scholarly journals The Effect of Whole Egg Intake on Muscle Mass: Are the Yolk and Its Nutrients Important?

Author(s):  
Heitor O. Santos ◽  
Gederson K. Gomes ◽  
Brad J. Schoenfeld ◽  
Erick P. de Oliveira

Whole egg may have potential benefits for enhancing muscle mass, independent of its protein content. The yolk comprises ∼40% of the total protein in an egg, as well as containing several nonprotein nutrients that could possess anabolic properties (e.g., microRNAs, vitamins, minerals, lipids, phosphatidic acid and other phospholipids). Therefore, the purpose of this narrative review is to discuss the current evidence as to the possible effects of egg yolk compounds on skeletal muscle accretion beyond those of egg whites alone. The intake of whole egg seems to promote greater myofibrillar protein synthesis than egg white intake in young men. However, limited evidence shows no difference in muscle hypertrophy when comparing the consumption of whole egg versus an isonitrogenous quantity of egg white in young men performing resistance training. Although egg yolk intake seems to promote additional acute increases on myofibrillar protein synthesis, it does not seem to further enhance muscle mass when compared to egg whites when consumed as part of a high-protein dietary patterns, at least in young men. This conclusion is based on very limited evidence and more studies are needed to evaluate the effects of egg yolk (or whole eggs) intake on muscle mass not only in young men, but also in other populations such as women, older adults, and individuals with muscle wasting diseases.

2018 ◽  
Vol 50 (5S) ◽  
pp. 370
Author(s):  
Brandon J. Shad ◽  
Andrew M. Holwerda ◽  
Yasir S. Elhassan ◽  
Luc J.C. van Loon ◽  
Janice L. Thompson ◽  
...  

2020 ◽  
Vol 318 (2) ◽  
pp. E117-E130 ◽  
Author(s):  
Sean P. Kilroe ◽  
Jonathan Fulford ◽  
Andrew M. Holwerda ◽  
Sarah R. Jackman ◽  
Benjamin P. Lee ◽  
...  

Short-term muscle disuse has been reported to lower both postabsorptive and postprandial myofibrillar protein synthesis rates. This study assessed the impact of disuse on daily myofibrillar protein synthesis rates following short-term (2 and 7 days) muscle disuse under free living conditions. Thirteen healthy young men (age: 20 ± 1 yr; BMI: 23 ± 1 kg/m−2) underwent 7 days of unilateral leg immobilization via a knee brace, with the nonimmobilized leg acting as a control. Four days before immobilization participants ingested 400 mL of 70% deuterated water, with 50-mL doses consumed daily thereafter. Upper leg bilateral MRI scans and muscle biopsies were collected before and after 2 and 7 days of immobilization to determine quadriceps volume and daily myofibrillar protein synthesis rates. Immobilization reduced quadriceps volume in the immobilized leg by 1.7 ± 0.3 and 6.7 ± 0.6% after 2 and 7 days, respectively, with no changes in the control leg. Over the 1-wk immobilization period, myofibrillar protein synthesis rates were 36 ± 4% lower in the immobilized (0.81 ± 0.04%/day) compared with the control (1.26 ± 0.04%/day) leg ( P < 0.001). Myofibrillar protein synthesis rates in the control leg did not change over time ( P = 0.775), but in the immobilized leg they were numerically lower during the 0- to 2-day period (16 ± 6%, 1.11 ± 0.09%/day, P = 0.153) and were significantly lower during the 2- to 7-day period (44 ± 5%, 0.70 ± 0.06%/day, P < 0.001) when compared with the control leg. We conclude that 1 wk of muscle disuse induces a rapid and sustained decline in daily myofibrillar protein synthesis rates in healthy young men.


2019 ◽  
Vol 51 (10) ◽  
pp. 2125-2134 ◽  
Author(s):  
BRANDON J. SHAD ◽  
JANICE L. THOMPSON ◽  
ANDREW M. HOLWERDA ◽  
BEN STOCKS ◽  
YASIR S. ELHASSAN ◽  
...  

2020 ◽  
Vol 598 (8) ◽  
pp. 1523-1536 ◽  
Author(s):  
Nicholas J. Saner ◽  
Matthew J.‐C. Lee ◽  
Nathan W. Pitchford ◽  
Jujiao Kuang ◽  
Gregory D. Roach ◽  
...  

Metabolites ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 84
Author(s):  
Yeongmin Kim ◽  
Sanghee Park ◽  
Jinseok Lee ◽  
Jiwoong Jang ◽  
Jiyeon Jung ◽  
...  

Dexamethasone (DEX) induces dysregulation of protein turnover, leading to muscle atrophy and impairment of glucose metabolism. Positive protein balance, i.e., rate of protein synthesis exceeding rate of protein degradation, can be induced by dietary essential amino acids (EAAs). In this study, we investigated the roles of an EAA-enriched diet in the regulation of muscle proteostasis and its impact on glucose metabolism in the DEX-induced muscle atrophy model. Mice were fed normal chow or EAA-enriched chow and were given daily injections of DEX over 10 days. We determined muscle mass and functions using treadmill running and ladder climbing exercises, protein kinetics using the D2O labeling method, molecular signaling using immunoblot analysis, and glucose metabolism using a U-13C6 glucose tracer during oral glucose tolerance test (OGTT). The EAA-enriched diet increased muscle mass, strength, and myofibrillar protein synthesis rate, concurrent with improved glucose metabolism (i.e., reduced plasma insulin concentrations and increased insulin sensitivity) during the OGTT. The U-13C6 glucose tracing revealed that the EAA-enriched diet increased glucose uptake and subsequent glycolytic flux. In sum, our results demonstrate a vital role for the EAA-enriched diet in alleviating the DEX-induced muscle atrophy through stimulation of myofibrillar proteins synthesis, which was associated with improved glucose metabolism.


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