HealthEffectsofIncreasingProteinIntakeAbove theCurrentPopulationReferenceIntakeinOlder Adults:ASystematicReviewoftheHealthCouncil oftheNetherlands

Abstract

Whetherolderadultsneedmoreproteinthanyoungeradultsisdebated.ThepopulationreferenceintakeforadultssetbytheEuropeanFoodSafety Authorityis0.83g/kgbodyweight(BW)/dbasedprimarilyonnitrogenbalancestudies,buttheunderlyingdataonhealthoutcomesareoutdated. AnexpertcommitteeoftheHealthCounciloftheNetherlandsconductedasystematicreview(SR)ofrandomizedcontrolledtrials(RCTs)examining theeffectofincreasedproteinintakeonhealthoutcomesinolderadultsfromthegeneralpopulationwithanaveragehabitualproteinintake≥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 musclestrength,thisappliedto3of8RCTsinthecontextofphysicalexerciseandin1of7RCTswithoutphysicalexercise.Fortheotheroutcomes, <30% (0–29%) of RCTs showed a statistically significant effect. The committee concluded that increased protein intake has a possible beneficial effect onleanbodymassand,whencombinedwithphysicalexercise,musclestrength;likelynoeffect onmusclestrengthwhennotcombinedwith physical exercise, or on physical performance and bone health; an ambiguouseffect on serum lipids; and that toofewRCTswereavailable to allow forconclusionsontheotheroutcomes.ThisSRprovidesinsufficientlyconvincingdatathat increasingproteininolder adultswithaproteinintake ≥0.8g/(kgBW·d)elicitshealthbenefits. AdvNutr2022;13:1083–1117