Does supplementation with leucine-enriched protein alone and in combination with fish-oil-derived n–3 PUFA affect muscle mass, strength, physical performance, and muscle protein synthesis in well-nourished older adults? A randomized, double-blind, placebo-controlled trial

peer-reviewedBackground Leucine-enriched protein (LEU-PRO) and long-chain (LC) n–3 (ω–3) PUFAs have each been proposed to improve muscle mass and function in older adults, whereas their combination may be more effective than either alone. Objective The impact of LEU-PRO supplementation alone and combined with LC n–3 PUFAs on appendicular lean mass, strength, physical performance and myofibrillar protein synthesis (MyoPS) was investigated in older adults at risk of sarcopenia. Methods This 24-wk, 3-arm parallel, randomized, double-blind, placebo-controlled trial was conducted in 107 men and women aged ≥65 y with low muscle mass and/or strength. Twice daily, participants consumed a supplement containing either LEU-PRO (3 g leucine, 10 g protein; n = 38), LEU-PRO plus LC n–3 PUFAs (0.8 g EPA, 1.1 g DHA; LEU-PRO+n–3; n = 38), or an isoenergetic control (CON; n = 31). Appendicular lean mass, handgrip strength, leg strength, physical performance, and circulating metabolic and renal function markers were measured pre-, mid-, and postintervention. Integrated rates of MyoPS were assessed in a subcohort (n = 28). Results Neither LEU-PRO nor LEU-PRO+n–3 supplementation affected appendicular lean mass, handgrip strength, knee extension strength, physical performance or MyoPS. However, isometric knee flexion peak torque (treatment effect: −7.1 Nm; 95% CI: −12.5, −1.8 Nm; P < 0.01) was lower postsupplementation in LEU-PRO+n–3 compared with CON. Serum triacylglycerol and total adiponectin concentrations were lower, and HOMA-IR was higher, in LEU-PRO+n–3 compared with CON postsupplementation (all P < 0.05). Estimated glomerular filtration rate was higher and cystatin c was lower in LEU-PRO and LEU-PRO+n–3 postsupplementation compared with CON (all P < 0.05). Conclusions Contrary to our hypothesis, we did not observe a beneficial effect of LEU-PRO supplementation alone or combined with LC n–3 PUFA supplementation on appendicular lean mass, strength, physical performance or MyoPS in older adults at risk of sarcopenia. This trial was registered at clinicaltrials.gov as NCT03429491.Horizon 2020 Framework ProgrammeThis work was supported by the Department of Agriculture, Food and the Marine Food Institutional Research Measure grant entitled NUTRIMAL “Novel Nutritional Solutions for the Prevention of Malnutrition” (grant 14F822), the European Union’s Horizon 2020 Research and Innovation Program under the Marie Skłodowska-Curie Grant Agreement No. 666010, and a Research Fellowship awarded to CHM by the European Society of Clinical Nutrition and Metabolism (ESPEN). HMR was supported by funding from the Joint Programming Initiative Healthy Diet for a Healthy Life (JPI HDHL) EU Food Biomarkers Alliance “FOODBAll” with Science Foundation Ireland (14/JPHDHL/B3076)

Differences in texture analyses of chicken breast fillets affected by severe wooden breast and spaghetti meat myopathies

Texture of broiler meat is one of the most important attributes for consumers, and it can be affected by breast meat myopathies, such as wooden breast (WB) and spaghetti meat (SM). However, differences in textural measurements between samples can vary by the test applied, meat preparation (raw vs. cooked), and severity of myopathy. Thus, this study employed three tests: compression, Meullenet-Owens razor (MORS), and Allo-Kramer (AK) - to compare normal, WB, and SM fillets. A total of 209 fillets (68 normal, 71 WB, 70 SM) were selected from 3 flocks, at a large commercial processing plant, 3 h after slaughter. The fillets were analyzed for dry matter, crude protein, and fat contents (9 per meat type) as well as pH plus color, and then frozen for later texture analyses (181 fillets; 59 normal, 61 WB, 61 SM). Thawed fillets were submitted to: compression test (raw and cooked), and later cooked samples to the MORS test (blade: 0.5 mm thick, 8.9 mm wide, and the AK test (5 blades, 2 mm blade thickness). Data were analyzed by a mixed model with myopathy and flock as the main effects (SAS, 2013). Normal meat had lower fat content than WB meat (0.91% vs. 1.54%; P<0.05) with intermediate values for SM (1.25%), whereas protein content was higher in normal meat (23.9% vs. 22.3% and 22.7% in WB and SM; P<0.01); similar to previous results. Normal breasts were lighter (188 vs. 230 and 262 g in WB and SM; P<0.01), had lower L* and a* values than abnormal meat, and lower cooking losses (22.4% vs. 27.8% and 26.9% in WB and SM; P<0.001). Raw, normal and SM meat showed lower compression force (5.61 and 4.69 vs. 9.52 N), work (25 and 22 vs. 45 N x mm) and Young's modulus (2.71 and 2.11 vs. 4.29 N/sec) than WB (P<0.001); the same pattern was observed in cooked meat. For the MORS test, SM showed lower shear force (12.8 vs. 14.7 N), work (249 vs. 288 N x mm) and fewer peaks (5.39 vs. 7.57) than normal meat (P<0.01), whereas WB had intermediate values. For the AK test, SM showed lower force (10.5 vs. 14.5 N) and Young's modulus (31.0 vs. 46.0 N/sec) than WB (P<0.01), whereas normal meat had intermediate values. Overall, results revealed that texture tests show different sensitivity with respect to meat preparation and type. The compression test was useful to identify WB even in raw meat as well as in cooked meat. In cooked samples, MORS distinguished SM from normal fillets, whereas the AK test identified SM as different from WB

Behaviour of haematological parameters in athletes performing marathons and ultramarathons in altitude (&apos;skyrunners&apos;)

We observed athletes performing marathons and ultramarathons in altitude over several years to study the behaviour of haematological parameters in order to screen eventual paraphysiological or pathological conditions (sports anaemia). We collected samples from 124 athletes participating in seven races; 23 athletes were recruited in different races: 16 for four times, four for three times, and three for two times. The pre- and post-race values of erythrocytes, haemoglobin and packed cell volume did not show statistically significant differences in the studied athletes. The erythrocytes' indices (MCV, MCH, MCHC) and red cell distribution width (RDW) also were not significantly modified by the strenuous effort. The leukocytes were significantly increased because of immunological involvement during the endurance performance. Platelets and relative indices were not significantly modified. The stability of packed cell volume and haemoglobin in athletes performing training and races in altitude is strong evidence for the use of these parameters as an index of general health status and for illustrating possible abnormal increase because of exogenous stimulation of bone marrow. The preanalytical and analytical accuracy is crucial to assure clinical validity of the collected data: we strictly observed international recommendations in this field

Maximum anaerobic performance of childhood-onset GH-deficient adults

To date, physical capacity of adults with GH deficiency (GHD) has been studied in terms of muscle strength, contractile properties and aerobic performance. As a result, scanty data are available regarding the maximum anaerobic performance of these patients with reference to healthy controls. Therefore, the objective of this study was to evaluate maximum anaerobic power of adults with GHD and of age-matched controls by two methods, one testing lactacid power (w.;(c)) through a 15-s-maximal bout on a bicycle ergometer, the other testing alactic power (w.;(j)) through a vertical jump on a force platform. Absolute w.;(c)and w.;(j)values were both found to be 35% lower(P<0.04) in GHD patients than in controls. Similarly, peak pedalling velocity (V(peak)) was 21% lower (P<0.04) in patients. When w.;(c)and w.;(j)were respectively normalized for thigh and lower limb muscle plus bone volumes and V(peak)for muscle length, differences between patients and controls were no longer significant. Furthermore, the rate of power loss during the cycling bout was approximately 35% in both groups. This observation was in line with similar delta (peak minus baseline) lactate capillary blood concentrations, being 6.3 mM/l in patients and 7.5 mM/l in controls (NS). Lactacid capacity, which represents the energy extracted from lactate metabolism, normalized for body mass was similar in the two groups. In conclusion, the maximum anaerobic power that can be developed by short-statured childhood-onset GHD adults is significantly lower in terms of absolute values, but not different from that of controls once appropriately normalized. Therefore, the changes in maximum anaerobic power of GH deficient patients seem to be a consequence of their smaller muscle mass