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- May 2, 2021
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1) Alcohol Impedes Muscle Protein Synthesis
The anabolic response within muscle tissue is due to the difference in muscle protein and muscle protein breakdown, where higher levels of protein synthesis results in muscle growth. This anabolic response within muscle tissue can be significantly decreased by the consumption of excessive alcohol intake, which inhibits muscle protein synthesis and therefore muscle growth.1-3 In fact, one study by Hong-Brown et al. showed that the exposure of muscle cells to alcohol decreased the ability of either IGF-1 or insulin to stimulate protein synthesis by 30 percent and 60 percent, respectively. In addition, this study also showed that alcohol had no influence on the rate of muscle protein degradation4, demonstrating that alcohol specifically affects muscle protein synthesis.
In addition to alcohol ingestion reducing the ability of IGF-1 and insulin to promote muscle growth, alcohol has also been shown to directly suppress mTOR-driven muscle protein synthesis.5 This effect stems from the ability of alcohol to inhibit the production of phosphatidic acid (PA) by the enzyme phospholipase D within the muscle cell. PA is a signaling molecule that has been shown to directly activate mTOR in response to resistance exercise.6 Consequently, the reduction of PA by alcohol lowers mTOR-activated protein synthesis, leading to reduced muscle growth.
The anabolic response within muscle tissue is due to the difference in muscle protein and muscle protein breakdown, where higher levels of protein synthesis results in muscle growth. This anabolic response within muscle tissue can be significantly decreased by the consumption of excessive alcohol intake, which inhibits muscle protein synthesis and therefore muscle growth.1-3 In fact, one study by Hong-Brown et al. showed that the exposure of muscle cells to alcohol decreased the ability of either IGF-1 or insulin to stimulate protein synthesis by 30 percent and 60 percent, respectively. In addition, this study also showed that alcohol had no influence on the rate of muscle protein degradation4, demonstrating that alcohol specifically affects muscle protein synthesis.
In addition to alcohol ingestion reducing the ability of IGF-1 and insulin to promote muscle growth, alcohol has also been shown to directly suppress mTOR-driven muscle protein synthesis.5 This effect stems from the ability of alcohol to inhibit the production of phosphatidic acid (PA) by the enzyme phospholipase D within the muscle cell. PA is a signaling molecule that has been shown to directly activate mTOR in response to resistance exercise.6 Consequently, the reduction of PA by alcohol lowers mTOR-activated protein synthesis, leading to reduced muscle growth.