Whether older adults need more
protein than younger adults is debated. The population reference intake for adults set by the European Food Safety Authority is 0.83 g/kg
body weight (BW)/d based primarily on
nitrogen balance studies, but the underlying data on health outcomes are outdated. An expert committee of the Health Council of the Netherlands conducted a systematic review (SR) of randomized controlled trials (RCTs) examining the effect of increased
protein intake on health outcomes in older adults from the general population with an average habitual
protein intake ≥0.8 g/(kg BW · d). Exposures were the following: 1) extra
protein compared with no
protein and 2) extra
protein and physical exercise compared with physical exercise. Outcomes included lean body mass, muscle strength, physical performance, bone health, blood pressure, serum
glucose and
insulin, serum
lipids, kidney function, and cognition. Data of >1300 subjects from 18 RCTs were used. Risk of bias was judged as high (n = 9) or "some concerns" (n = 9). In 7 of 18 RCTs, increased
protein intake beneficially affected ≥1 of the tested outcome measures of lean body mass. For muscle strength, this applied to 3 of 8 RCTs in the context of physical exercise and in 1 of 7 RCTs without physical exercise. For the other outcomes, <30% (0-29%) of RCTs showed a statistically significant effect. The committee concluded that increased
protein intake has a possible beneficial effect on lean body mass and, when combined with physical exercise, muscle strength; likely no effect on muscle strength when not combined with physical exercise, or on physical performance and bone health; an ambiguous effect on serum
lipids; and that too few RCTs were available to allow for conclusions on the other outcomes. This SR provides insufficiently convincing data that increasing
protein in older adults with a
protein intake ≥0.8 g/(kg BW · d) elicits health benefits.