Fish Oil

Why “1,000 mg fish oil” can be misleading

Oil weight is not the same as EPA plus DHA. The NIH gives a typical example: 1,000 mg fish oil containing 180 mg EPA and 120 mg DHA. Products vary widely; the named EPA and DHA quantities are the figures that allow comparison with a study. 1

Triglycerides, ethyl esters and alternatives

Fish-oil products may contain natural or re-esterified triglycerides, ethyl esters or other forms. Some forms are absorbed somewhat better than ethyl esters, but all increase blood EPA and DHA. A difference in absorption alone does not establish that a particular product prevents more illness. 1

Algal oil offers DHA without fish oil, with EPA included in some products. Cod liver oil is a different comparison again because it also supplies vitamins A and D. The ingredient list matters as well as the omega-3 amount. 1

Supplements and medicines have different roles

In Germany, the BfR classifies supplements as foods intended to complement the diet, not to heal or relieve disease. Some supplements nevertheless contain amounts similar to medicines. A high number on a freely available product is not evidence that it is appropriate for self-treatment. 2