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The Influence of Specific Bioactive Collagen Peptides on Knee Joint Discomfort in Young Physically Active Adults: A Randomized Controlled Trial

Denise Zdzieblik, Judith Brame, Steffen Oesser, Albert Gollhofer, Daniel König
Nutrients 2021 13(2):523

Bibliography

PubMed
PMID 33562729
PubMed Central
PMC7915677
DOI
10.3390/nu13020523
Funding
The specific collagen peptides (product name FORTIGEL®) 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 GELITA AG. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results. The authors responsible for data assessment and analysis have neither financial nor competing interests concerning the outcome of this investigation. After the study was finished, D.Z. started as a researcher at the Collagen Research Institute, Kiel.

Study snapshot

DesignSingle-centre, prospective, randomised, double-blind, placebo-controlled trial
ModelHealthy, physically active (>3 hours/week of sport) men and women aged 18–30 years with activity-related functional knee joint pain (≥20 mm VAS) but no diagnosed joint disease
Samplen=218 randomised; n=180 completed per-protocol analysis (collagen peptide group n=98; placebo group n=82)
InterventionSpecific collagen peptides (FORTIGEL®, derived from type I collagen, mean molecular weight ~3 kDa), 5 g/day, vs placebo (maltodextrin), for 12 weeks
Duration12 weeks
EndpointsChange in exercise-induced knee pain, participant-assessed (Visual Analog Scale) — co-primary; Change in exercise-induced knee pain, physician-assessed — co-primary; Pain during 20 squats and pain at rest — secondary; Knee joint mobility (flexion/extension) — secondary; Use of alternative therapies (ointments, physiotherapy, etc.) — secondary

What the study showed, in plain terms

This trial set out to confirm, in a larger and broader group, an earlier finding that 5 g/day of a specific collagen peptide reduces activity-related knee pain in young active adults with no diagnosed joint disease.

Over 12 weeks, both the participants themselves and an independent examining physician recorded significantly greater reductions in exercise-induced knee pain with collagen peptides than with placebo — a 42% pain reduction versus 27–28% with placebo by the physician's more objective assessment.

Pain at rest, pain after squats, and knee joint mobility did not differ significantly between groups, largely because relatively few participants had meaningful symptoms in those categories at baseline. The effect size was described by the authors as consistent with, and confirmatory of, an earlier smaller trial in a similar population.

Key findings

  • Physician-assessed exercise-induced knee pain fell significantly more with collagen peptides than placebo (−23.0 ± 19.2 mm vs −14.6 ± 17.9 mm VAS; p=0.003).
  • Participant-assessed exercise-induced knee pain also fell significantly more with collagen peptides than placebo (−21.9 ± 18.3 mm vs −15.6 ± 18.5 mm VAS; p=0.024).
  • Relative pain reduction was 42% with collagen peptides vs approximately 27–28% with placebo by both subject and physician assessment (medium effect sizes, d=−0.34 to −0.45).
  • Pain at rest and pain after 20 squats improved in both groups with no statistically significant between-group difference, largely because few participants (38% and roughly half, respectively) reported meaningful pain under these conditions at baseline.
  • Knee joint mobility (flexion/extension) did not change significantly in either group, consistent with clinically unremarkable baseline mobility values.
  • The need for additional treatments (ointments, bandages, physiotherapy) was significantly reduced by the end of the study in both groups, with no significant between-group difference.

What this study can and cannot tell us

  • Product was supplied and the study was in part funded by GELITA GmbH, the manufacturer of the tested collagen peptide; one author has received GELITA-supported lecture fees and another later joined a GELITA-linked research institute.
  • Both groups improved meaningfully, including placebo, suggesting some of the overall change may reflect altered perception of symptoms rather than a purely pharmacological effect — though the more objective physician assessment still favoured collagen peptides.
  • Pain at rest, pain after squats, and knee mobility outcomes were underpowered because relatively few participants had baseline symptoms in these categories.
  • As with other trials in this series, findings are specific to the tested product (FORTIGEL®, ~3 kDa) and the authors caution results should not be assumed to transfer to other collagen peptide formulations.

Related papers in the corpus

Tier 2
Improvement of Activity-Related Knee Joint Discomfort Following Supplementation of Specific Collagen Peptides
Denise Zdzieblik et al. · Applied Physiology, Nutrition, and Metabolism · 2017
Tier 1
Impact of Specific Bioactive Collagen Peptides on Joint Discomforts in the Lower Extremity during Daily Activities: A Randomized Controlled Trial
Claas Schulze et al. · International Journal of Environmental Research and Public Health · 2024

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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