Vegan Diets: the Short-term Effects on Daily Muscle Protein Synthesis Rates as Compared to Omnivorous Diets in Older Adults Assessed by D2O.

Study Overview
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Brief Summary
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Consumers are increasingly encouraged to consume more plant-based foods and lower their consumption of foods from animal origin. However, the consequences of such a transition on muscle mass still remains to be explored. This is of particular importance in the older population, where sarcopenia is highly prevalent. The aim of this randomized controlled cross-over study is to investigate the short-term effect of a 10-day controlled vegan diet on daily muscle fractional synthesis rates in comparison to a 10-day controlled omnivorous diet in 35 community-dwelling older adults. Participants will follow a fully controlled vegan diet, directly followed by a fully controlled omnivorous diet for 10 days, or vice versa. Researchers will compare the effect of the vegan diet to the effect of the omnivorous diet.

Official Title
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Vegan Diets: the Short-term Effects on Daily Muscle Protein Synthesis Rates as Compared to Omnivorous Diets in Older Adults Assessed by D2O.

Conditions
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Sarcopenia

Intervention / Treatment
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* Other: Vegan diet (intervention)
* Other: Omnivorous diet (control)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Aged 65-79 years old; Community-dwelling; BMI 20-35 kg/m^2. Exclusion Criteria: Following a vegetarian or vegan diet during the six months prior to the study; Following a diet that affects protein intake during the six months prior to the study; Participating in a structured exercise training program in the past three months; 5% or more body weight loss during three months before the start of the study; Being diagnosed with one of the following: diabetes; renal disease; neurological or neuromuscular disorders; serious cardiovascular diseases; cancer; chronic obstructive lung disease (COPD); Chronic use of medication that affects muscle function, e.g. corticosteroids, metformin, insulin; The use of the following medicines: acenocoumarol (sintrom); phenprocoumon (marcoumar); dabigatran (pradaxa); apixaban (eliquis); rivaroxaban (xarelto); clopidogrel (plavix); combination of acetylsalicylic acid or carbasalate calcium (ascal) with dipyridamole. Allergic or intolerant to any product included in the diets; Not willing to stop nutritional supplements, with the exception of supplements on medical advice, and vitamin D; Not willing or afraid to give blood or undergo a muscle biopsy during the study; Unwilling to eat a vegan and an omnivorous diet for ten days each; Currently a research participant in another trial or participated in a clinical trial during three months before the start of the measurement period; Not being able to understand Dutch; Not having a general physician.

Ages Eligible for Study
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Minimum Age: 65 Years
Maximum Age: 79 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: Supportive Care
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: VO group<br>Vegan diet followed by Omnivorous diet | Other: Vegan diet (intervention)<br>* The intervention diet will be a fully controlled vegan diet that will be consumed for a duration of 10 days. No animal-based food products will be included in the diet.<br>Other: Omnivorous diet (control)<br>* The control diet will be an a priori composed controlled omnivorous diet with a duration of 10 days. The omnivorous diet and the vegan diet will be isocaloric and isonitrogenous.<br>|
| Other: OV group<br>Omnivorous diet followed by Vegan diet | Other: Vegan diet (intervention)<br>* The intervention diet will be a fully controlled vegan diet that will be consumed for a duration of 10 days. No animal-based food products will be included in the diet.<br>Other: Omnivorous diet (control)<br>* The control diet will be an a priori composed controlled omnivorous diet with a duration of 10 days. The omnivorous diet and the vegan diet will be isocaloric and isonitrogenous.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Muscle Protein Synthesis (MPS) | MPS, expressed as daily fractional synthesis rates (FSR, %/day), will be assessed using a deuterium oxide protocol. Daily FSR will be calculated using the 2^H-alanine enrichment in plasma and the mixed muscle-bound 2^H-alanine enrichment. | 10 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Appetite | Appetite will be assessed using visual analogue scales (VAS; Min 0 mm - max 100 mm) before and after the warm meal. Five VAS-scales regarding hunger, fullness, satiation, desire to eat and prospective food consumption will be used to assess appetite. | Measured daily for 10 days during each diet | 
| Change in fasting plasma glucose | Fasting plasma glucose levels | Change after 10 days of following each diet | 
| Change in fasting plasma insulin | Fasting plasma insulin levels | Change after 10 days of following each diet | 
| Change in fasting plasma lipid profile | Triglycerides, high-density lipoprotein-cholesterol, low-density lipoprotein cholesterol, total cholesterol | Change after 10 days of following each diet | 
| Change in blood pressure | Fasting systolic and diastolic blood pressure | Change after 10 days of following each diet |