Who Shouldn't Use Fish Oil?

Fish oil is one of the world's most popular supplements. This nutritional medicine contains large amounts of the omega-3 fatty acids DHA and EPA, which can reduce triglyercides and promote cardiovascular health. Fish oil is used as a holistic treatment option for dozens of common conditions, including depression, macular degeneration, kidney disease and hardening of the arteries. When used as directed, fish oil is very safe and associated with few serious side effects.

However, there are some fish oil contraindications. Some people should not take fish oil because it can cause severe problems for these high-risk individuals. Avoid fish oil supplements if you are in any of these groups.

Bipolar Disorder

Taking fish oil might increase some symptoms of bipolar disorder, so bipolar disorder is sometimes regarded as a fish oil contraindication. There are some cases of people developing symptoms of mania while using fish oil. Unless your health care provider specifically directs otherwise, avoid taking fish oil supplements if you have bipolar disorder or manic-depressive disorder.

Implanted Defibrillators

If you have an implanted defrillator-- a surgically implanted device designed to prevent irregular heartbeat-- you should not take fish oil. Some limited research suggests that fish oil can increase the chance of cardiac arrhythmia, or irregular heartbeat, in patients with implanted defibrillators. Err on the side of caution and avoid fish oil supplements.

Familial Adenomatous Polyposis

Although evidence is limited, some research indicates that fish oil can increase cancer risk in people with familial adenomatous polyposis. Until more is known, FAP is regarded as a fish oil contraindication, and these risks appear to outweigh the potential benefits. Consult your health care provider about other measures you can take to reduce your cancer risk associated with familial adenomatous polyposis.

Compromised Immune Systems

Large doses of fish oil, in excess of three grams per day, are contraindicated for people with compromised immune systems. These high doses may weaken your immune function, making you more prone to infections. If you have HIV/AIDS or take immunosuppressant drugs, do not use large doses of fish oil. Check with your health care provider before using any supplement if you have an immune-suppressing condition.

Bleeding Disorders

You should take fish oil only under the guidance of a health care provider if you have a history of a bleeding disorder such as hemophilia or von Willebrand disease. These conditions may not be absolute fish oil contraindications, but you should use the supplements cautiously and report any changes in bleeding or bruising to your health care provider.