the effect of a 12-week self-composed vegan diet with or without concurrent resistance exercise on thigh muscle volume in older adults

Conditions: Vegan Diet; Sarcopenia; Cardiovascular Health; Osteoporosis; Gut Health

Summary: consumers are increasingly encouraged to consume more plant-based foods and lower their consumption of foods from animal origin. this shift is driven by environmental and health factors. 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 the age-related reduction in muscle mass and strength is highly prevalent. adequate dietary intake, specifically protein intake, is a well-known strategy in promoting muscle mass in older adults. plant-based foods are currently considered to be inferior to animal-based foods in their protein quality, and are therefore considered to be suboptimal for the maintenance of muscle mass at an older age. on the other hand, combining plant-based foods may improve the protein quality and thereby the anabolic properties of a vegan meal. evidence regarding the anabolic properties of vegan diets in older adults is scarce. as such, the current study aims to assess 1) the effects of a 12-week self-composed vegan diet in comparison to an omnivorous diet on thigh muscle volume (tmv) in community-dwelling older adults and 2) the effect of a 12-week self-composed vegan diet combined with twice-weekly resistance exercise (re) on tmv in comparison to a self-composed vegan diet without resistance exercise in community-dwelling older adults.


Eligibility criteria:
inclusion criteria: * aged ≥65 years old; * community-dwelling; * bmi 23-32 kg/m2; * habitual diet contains animal-based food products (i.e. dairy, meat and/or fish) at least 5 days per week; exclusion criteria: * following a self-reported entirely vegetarian or vegan diet during the six months prior to the study; * following a prescribed high (≥1.2 g/kg/d) or low protein diet (\<0.8 g/kg/d), and/or or taking protein supplements on medical advice, during the month prior to the study; * participating in a structured progressive resistance exercise training program the during three months prior to the study; * ≥4 kg of body weight loss during three months before the start of the study; * being diagnosed with one of the following: diabetes mellitus; renal disease; neurological or neuromuscular disorders; serious cardiovascular diseases; cancer (with the exception of the following types of skin cancer: basal cell carcinoma, squamous cell carcinoma); (very) severe chronic obstructive lung disease (copd; gold stage iii or iv); bowel disease. * chronic use of medication that affects muscle function as assessed by the research physician; * the use of anticoagulants incompatible for muscle biopsies as assessed by the research physician: acenocoumarol (sintrom); phenprocoumon (marcoumar); dabigatran (pradaxa); apixaban (eliquis); rivaroxaban (xarelto); clopidogrel (plavix); edoxaban (lixiana); combination of acetylsalicylic acid or carbasalate calcium (ascal) with dipyridamole; * having a contra-indication to mri scanning (including, but not limited to): * pacemakers and defibrillators * infraorbital or intraocular metallic fragments * ferromagnetic implants * claustrophobia * having a hip prosthesis * not willing to stop nutritional supplements, with the exception of supplements on medical advice, and vitamin d; * not willing or afraid to give blood, undergo a muscle biopsy or have an mri scan during the study; * unwilling to eat a self-composed vegan diet or an omnivorous diet with daily consumption of animal-based food sources for 3 months; * unwilling to participate in re twice a week for 3 months; * currently a research participant in another trial or participated in a clinical trial during one month before the start of the measurement period; * not being able to understand dutch; * not having a general physician; * working, or having a direct family member that work at the division of human nutrition at wageningen university during the study. * unwilling to be informed about incidental findings of pathology and approving of reporting this to their general physician.