Evidence map›Paper›PMID 33871558›Full record

Trial reportThe American journal of clinical nutrition2021

Does supplementation with leucine-enriched protein alone and in combination with fish-oil-derived n-3 PUFA affect muscle mass, strength, physical performance, and muscle protein synthesis in well-nourished older adults? A randomized, double-blind, placebo-controlled trial.

Caoileann H Murphy, Ellen M Flanagan, Giuseppe De Vito, Davide Susta, Kathleen A J Mitchelson, Elena de Marco Castro, Joan M G Senden, Joy P B Goessens, Agnieszka Mikłosz, Adrian Chabowski and 6 more

Registry-linked trialOpen access · bronzeAbstract readRandomized Controlled Trial
PubMed Full text at PMC Publisher
In one paragraph

Trial report in The American journal of clinical nutrition, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT03429491 (Novel Nutrition Solutions in Elderly at Risk of Sarcopenia), which is not on this map. Cited by 27 papers, 6 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
27citing papers in PubMed, 6 pooled it
3.3field-weighted citation impact, top 7% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

NCT03429491 nacompletednot on this map

Novel Nutrition Solutions in Elderly at Risk of Sarcopenia: LC n-3 PUFA and Leucine Combinations

TypeinterventionalSponsorUniversity College DublinRan2017 to 2018Enrolled108ConditionsSarcopeniaArmsPlacebo, Leucine-enriched protein, LC n-3 PUFA
3 · Its place in the literature

Who cites it

27 citing papers in PubMed, 6 syntheses or guidelines pooled it, 44 citations in OpenAlex.

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  11. Nutrients · 2026
    Review
  12. The Role of Omega-3 Polyunsaturated Fatty Acids on Sarcopenia and Aging Muscle.International journal of environmental research and public health · 2026
    Review
  13. Article
  14. Article
  15. Article
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  18. Nutrition and exercise for sarcopenia treatment.Osteoporosis and sarcopenia · 2025
    Review
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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

16 authors at 6 institutions in 6 countries.

Caoileann H MurphySchool of Public Health, Physiotherapy and Sport Science, University College Dublin, Dublin, Ireland.ORCID 0000-0001-5967-3419
Ellen M FlanaganSchool of Public Health, Physiotherapy and Sport Science, University College Dublin, Dublin, Ireland.
Giuseppe De VitoSchool of Public Health, Physiotherapy and Sport Science, University College Dublin, Dublin, Ireland.
Davide SustaSchool of Health and Human Performance, Dublin City University, Dublin, Ireland.
Kathleen A J MitchelsonSchool of Public Health, Physiotherapy and Sport Science, University College Dublin, Dublin, Ireland.
Elena de Marco CastroSchool of Public Health, Physiotherapy and Sport Science, University College Dublin, Dublin, Ireland.
Joan M G SendenDepartment of Human Movement Sciences, Maastricht University, Maastricht, Netherlands.
Joy P B GoessensDepartment of Human Movement Sciences, Maastricht University, Maastricht, Netherlands.
Agnieszka MikłoszDepartment of Physiology, Medical University of Bialystok, Bialystok, Poland.
Adrian ChabowskiDepartment of Physiology, Medical University of Bialystok, Bialystok, Poland.
Ricardo SeguradoSchool of Public Health, Physiotherapy and Sport Science, University College Dublin, Dublin, Ireland.
Clare A CorishSchool of Public Health, Physiotherapy and Sport Science, University College Dublin, Dublin, Ireland.
Sinead N McCarthyTeagasc Food Research Centre, Ashtown, Dublin, Ireland.
Brendan EganSchool of Health and Human Performance, Dublin City University, Dublin, Ireland.
Luc J C van LoonDepartment of Human Movement Sciences, Maastricht University, Maastricht, Netherlands.
Helen M RocheSchool of Public Health, Physiotherapy and Sport Science, University College Dublin, Dublin, Ireland.ORCID 0000-0002-0628-3318
University College Dublin · IEMaastricht University · NLMedical University of Białystok · PLDublin City University · IESechenov University · RUTeagasc - The Irish Agriculture and Food Development Authority · IE

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundLeucine-enriched protein (LEU-PRO) and long-chain (LC) n-3 (ω-3) PUFAs have each been proposed to improve muscle mass and function in older adults, whereas their combination may be more effective than either alone.

objectiveThe impact of LEU-PRO supplementation alone and combined with LC n-3 PUFAs on appendicular lean mass, strength, physical performance and myofibrillar protein synthesis (MyoPS) was investigated in older adults at risk of sarcopenia.

methodsThis 24-wk, 3-arm parallel, randomized, double-blind, placebo-controlled trial was conducted in 107 men and women aged ≥65 y with low muscle mass and/or strength. Twice daily, participants consumed a supplement containing either LEU-PRO (3 g leucine, 10 g protein; n = 38), LEU-PRO plus LC n-3 PUFAs (0.8 g EPA, 1.1 g DHA; LEU-PRO+n-3; n = 38), or an isoenergetic control (CON; n = 31). Appendicular lean mass, handgrip strength, leg strength, physical performance, and circulating metabolic and renal function markers were measured pre-, mid-, and postintervention. Integrated rates of MyoPS were assessed in a subcohort (n = 28).

resultsNeither LEU-PRO nor LEU-PRO+n-3 supplementation affected appendicular lean mass, handgrip strength, knee extension strength, physical performance or MyoPS. However, isometric knee flexion peak torque (treatment effect: -7.1 Nm; 95% CI: -12.5, -1.8 Nm; P < 0.01) was lower postsupplementation in LEU-PRO+n-3 compared with CON. Serum triacylglycerol and total adiponectin concentrations were lower, and HOMA-IR was higher, in LEU-PRO+n-3 compared with CON postsupplementation (all P < 0.05). Estimated glomerular filtration rate was higher and cystatin c was lower in LEU-PRO and LEU-PRO+n-3 postsupplementation compared with CON (all P < 0.05).

conclusionsContrary to our hypothesis, we did not observe a beneficial effect of LEU-PRO supplementation alone or combined with LC n-3 PUFA supplementation on appendicular lean mass, strength, physical performance or MyoPS in older adults at risk of sarcopenia. This trial was registered at clinicaltrials.gov as NCT03429491.

Indexed as

Physical Functional PerformanceAgedAged, 80 and overAgingBiomarkersBody CompositionDouble-Blind MethodFatty Acids, Omega-3FemaleGene Expression RegulationHumansMaleMuscle ProteinsMuscle, SkeletalMuscle StrengthNutritional StatusBiomarkersFatty Acids, Omega-3Muscle ProteinsagingLC n–3 PUFAleucinemuscle massproteinsarcopeniastrength

Identifiers

PMID33871558
PMCPMC8168361
OpenAlexW3152498372

What OpenQuestion holds

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LicenceCC BY-NC
Read underepoch 390

Registered trials

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.