Review supports omega-3 for liver health

Increased intakes of omega-3 fatty acids from marine sources may benefit people with non-alcoholic fatty liver disease (NAFLD), says a new review of the literature.

A review of four human studies found that the fatty acids could improve liver health and function, and increase insulin sensitivity in people suffering from fatty liver, a condition that is usually symptomless but said to increase the risk for liver inflammation, and ultimately results in liver failure.

Fatty liver is reportedly on the rise in the US, with between one quarter and one half of Americans, and the prevalence if nonalcoholic fatty liver disease (NAFLD) has increased in line with the ongoing obesity epidemic.

Led by Dr Gail Masterton from the Royal Infirmary of Edinburgh in Scotland, the reviewers report their findings in the journal Alimentary Pharmacology & Therapeutics.

Previous studies have implicated omega-3 in protective benefits against obesity-related conditions. A considerable number of studies already support the benefits of the omega-3 fatty acids eicosapentaenoic acid (EPA, C20:5 n-3) and docosahexaenoic acid (DHA, C22:6 n-3) for cardiovascular health, and cognitive health. Other areas of potential for the fatty acids include mood and behaviour, eye health, cancer risk reduction, and improved infant development.

It is biologically plausible that omega-3 fatty acids may improve liver health, said the reviewers because “they have several potential mechanisms of action, the most important being to alter hepatic gene expression, thereby switching intracellular metabolism from lipogenesis and storage to fatty acid oxidation and catabolism.

“There is also evidence that they improve insulin sensitivity, are anti-inflammatory and reduce TNF levels so offering several potential therapeutic mechanisms,” they added.

“To date the trials have all been open label and none have employed a prospective, randomised, blinded, placebo controlled, adequately powered trial methodology to submit these promising preliminary findings to proper scientific rigour,” wrote Masterton and her co-workers. “Such studies are now urgently required,” they added.