According to a new study, diets enriched in two types of saturated fatty acids - palmitic and myristic - induce the development of steatohepatitis, an advanced stage of the fatty liver disease, and promotes fat to accumulate in the liver which causes inflammation. Researchers from the Instituto de Investigaciones Biomédicas de Barcelona (CSIC) and the IDIBAPS have published an article in Oncotarget journal in which they have shown for the first time that diets enriched in two types of saturated fatty acids - palmitic and myristic - induce the development of steatohepatitis, an advanced stage of the fatty liver disease, and promotes fat to accumulate in the liver which causes inflammation. The coordinators of this study are Dr. Jose C. Fernández-Checa, Head of the Mitochondrial Regulation of Cell Death and Steatohepatitis IDIBAPS team, and Dr. Carmen García-Ruiz, researcher at the same team. Dr. Laura Martinez, post-doctoral researcher at Dr. Fernández-Checa’s group, is the first author of the study.
Palmitic acid is a saturated fatty acid present in processed meat products and common in Western diets. It is associated with obesity and insulin resistance. Excessive amounts induce lipoapoptosis (a type of programmed cell death) and causes fatty liver disease, which can lead to cirrhosis or even liver cancer. Myristic acid is found in vegetable oils, common in Eastern diets and, unlike palmitic acid, is not lipotoxic.
In in vitro studies, researchers have found that myristic acid increases the lipotoxicity of palmitic acid by stimulating the synthesis of ceramides, a type of lipid. In vivo studies show that while the consumption of diets enriched either in palmitic or myristic acid does not necessarily produce liver damage, diets rich in both fatty acids induce inflammation accompanied by severe steatohepatitis and liver fibrosis, effects that can be prevented by inhibiting the production of ceramide. Thus, as Drs. Fernández- Checa and Garcia-Ruiz describe: "the abusive consumption of processed food rich in palmitic acid accompanied by diets with myristic acid should be avoided because it can be a risk factor for the development of steatohepatitis".
Reference article:
Myristic acid potentiates palmitic acid-induced lipotoxicity and steatohepatitis associated with lipodystrophy by sustaning de novo ceramide synthesis. Martínez L, Torres S, Baulies A, Alarcón-Vila C, Elena M, Fabriàs G, Casas J, Caballeria J,Fernandez-Checa JC, García-Ruiz C.
Oncotarget. 2015 Dec 8;6(39):41479-96. doi: 10.18632/oncotarget.6286.