Bone mass decreases markedly with aging, compromising overall fitness and contributing to fractures and falls, especially among older adults living in residential care. Evidence indicates that nutritional factors play critical roles in maintaining bone mass and overall health. Findings from a recent study suggest that dietary protein and calcium reduce the risk of fractures and falls in older adults.

Calcium participates in many aspects of human health, but it is perhaps best known for its role in bone health. The body maintains very tight control over the calcium circulating in the blood at any given time – a phenomenon referred to as calcium balance. Protein exerts variable effects (both good and bad) on a person’s calcium balance, depending on their dietary calcium intake. For example, dietary protein promotes the production of insulin-like growth factor-1, a protein involved in bone formation. But protein also increases urinary calcium losses, which can harm bone health. Current dietary guidelines recommend that older adults consume 1,200 milligrams (mg) of calcium per day and 0.8 grams of protein per kilogram (g/kg) of bodyweight per day.

The two-year, randomized-controlled trial involved more than 7,000 adults (average age, 86 years) living in 60 residential aged care facilities in Australia. All participants were vitamin D-sufficent. Half of the facilities supplemented the residents' diet with additional calcium- and protein-rich foods (milk, yogurt, and cheese) to achieve a total intake of 1,142 mg of calcium and 69 grams of protein (1.1 g/kg body weight) per day. The other half of the facilities maintained their usual menus, which provided residents 700 mg/day of calcium and 58 grams (0.9 g/kg body weight) of protein per day. The investigators tracked the number of falls, fractures, and deaths from all causes among the participants.

They found that residents who consumed the high calcium, high protein foods were 33 percent less likely to experience any type of fracture, 46 percent less likely to experience a hip fracture, and 11 percent less likely to experience a fall. These results were achieved within five months of initiating the dietary changes. No changes in the number of deaths were observed.

These findings suggest that increasing calcium and protein intake reduces the risk of falls and fractures among older adults in residential care. It is noteworthy that the foods used in this intervention were dairy products. More than two-thirds of people worldwide cannot tolerate dairy products due to lactose intolerance. Non-dairy sources of calcium- and protein-rich foods include canned, whole sardines; fortified nut milks and cereals; and beans, especially soybeans and soy products, such as tofu. This study was funded by various international dairy councils.

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