Omega-3 Fatty Acids May Help Reduce Fat Buildup in the Liver by Targeting a Key MicroRNA

This laboratory study looked at how omega-3 fatty acids (EPA and DHA) affect fat buildup in the liver, using both mice fed a high-fat diet and human liver cells (HepG2) exposed to a fat-inducing compound. Researchers focused on a small molecule called miR-34a, which had previously been found at higher levels in people with fatty liver disease.

Mice fed a high-fat diet, and liver cells exposed to palmitic acid, both showed increased miR-34a activity. When researchers gave the mice omega-3 fatty acid supplements (at three different doses) for 8 weeks, blood triglycerides, total cholesterol, and LDL cholesterol dropped, and liver fat content and signs of fatty liver on tissue exam were reduced. At the same time, miR-34a levels went down, along with a fat-storage gene (SREBP-1c), while genes linked to fat-burning and energy metabolism (SIRT1, PGC-1α, CPT-1A) went up.

To confirm miR-34a was actually driving these effects, researchers artificially boosted miR-34a in the liver cells alongside omega-3 treatment. This blocked most of the beneficial changes in SIRT1, SREBP-1c, PGC-1α, and CPT-1A that omega-3s normally produced, suggesting miR-34a is a key switch through which omega-3 fatty acids influence fat metabolism in the liver.