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

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

Status
Recruiting
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT06130956
Acronym
KneeT-vegan
Enrollment
40
Registered
2023-11-14
Start date
2024-10-22
Completion date
2026-12-31
Last updated
2025-04-01

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Osteo Arthritis Knee, Protein Synthesis

Brief summary

Rationale: Protein from plant-based foods may be unable to stimulate protein synthesis due to a suboptimal essential amino acid content and a lower digestibility. However, a more optimal amino acid profile may be achieved by increasing portions sizes and blending multiple plant-based sources. Studies investigating the anabolic properties of vegan diets (total elimination of animal-based foods) rather than single plant-based foods in older adults are scarce. It remains unknown if a vegan diet can also affect protein synthesis rates in other musculoskeletal tissues than muscle. Primary objective: To assess the effects of a 2-week preoperative vegan diet in comparison to an omnivorous diet on protein synthesis rates in Hoffa's fat pad, synovium, tendon, bone, ligaments, menisci, and cartilage in older adults with knee osteoarthritis undergoing total knee arthroplasty. Secondary objective: To assess the effects of a 2-week preoperative vegan diet in comparison to an omnivorous diet on blood pressure and plasma amino acids in older adults with knee osteoarthritis undergoing total knee arthroplasty. Study design: Multi-center, randomized, controlled trial with an intervention and a control group. Study population: 40 older adults (60 - 80 years) with osteoarthritis of the knee undergoing total knee replacement. Intervention: Controlled vegan diet versus controlled omnivorous diet, for a duration of 14 days. Main study parameters/endpoints: Primary study parameters are protein synthesis rates of Hoffa's fat pad, synovium, tendon, bone, ligament, menisci, and cartilage. Secondary parameters include blood pressure and plasma amino acids.

Interventions

DIETARY_SUPPLEMENTVegan diet

Vegan diet for 2 weeks before surgery

DIETARY_SUPPLEMENTOmnivorous diet

Omnivorous diet for 2 weeks before surgery

Sponsors

Gelderse Vallei Hospital
CollaboratorOTHER
Rijnstate Hospital
CollaboratorOTHER
Wageningen University
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
60 Years to 80 Years
Healthy volunteers
No

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.

Design outcomes

Primary

MeasureTime frameDescription
Change in tissue-specific protein synthesis ratesDuring the 2-week preoperative periodTissue-specific protein synthesis rates in the knee using D2O dosing methodology

Secondary

MeasureTime frameDescription
Change in blood pressureMeasured at baseline and 1 day before surgeryBlood pressure measurement using an CE-certified ambulatory blood pressure monitor
Change in plasma amino acidsDuring the 2-week preoperative periodDifference in circulating concentrations between the two diets. In addition, it will be investigated if plasma amino acids can be used as a marker for dietary intake.

Countries

Netherlands

Contacts

Primary ContactInge Groenendijk, PhD
inge.groenendijk@wur.nl+31628748271
Backup ContactLisette de Groot, PhD
lisette.degroot@wur.nl

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026