Fish Oil

What might you notice after taking it?

Common adverse effects are usually mild: an unpleasant taste, bad breath, heartburn, nausea, abdominal discomfort or diarrhea. These practical drawbacks belong in the comparison alongside any expected benefit. 1

The important caution about atrial fibrillation

Atrial fibrillation is a heart-rhythm disorder. The BfR warns that omega-3 preparations can increase its risk in people with existing heart disease or risk factors. The reviewed trials showed a dose-related pattern, with the greatest risk at 4 g daily. The concern includes both medicines and supplements. 2

For people with heart disease or relevant risk factors, the BfR advises medical discussion before using these products, especially for a longer period. Earlier assessments describing up to 5 g EPA plus DHA daily as generally safe should not be read as a personal target; later trials identified the heart-rhythm signal at lower amounts. 1 2

What if you take an anticoagulant?

Fish oil can affect platelet function at high doses. Most research has not found a significant effect on warfarin anticoagulation at studied fish-oil doses, but omega-3 medicine labels call for monitoring when used with anticoagulants. A pharmacist or prescriber can review the combination; an automatic claim that fish oil always causes dangerous bleeding would overstate the evidence. 1

Pregnancy calls for a separate discussion

EPA and DHA guidance during pregnancy concerns maternal and infant nutrition, not copying heart-treatment doses. NIH summarizes advice to choose lower-mercury seafood and to discuss supplementation with a clinician when following a vegetarian or vegan diet. Cod liver oil also adds vitamins A and D, so it is not equivalent to a product containing only omega-3 fats. 1