Can Omega 3 Fish Oil Damage the Liver?

Omega-3 fatty acid supplements, commonly found in fish oil, have few side effects or drug interactions. Despite concerns among consumers and health practitioners, fish oil supplements are not harmful to the liver.

Fat-Soluble Vitamins

• Supplements made from fish liver, such as cod liver oil, may contain high concentrations of vitamin A. In theory, vitamin A from cod liver oil can cause liver problems; taking recommended doses eliminates this risk.

Contaminants

• The meats of certain predatory fish contain large concentrations of mercury, lead and other contaminants. However, these toxins are found in the flesh--not fat--of the animals, so these concerns do not apply to pharmaceutical-grade fish oil supplements.

Liver Function Tests

• The National Institutes of Health notes that fish oil supplements can rarely cause brief level elevations with liver function tests. However, the increase is negligible and there are no serious liver-related problems associated with fish oil.

Considerations

• Some health practitioners recommend that people with advanced liver disease avoid the supplement because of theoretical concerns.

Avoiding Risks

• Some supplement manufacturers offer distilled, purified forms of fish oil that have been tested for contaminants like mercury and dioxin. High-quality supplements are less likely to contain compounds that stress the liver.