Clinical trial Recruiting at 2 sites Interventional Ages 60 to 80

Comparing the effects of a vegan diet to an omnivorous diet before knee surgery

Official title: The Effect of a 2-week Preoperative Vegan Diet Versus Omnivorous Diet on the Protein Turnover in the Osteoarthritic Knee

Run by Wageningen University · NCT06130956 · Data updated 2026-11-12

This study is testing whether a vegan diet for two weeks before knee surgery can help older adults with knee osteoarthritis build protein in their muscles and tissues better than a regular diet with meat.

More Osteo Arthritis Knee trials

Quick facts

Study typeInterventional
Ages60 Years to 80 Years
SexAll
Enrollment40 (estimated)
SponsorWageningen University
Academic / other
Drugs / interventionschemotherapy
Locations2 sites (Arnhem and 1 other locations)
StatusRecruiting
StartedOctober 22, 2024
Main results expectedDecember 2026
Study endsDecember 2026
Registry record updatedApril 1, 2025
Trial IDNCT06130956 on ClinicalTrials.gov

Is this trial a fit for you?

Likely a good fit

Ideal candidates are older adults aged 60 to 80 years with a BMI between 20-32, scheduled for total knee arthroplasty.

Probably not a fit

Patients who have followed a vegetarian or vegan diet in the past six months or have certain chronic conditions may not benefit from this study.

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This study investigates the impact of a 2-week preoperative vegan diet versus an omnivorous diet on protein synthesis rates in various musculoskeletal tissues in older adults with knee osteoarthritis who are scheduled for total knee arthroplasty. The primary objective is to assess how these dietary approaches influence protein turnover in tissues such as Hoffa's fat pad, synovium, tendon, bone, ligaments, menisci, and cartilage. The study aims to provide insights into whether a vegan diet can enhance protein synthesis in these tissues compared to a traditional omnivorous diet.

Why it matters

Potential benefit: If successful, this study could provide evidence that a vegan diet may improve recovery outcomes for patients undergoing knee surgery.

How similar studies have gone: While studies on single plant-based foods exist, this approach of a comprehensive vegan diet in older adults is relatively novel and has not been extensively tested.

Who can join: the full rules

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Written informed consent;
* Patients scheduled for total knee arthroplasty;
* BMI between 20-32 kg/m2;
* Aged 60 - 80 years;
* Mentally competent, as judged by the treating physician;

Exclusion Criteria:

* Following a vegetarian or vegan diet or a diet that affects protein intake during the six months prior to the study;
* Participating in a structured progressive exercise training program in the past three months;
* Lost more than 4 kg body weight during three months prior to the study;
* Chronic use of medications that affect protein metabolism (i.e. systemic corticosteroids, or prescription strength acne medications);
* Being diagnosed with one of the following: diabetes mellitus, rheumatoid arthritis, peripheral artery disease Fontaine III or IV, COPD GOLD III or IV, neoadjuvant chemotherapy or radiotherapy, phenylketonuria, collagen disorders (e.g. Marfan and Ehler-Danlos);
* Alcohol abuse;
* Surgical intervention to the knee in the past four weeks;
* Total parenteral nutrition at day of surgery;
* Glomerular filtration rate (GFR) \<20 mL/min/1.73 m2;
* Allergic or intolerant to any product included in the diets;
* Osteoarthritis of the knee secondary to septic arthritis, osteonecrosis, fracture, osteochondritis dissecans, or malignant processes;
* Any other medical condition that may interfere with the safety of the participants or the outcome parameters, in the investigators judgement;
* Not willing to stop nutritional supplements, with the exception of vitamin D and supplements on medical advice.
* Investigator's uncertainty about the willingness or ability of the participant to comply with the protocol instructions;
* Participation in other studies that may have an impact on the outcomes during the three months before the start of the current study.

Where it's running

  • Rijnstate Hospital
    Arnhem, Netherlands
    Recruiting
  • Hospital Gelderse Vallei
    Ede, Netherlands
    Recruiting

Study contacts

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How to take part

  1. Review the eligibility criteria above with your treating physician.
  2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
  3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.
Last reviewed 2026-11-14 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.