High-Protein Diet in Hepatic Lipid Accumulation Management of Non-alcoholic Fatty Liver Disease. A Literature Review

Citation

Nguyen AH (2018) High-Protein Diet in Hepatic Lipid Accumulation Management of Non-alcoholic Fatty Liver Disease. A Literature Review. 10th Excellence in Pediatrics Conference, Prague. Cogent Medicine, 5 (1), p. 101, Art. No.: 1544190. https://doi.org/10.1080/2331205x.2018.1544190

Abstract
Hepatic steatosis is the simplest stage in non-alcoholic fatty liver disease (NAFLD), which could precede a more severe stage of hepatocellular inflammation and damage, such as non-alcoholic steatohepatitis (NASH) and cirrhosis, caused by the accumulated fat. Some studies on the effect of high protein (HP) intake to reduced accumulation of hepatic lipids have been published recently, but its long-term effect and the responses of gene expression to HP remain to be fully unexplored. Aims: To assess the effects of protein supplementation against increased intrahepatocellular lipids (IHCL) in long-term intervention studies on humans. Moreover, the author considers studies on humans and rodents, which investigated mechanisms of the regulation of gene expression underlying IHCL reduction in response to HP. Method: A literature search on PubMed and Cumulative Index of Nursing and Allied Health Literature (CINAHL) using the following search terms: hepatic steatosis, HP and gene expression, for relevant articles. Eligible publications are consistent with published intervention studies in English language on adult and rodents (mice or rats). Result: Energy intake total, BMI, body weight and insulin resistance remained unchanged in longterm response to an HP, compared with baseline. Protein intake increased significantly whereas carbohydrate and fat consumption decreased. The IHCL reduction was strongly associated with added protein consumption after 4 weeks, although the evidence was weaker for longer intervention periods. Evidence from studies on humans and rodents demonstrated that increased fatty acid beta oxidation activity through increased uptake of free fatty acids into the mitochondria due to upregulated expressions of Cpt1, CD36, but inhibition of lipogenesis genes when responding to an HP diet. Conclusion: The results of the present review cannot confirm the long-term effect of increased protein intake on IHCL reduction, due to the lack of enough strong evidence in these intervention studies on humans. However, the long-term effect of HP consumption and a spontaneous reduction in carbohydrate and fat intake to maintain caloric balance were strongly linked. There was a strong correlation between beta-fatty acid oxidation and upregulation of translocate protein on outer mitochondrial membrane (Cpt1 and CD36) in response to a HP diet. Cpt1: Carnitine palmitoyltransferase