ECSS Paris 2023: OP-PN11
INTRODUCTION: A mycoprotein-rich high-protein vegan diet supports daily myofibrillar protein synthesis (MyoPS) rates to a similar extent as an isonitrogenous omnivorous diet in older adults. However, it remains unclear if vegan diets compromise daily MyoPS and, thus, muscle adaptive responses to exercise at lower protein intakes, especially when consisting of a more diverse array of non-animal-derived foods. We assessed the impact of a vegan diet providing the RDA for protein on daily free-living MyoPS rates over one week, in rested and exercised muscle, compared to a high-quality isonitrogenous omnivorous diet in older adults. METHODS: Twenty-two healthy older adults (male [m]/female [f]; 12/10; age: 67±4 y; BMI: 25±3 kg/m^2) participated in a randomised, parallel-group trial. Following 3 days of consuming their habitual diets, participants consumed a 7-day vegan diet (VEGAN; n=11; m/f, 5/6), providing 0.8 g/kg bm/day of protein (predominantly from mycoprotein, pea, oat, rice, and spirulina-containing foods), or an isonitrogenous omnivorous diet (OMNI; n=11; m/f, 5/6) containing 69% animal-derived protein. On days 1, 3, and 5 of the dietary intervention period participants performed a bout of unilateral resistance exercise. Skeletal muscle and saliva samples were collected during the habitual and dietary intervention periods to assess daily MyoPS in rested and exercised tissue using deuterated water. RESULTS: Dietary protein intake during the intervention period decreased by 26% compared to habitual intakes (P<0.001). Despite this, daily MyoPS rates in rested muscle remained unchanged between the habitual and intervention periods (OMNI: 1.56±0.32 to 1.37±0.24 %/d; VEGAN: 1.53±0.41 to 1.43±0.24 %/d; P=0.81). Resistance exercise increased MyoPS rates by 18% from habitual levels (OMNI: 1.74±0.26 %/d; VEGAN: 1.88±0.28 %/d; P<0.001), resulting in 29% higher MyoPS rates in exercised compared to rested muscle during the intervention (P<0.0001). MyoPS rates were similar between OMNI and VEGAN groups at all time points, in both rested and exercised muscle (all P>0.05). CONCLUSION: A feasible vegan diet incorporating high-quality protein sources, while providing less protein than habitual intakes yet meeting the RDA, supports daily MyoPS rates to a similar extent as an isonitrogenous omnivorous diet. This demonstrates the utility of vegan diets to support skeletal muscle remodelling in older adults.
Read CV Alistair MonteyneECSS Paris 2023: OP-PN11
INTRODUCTION: A global shift towards sustainable food sources is now emerging, largely due to the damaging environmental impact from producing animal foods. Insects are a novel source of sustainable protein due to their high protein content and lower drain on natural resources [1]. This is particularly relevant for older adults, as protein becomes increasingly more important in later life to maintain muscle as we age, which is crucial for reducing frailty, falls and early mortality [2]. We aimed to investigate the digestibility via gastric emptying (GE) of an insect-derived protein compared to whey protein to find out if insects could present a bioavailable source of protein to support human skeletal muscle. A secondary aim was to identify any impact of ageing on the digestibility of insect protein. METHODS: In a randomised double-blind crossover design, 30 healthy adults were separated into three age groups: younger (n=10, 25.9±5.5 yrs), middle (n=10, 46.7±4.9 yrs), and older age (n=10, 76.5±4.2 yrs). After overnight fasting, baseline breath and blood samples were collected. Participants then consumed a cricket or whey protein muffin (20g protein) containing a carbon-13 (13C) octanoic acid tracer to measure GE via expired air as 13CO2. Breath samples were collected at regular intervals for 4-hours postprandially. Blood samples were also collected at the same timepoints to measure plasma amino acid concentration. A week later, the process was repeated with the opposite muffin. Modelling was used to analyse and interpret GE data, determining the time to peak 13C release from the stomach (t lag) and the time for 50% of 13C to empty into the small intestine (t half). One-way and two-way ANOVAs and paired t-tests assessed differences in means between protein sources and age groups, with statistical significance set at p<0.05. RESULTS: Both protein sources resulted in a similar excretion of 13CO2 in all age groups, with ~28% of the 13C recovered at 240 minutes after ingestion for cricket and whey, with no differences between protein sources in t lag or t half (p>0.05). There were also no differences between age groups in t lag or t half for either protein source (p>0.05). CONCLUSION: GE does not appear to differ between cricket and whey protein and is not impacted by ageing. This indicates that the digestibility of an insect protein is similar to that of a well-characterised animal protein in healthy humans. 1. Churchward-Venne TA, Pinckaers PJM, van Loon JJA, et al. Consideration of insects as a source of dietary protein for human consumption. Nutr Rev 2017;75(12):1035-45. doi: 10.1093/nutrit/nux057 2. Traylor DA, Gorissen SHM, Phillips SM. Perspective: Protein Requirements and Optimal Intakes in Aging: Are We Ready to Recommend More Than the Recommended Daily Allowance? Adv Nutr 2018;9(3):171-82. doi: 10.1093/advances/nmy003 [published Online First: 2018/04/11]
Read CV James RutherfordECSS Paris 2023: OP-PN11
INTRODUCTION: The study verified the hypothesis that 3-week supplementation with a free liquid form of beta‐hydroxy‐beta‐methylbutyrate (HMB; 90 mgHMB/kgFat-free mass[FFM]) would result in the improvement in body composition, selected hormones, and indices of isometric knee extension, and the magnitude of these changes will be amplified after introducing high-intensity functional training (HIFT) units as an adjunctive stimulus. METHODS: The randomized double-blind placebo-controlled parallel study was performed in 30 trained (TR; 28.6±9.4 yrs) and 30 untrained (UTR; 33.9±8.0 yrs) males. After the baseline (BAS) visit, participants were randomly allocated into the HMB (TR_HMB, n=15; UTR_HMB, n=15) or the placebo (TR_PLA, n=15; UTR _PLA, n=15) group. There were two 3-week treatment periods: 1) SUP – ingestion of either HMB or PLA and performing the usual training cycle (TR) or lack of training (UTR), and 2) SUP+FGB – ingestion of either HMB or PLA and implementing the additional exercise stimuli (TR and UTR) in the form of two Fight Gone Bad (FGB) workouts per week. The following procedures were performed: body composition (FFM and fat mass [FM]) content using the BodPod®; Cosmed, Italy), total body water content (TBW) using electrical bioimpedance (BIA-101 BIVA Pro ASE, Akern Srl. Italy), blood analysis (cortisol [COR], total and free testosterone [TT and FT]), and maximal voluntary isometric contraction knee extension (Biodex Medical System Inc., New York, USA; peak [PT] and average torque [AT]). RESULTS: BM, FM, or FFM did not change across the study visits in the studied groups. In TR_PLA percentage of TBW was significantly higher at SUP+FGB (63.9±4.3%) compared to BAS (61.4±3.4%) and SUP (63.1±2.9%) visits (p=0.022); TBW in L was significantly higher at SUP (55.4±9.0 L; p=0.041) and SUP+FGB (56.0±9.0 L; p=0.004) compared to BAS (53.7±8.8 L) visit. The concentration of COR and TT did not change in any of the treatment groups. In the TR_PLA group, the concentration of FT was significantly lower at SUP (13.4±3.2 pg/mL) compared to BAS (17.5±7.4 pg/mL; p=0,024). TT/COR or FT/COR did not change in any of the groups. In UTR_PLA absolute and relative PT was significantly higher at SUP+FGB compared to BAS (296±39 vs 281±35 Nm, p=0.003 and 323±56 vs 292±46 Nm/kg, p=0.008); while AT absolute and relative AT were significantly higher at SUP and SUP+FGB compared to BAS (SUP: 279±43 vs 267±31 Nm, p=0.014; SUP+FGB: 286±37 vs 267±31 Nm, p<0.001 and SUP: 304±55 vs 292±46 Nm/kg, p=0.029; SUP+FGB: 312±54 vs 292±46 Nm/kg, p<0.001). CONCLUSION: Regardless of training status, HMB supplementation did not affect body composition, COR, TT, FT concentration, TT/COR, FT/COR, or PT and AT. Surprisingly, PLA supplementation had a favorable effect on TBW content. Moreover, PLA supplementation in combination with HIFT stimuli increased PT and AT. The content of glycerin and the bitter taste of PLA preparation might evoke hydration and ergogenic effects in the studied groups.
Read CV Krzysztof Durkalec-MichalskiECSS Paris 2023: OP-PN11