The Side Effects Of Omega 3 Fish Oil

The Food and Drug Administration supports the qualified health claim, "Supportive but not conclusive research shows that consumption of EPA and DHA omega-3 fatty acids may reduce the risk of coronary heart disease." According to the University of Maryland Medical Center (UMMC) omega-3 fatty acids from fish oil have been linked to benefits associated with heart health, diabetes, lupus, osteoporosis, depression, psychological disorders, skin disorders, macular degeneration, asthma and certain cancers. Omega-3 fish oil is available through food sources and supplements, the latter of which can cause side effects.

Bleeding

The UMMC recommends individuals who bruise easily, suffer from bleeding disorders, or are on blood-thinning medications to take omega-3 fish oil supplements cautiously. Medline Plus, a service of the National Institutes of Health, says that omega-3 fatty acids have a bleeding risk and high doses have been associated with nosebleeds and blood in the urine. This may be due to a mechanism of fish oil that prolongs bleeding times, prevents blood clot formation and breaks down existing blood clots. Medications that may negatively interact with fish oil supplements include aspirin, warfarin or coumadin and plavix.

Gastrointestinal Upsets and Taste

The American Heart Association released a scientific statement about fish oil and omega-3s in 2003 in their publication "Circulation." The most common side effects and deterrents of fish oil mentioned in the report were fishy aftertaste, gastrointestinal problems and nausea. Other negative side effects that have been reported with fish oil supplements are diarrhea, burping, acid reflux/heartburn, bloating and abdominal pain. Medline Plus recommends taking fish oil supplements with meals and starting with a low dose that gradually increases to minimize side effects.

Decreased Blood Pressure

Medline Plus states that multiple studies show that omega-3 fatty acids cause small reductions in blood pressure. This benefits individuals who suffer from high blood pressure, but can be dangerous for people with existing low blood pressure, or who are on medications that lower blood pressure.

Increased Blood Sugar

According to the UMMC, fish oil supplements are associated with increasing fasting blood glucose (sugar), and may interact with diabetic medications that lower blood glucose like glipizide, glyburide, metformin and insulin. Medline Plus states that there is no evidence to suggest that fish oil supplements have a long-term effect on blood glucose; however, diabetics should consult a physician prior to taking a fish oil supplement.

Mercury

Fish is one of the best sources of omega-3 fatty acids, but some fish also contain mercury and contaminants, which can be dangerous for pregnant women and children. Federal guidelines recommend that these populations eat up to 12 ounces of fish weekly from low-mercury fish like salmon, halibut, canned tuna, mahi-mahi, cod and snapper to gain the benefits of omega-3 fatty acids without putting themselves at risk. Shark, mackerel, swordfish and tilefish should be avoided entirely. According to Medline Plus, since mercury is mostly found in fish meat, fish oil supplements are safe during pregnancy because they do not contain mercury.

Additional Side Effects

Medline Plus recommends that individuals with allergies or sensitivities to fish not take omega-3 fish oil supplements. Rare side effects that have been reported with omega-3 fish oil supplements include rash, increased liver function tests, and psychological disorders in people who are bipolar or suffer from depression.