This study will evaluate the adaptations in skeletal muscle that occur in response to 10 weeks of weight training with or without peanut protein supplementation in older adult men and women.
Aging is associated with declines in muscle mass, physical strength and physical function. Adequate quality protein intake in aging adults is critical to preventing functional decline. Peanuts provide a unique blend of amino acids that can provide several health benefits to aging adults. While supplementing with peanut protein (PP) powder as part of a resistance training program may increase myofibrillar protein synthesis (i.e., the gold standard molecular assessment in deciphering a muscle-building response), and improve skeletal muscle quality and body composition, no study to date has made this determination. This is a two-phase study using both novel and conventional methods to assess how PP supplementation affects muscle tissue in older individuals who engage in resistance training. These two phases will be conducted as part of a 10-week randomized controlled trial in which men and women aged 50 years and older (n=60), will be stratified by gender and randomized to a resistance training intervention (whole body, two days per week) with PP powder (72g daily; n=15 males, n=15 females) provided during the intervention (immediate group, IG) or after the intervention (wait-list control, WLC, n=15 males, n=15 females). The aims of this study are to determine the acute (deuterium oxide tracer) and chronic (peripheral quantitative computed tomography) effects of PP during resistance training on skeletal muscle myofibrillar protein synthesis rates, changes in skeletal muscle size and quality, changes in whole and appendicular body composition (dual energy x-ray absorptiometry), changes in inflammatory markers and the fecal microbiome.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
DOUBLE
Enrollment
41
Peanut protein powder will be provided to participants who will be instructed to consume 72g daily, mixed with water
Participants will undergo supervised resistance training two times per week (5 exercises, 3 sets of 8-12 repetitions per set)
Auburn University
Auburn, Alabama, United States
Change in acute myofibrillar protein synthesis rates
Change in right leg vastus lateralis myofibrillar protein synthesis rates using the integrated deuterium oxide technique from biopsies immediately before and 24 hours after resistance exercise
Time frame: 24 hours
Change in mid-thigh skeletal muscle area and quality
peripheral quantitative computed tomography (pQCT) cross-sectional image of mid-right thigh assessed for total muscle cross-sectional area, subcutaneous adipose tissue area, total intra- and inter-muscular adipose tissue area and overall muscle density
Time frame: 0-10 weeks
Change in whole-body and appendicular body composition
dual energy x-ray absorptiometry (DXA)
Time frame: 0-10 weeks
Change in Type I and II Muscle Fiber Cross-Sectional Area
Muscle biopsy immunofluorescent staining for determination of type I and type II muscle fiber cross sectional area (fCSA) as a cellular determinant of skeletal muscle hypertrophy
Time frame: 0-10 weeks
Change in leg extensor isokinetic dynamometry
maximal isokinetic right leg extensions on an isokinetic dynamometer (BioDex)
Time frame: 0-10 weeks
Change in inflammatory biomarkers
serum C-reactive protein, interleukin-6, tumor necrosis factor-alpha, plasma 8-hydroxy-2'deoxyguanosine
Time frame: 0-10 weeks
Change in fecal microbiome composition
alpha- and beta-diversity of 16S bacterial rDNA
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Time frame: 0-10 weeks