Tier 2 — strong

The Influence of Specific Bioactive Collagen Peptides on Body Composition and Muscle Strength in Middle-Aged, Untrained Men: A Randomized Controlled Trial

Denise Zdzieblik, Patrick Jendricke, Steffen Oesser, Albert Gollhofer, Daniel König
International Journal of Environmental Research and Public Health 2021 18(9):4837

Bibliography

PubMed
PMID 33946565
PubMed Central
PMC8125453
DOI
10.3390/ijerph18094837
Funding
The specific collagen peptides (product name BODYBALANCE®) were provided by GELITA GmbH, Eberbach, Germany. This research was in part funded by GELITA GmbH, Eberbach, Germany.
Competing interests
The authors declare no conflict of interest. S.O. has given scientific lectures that were in parts supported by the GELITA AG. He is also coinventor of patents concerning the use of collagen peptides. After the study was finished, D.Z. started as researcher in the Collagen Research Institute, Kiel. Biohack Blueprint assessment: The declaration of "no conflict of interest" is inconsistent with the disclosures immediately following. Oesser is a co-inventor on patents concerning the tested compound and has received manufacturer-supported lecture fees. Zdzieblik moved to a position at the manufacturer-affiliated Collagen Research Institute after the trial. GELITA both funded the study and supplied the product. Substantial industry entanglement.

Study snapshot

DesignMonocentric, prospective, randomised, double-blind, placebo-controlled trial with additional exploratory whey protein arm
ModelOverweight sedentary men aged 30–60 (BMI 27.5–35, body fat >25%), <60 min physical activity per week in prior year
Samplen=120 randomised; n=97 analysed (30 CP, 31 placebo, 36 whey protein per-protocol population); main analysis compared CP vs placebo (n=61)
Intervention15 g/day Bodybalance specific collagen peptides (GELITA AG) versus 15 g/day silicon dioxide placebo versus 15 g/day whey protein isolate (exploratory arm), dissolved in 250 mL water within 1 hour post-training. Combined with supervised 60-minute resistance training three times weekly.
Duration12 weeks
EndpointsPrimary: change in fat free mass (DXA); Secondary: fat mass, body weight, waist circumference; Bilateral isometric leg press strength (Kistler force platform); Estimated skeletal muscle mass by Kim et al. 2002 formula; Safety bloods (creatine kinase, urea); dietary intake records; adverse events

What the study showed, in plain terms

Researchers randomly assigned 120 overweight sedentary men aged 30 to 60 to a 12-week programme of supervised resistance training three times a week, combined with a daily 15 g dose of one of three drinks: a specific collagen peptide (Bodybalance), a silicon dioxide placebo, or whey protein. All three groups did the same training. Body composition was measured by full-body DXA scan before and after; leg strength was measured on an instrumented leg press.

All three groups improved. The training worked for everyone. But the collagen group gained about 1.6 kg more fat-free mass than the placebo group and lost about 1.9 kg more fat mass — differences that were statistically significant in the reported analysis. Muscle strength improved in all groups; the collagen group's gain was larger than placebo but did not reach statistical significance. The exploratory whey arm did not show a statistically significant difference versus collagen, but the 15 g whey dose and post-hoc nature of the comparison make it unsuitable for claiming equivalence or superiority.

The finding is notable because collagen has very little of the amino acid leucine, which is usually considered the key trigger for muscle protein synthesis. The trial does not establish that collagen is equivalent to whey. Direct muscle-protein-synthesis studies favor complete proteins, and this study's exploratory 15 g whey comparison was not designed to settle relative anabolic efficacy.

Key findings

  • Fat free mass gain in CP group was 3.42 ± 2.54 kg versus 1.83 ± 2.09 kg in placebo — significantly higher for CP (p=0.010, Cohen's d = 0.676, medium-to-large effect).
  • Fat mass loss in CP group was 5.28 ± 3.19 kg versus 3.39 ± 3.13 kg in placebo — significantly greater loss for CP (p=0.023, d = 0.579).
  • Estimated skeletal muscle mass gain: 1.23 ± 1.25 kg (CP) vs 0.514 ± 1.05 kg (placebo), p=0.011, d = 0.621.
  • Isometric leg press strength increased by ~163 N in CP versus ~100 N in placebo — direction favouring CP but not statistically significant (p=0.158, d = 0.366).
  • Waist circumference decreased 3.41 ± 2.22 cm in CP versus 2.50 ± 4.19 cm in placebo — direction favouring CP, not significant (p=0.292).
  • Exploratory whey protein arm: fat free mass gain 2.27 ± 2.56 kg, fat mass loss 4.08 ± 2.80 kg — no significant difference versus CP (fat free mass p=0.074) or versus placebo (p=0.442) in post-hoc analysis.
  • Bone mineral content increased significantly in all three groups (~2–4%), attributable to the resistance training rather than supplementation.
  • No adverse events; no pathological findings on creatine kinase or urea safety bloods.

What this study can and cannot tell us

  • The whey protein comparison should be read as exploratory only. The 15 g dose used is below the current ISSN recommendation (20 g / 0.25 g/kg) for post-exercise whey and may have underestimated whey's true effect. This is a design flaw the authors themselves acknowledge.
  • Unequal group sizes after per-protocol exclusion (CP n=30, placebo n=31, whey n=36) reduce statistical power for some between-group comparisons, particularly whey vs the others.
  • Fat-free mass and skeletal muscle mass are estimated via DXA and a published prediction equation (Kim 2002), not directly measured by MRI or muscle biopsy. Some of the observed fat-free mass gain may reflect intramuscular connective tissue rather than contractile muscle protein.
  • Waist circumference was significantly higher at baseline in CP than placebo (p=0.011), indicating a baseline imbalance despite randomisation.
  • Nutrition compliance relied on self-reported 3-day dietary records, which are known to under-report intake. Reported energy intake in placebo (~2400 kcal) is implausibly low for overweight men and suggests systematic under-reporting.
  • Single-sex (male), single-country (Germany), overweight-sedentary population. Generalisability to women, athletes, older adults, and lean populations is unproven.
  • 12-week duration cannot address durability or whether continued supplementation produces further gains.
  • Substantial industry involvement: GELITA funded the trial, supplied the product, and multiple authors have direct commercial or IP ties. The formal COI declaration is inconsistent with the disclosures made.
  • Findings apply specifically to the Bodybalance hydrolysate tested. Other collagen preparations differing in composition or bioavailability may not produce equivalent results.

Related papers in the corpus

Tier 2
Whey protein but not collagen peptides stimulate acute and longer-term muscle protein synthesis with and without resistance exercise in healthy older women: a randomized controlled trial
Sara Y. Oikawa et al. · The American Journal of Clinical Nutrition · 2020

Citation network

Articles citing this research paper

2 articles

Biohack Blueprint analyses that reference this study in their evidence base.

Editorial review

Reviewed by the Biohack Blueprint research team

Last verified

Dr. Khaled Mahmoud, MBBChCritical Care Medicine, Longevity Science & Editorial Direction Dr. Amr Yasser, PhDCardiometabolic, Musculoskeletal, Gut & Bioavailability Dr. Abdulla Mostafa, PhDCellular Senescence, Neurological, Mitochondrial & Brain-Ageing Biology