Aug 15, 2019
Are Lifestyle Therapies Effective for NAFLD Treatment?
The reduction of intrahepatic lipids is critical for the improvement of Non-alcoholic fatty liver disease (NAFLD). A group of researchers from the German Center for Diabetes Research, including scientists from the Paul Langerhans Institute Dresden (PLID) and the International Research Training Group 2251 between the TU Dresden and the King’s College London, reviewed the currently existing literature to identify the impact of different lifestyle therapies on the treatment of NAFLD. The results of this work have now been published in the Cell Press journal ´Trends in Endocrinology and Metabolism (TEM)`.
Non-alcoholic fatty liver disease (NAFLD) is the most common liver disorder worldwide and encompasses a disease spectrum, ranging from simple steatosis characterized by excessive fat accumulation in the absence of excessive alcohol consumption and inflammation to nonalcoholic steatohepatitis (NASH), liver cirrhosis, and hepatocellular carcinoma. Moreover, insulin resistance and obesity are risk factors for the development of NAFLD. Unfortunately, approved pharmacological agents are still absent, thus leaving its patients and healthcare providers to lifestyle interventions as their sole line of therapy.
“Our review discusses the effect of macronutrient quality and quantity as well as different modalities of exercise training in reducing intrahepatic lipids and improving NAFLD with or without weight loss”, explains Nermeen El-Agroudy, PhD student at International Research Training Group 2251: 'Immunological and Cellular Strategies in Metabolic Disease (IRTG) and one of the first authors of the study. And PhD student Anica Kurzbach, the second first author, adds “Undoubtedly, progressive weight loss leads to continuous reductions in intrahepatic lipids, however, we found studies which also suggest that high fiber and high protein diet as well as Mediterranean diet per se have additional effects on reducing intrahepatic lipids.”
Moreover, physical exercise provides an important mean to reduce intrahepatic lipids independent of change of body composition. Studies showed that regular exercise training not only decreases intrahepatic lipids, but also improves NAFLD-associated comorbidities (e.g. insulin resistance, cardiovascular diseases). This observation led to current applied guidelines recommending 3–5 sessions per week, with a total duration of 150–200 min of moderate intensity. “Although combined aerobic and resistance training showed positive effects in NAFLD patients, the type of exercise or volume and intensity do not seem to be critical in determining reductions of intrahepatic lipids. It is more important to just do exercise, as it improves the outcome of NAFLD or at least its progression” summarizes El-Agroudy. However, evidence from both dietary and exercise interventions is unfortunately still limited regarding their effectiveness on improving more progressive forms of the disease such as steatohepatitis. Thus, the combination of intensified diet and adequate physical exercise would likely be a promising weapon for fighting NAFLD.
Original publication:
El-Agroudy NN, Kurzbach A, Rodionov RN, O'Sullivan J, Roden M, Birkenfeld AL, Pesta DH. Are Lifestyle Therapies Effective for NAFLD Treatment? Trends Endocrinol Metab. 2019 Aug 15. pii: S1043-2760(19)30136-5. doi: 10.1016/j.tem.2019.07.013. [Epub ahead of print] Review.