부산대학교 도서관

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g/kg body weight (BW)/d based primarily on nitrogen balance studies, but the underlying data on health outcomes are outdated.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 effecton lean body mass and, when combined with physical exercise, muscle strength; likely no effecton muscle strength when not combined with physical exercise, or on physical performance and bone health; an ambiguous effecton serum lipids; and that too few RCTs were availableto 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.Statement of Significance: This systematic review provides a comprehensive, transparent, and up-to-date overview of randomized controlled trials that explicitly focus on potential health effects of protein intakes above the nitrogen-balance studies-based population reference intake of 0.8 g/(kg BW · d) in older adults from the general population. This review also serves as an additional source of evidence for deriving a recommended protein intake for older adults.