fifty nine of them, both for dietary calcium: 15, and calcium supplementation: 51. Increasing dietary calcium intake did increase bone mineral density by 0.6-1%, both at the hip and total body at one year. It also increase bone mineral density there and at the lumbar spine and femoral neck by .7-1.8% at two years. It had no effect on the forearm. Calcium supplementation increased bone mineral density all over by 0.7-1.8% at one, two, and two and a half years.   But these changes, while statistically significant, are unlikely to lead to any meaningful outcomes. They certainly don't protect against fracture: see the first study. From the accompanying editorial entitled Calcium Supplements Do Not Prevent Fractures, by use of guidelines such as those by NOF and the International Osteoporosis Foundation, marketing now extends to all older people with dietary intakes below the recommended 1,200 milligrams of calcium and 800 to 1,000 IU of vitamin D daily. By this definition, virtually the whole population aged over 50 is at risk. Most will not benefit from increasing their intakes and will be exposed instead to a higher risk of adverse events such as constipation, cardiovascular events, kidney stones, or admission for acute gastrointestinal symptoms. The weight of evidence against such mass-medication of older people is now compelling, and it is surely time to reconsider his controversial recommendations. Go tell the milk emperor! Tell him Aaron Carroll sent you.   Health Care triage is supported in part by viewers like you through Patreon.com, a service that allows you to support the show through monthly donation. Your support helps us make this bigger and better. We'd especially like to thank our research associate, Cameron Alexander, and our first ever surgeon admiral thanks Sam. Thanks Cameron! Thanks Sam! More information can be found at Patreon.com/healthcaretriage.