Vegan and Omnivorous Diets and Skeletal Muscle Turnover in Healthy Older Adults

Study Overview
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Brief Summary
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Dietary protein intake and physical activity are key to minimise the age-related loss of skeletal muscle mass. While animal-derived protein sources are considered high-quality anabolic foods, it remains unclear whether non-animal-derived (vegan) protein sources support skeletal muscle maintenance and healthy ageing. The aim of the present study is to assess the effect of a vegan diet on daily muscle protein synthesis rates compared to a protein-matched omnivorous diet where the majority of protein is derived from high-quality animal-based protein sources.

Detailed Description
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Background: The age-related loss of muscle mass and strength is (partly) explained by a blunted responsiveness of skeletal muscle to the anabolic properties of dietary protein and muscle contraction. Therefore, sufficient dietary protein intake and physical activity are required to minimise age-related muscle atrophy. It remains unknown whether this can be achieved utilising non-animal-derived (vegan) protein sources. Objective: To assess daily muscle protein synthesis rates when adopting a vegan or protein-matched omnivorous control diet. Methods: Healthy older adults (aged 60-80 years) will be randomly allocated to a completely controlled 1-week vegan (providing 0.8 g/kg BW/day protein) or protein-matched omnivorous diet. During this week, participants will perform a set of unilateral leg resistance exercise on day 1, 3, and 5. Deuterium oxide in combination with saliva and muscle sample (from the m. vastus lateralis) collection will be used to measure daily muscle protein synthesis rates in resting and exercised tissue. Value: This will be the first study assessing daily muscle protein turnover in healthy older adults adopting a 1-week vegan diet. This will contribute to the understanding and viability of vegan protein to support active and healthy ageing.

Official Title
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The Effects of a High-quality Vegan Diet on Skeletal Muscle Maintenance and Adaptation in Comparison to a Protein-matched Omnivorous Diet in Healthy Older Adults.

Conditions
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Healthy Aging

Intervention / Treatment
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* Other: Controlled diet and resistance exercise


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: BMI between 18.5 - 30 Active (not very sedentary and not master athlete; assessed via IPAQ) Women only: post menopause Exclusion Criteria: Hypertension (>150/90 mmHg) Any diagnosed metabolic impairment Any diagnosed cardiovascular disease Any diagnosed gastrointestinal disease Diagnosed cancer Any medication known to affect muscle metabolism (e.g. hormone replacement therapy) Severe food allergies or intolerances (e.g. celiac, lactose intolerance, allergic to fungi or algae foods) Smoking

Ages Eligible for Study
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Minimum Age: 60 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Vegan diet<br>Participants will be allocated to a fully controlled 1-week vegan diet containing 0.8 g/kg BW/day of protein where all protein provided will be derived from non-animal-derived protein sources. | Other: Controlled diet and resistance exercise<br>* Participants will adopt a 1-week completely controlled diet and perform 3 sessions of unilateral leg resistance exercise.<br>|
| Experimental: Omnivorous diet<br>Participants will be allocated to a fully controlled 1-week omnivorous diet containing 0.8 g/kg BW/day of protein where the majority of protein will be derived from animal-derived protein sources. | Other: Controlled diet and resistance exercise<br>* Participants will adopt a 1-week completely controlled diet and perform 3 sessions of unilateral leg resistance exercise.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Muscle protein synthesis (MPS) in resting and exercised tissue | Daily MPS rates, expressed as fractional synthetic rate (%/h) | 7 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Muscle morphology | Changes in muscle thickness during the intervention period, measured via ultrasound | 7 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Muscle metabolism, Protein metabolism, Sarcopenia, Resistance exercise