Fish Oil Supplements Side Effects

A jar of fish oil supplements
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Omega-3 fatty acids, which include foods and supplements containing eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and alpha-linolenic acid (ALA) have been shown to have a variety of health benefits. Studies have shown that consuming anywhere between 2 and 4 grams of omega-3 fatty acids daily can lower your triglyceride levels by anywhere between 20 and 45 percent. The American Heart Association (AHA) recommends consuming obtaining these fats from foods, such as:

  • Fatty fish (salmon, anchovy, herring, tuna): The AHA suggests consuming two servings of fatty fish per week.
  • Nuts: Studies have shown that a handful of nuts: such as walnuts, pecans, or almonds: can have a positive impact on your lipid profile.
  • Oils: Cooking with certain oils, such as canola, olive, and vegetable oils are higher in omega-3 fats in comparison to other oils.

However, if you do not want to consume the recommended servings of fatty fish per week or don’t like other omega-3 fat-containing foods, you may look to fish oil supplements to obtain your omega-3 fats.

Although using over-the-counter fish oil may seem like an easier—and less harmful—way of improving your heart health and triglyceride levels, there are side effects associated with using them. These side effects appear to be dose-dependent—that is, the higher the dose that you take, the more likely you will experience one or more of these side effects.

Side Effects

The most commonly noted side effects associated with using fish oil include:

  • Nausea
  • Diarrhea
  • Heartburn
  • Abdominal pain
  • “Fish burp"—belching with a fish-like aftertaste

Taking high doses of omega-3 fats—including those found in fish oil supplements—may interact with certain medications. This especially holds true if you are taking blood thinners or have diabetes. Doses of omega-3 fatty acids that are higher than 3 grams could increase your risk of bleeding—even if you are not taking a medication that could thin your blood. Additionally, high doses of omega-3s found in fish oil may slightly increase your blood sugar levels. In these cases, your healthcare provider may decide to modify—or discontinue—your dosing of fish oil.

If you want to use fish oil supplements to lower your triglycerides, you should discuss this with your healthcare provider first.

If you take fish oil supplements and are experiencing any of the above side effects, there are ways to you can minimize them. However, if the side effects become too bothersome, you should discontinue the fish oil and talk to your healthcare provider about other options to lower your triglycerides.

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Article Sources

  • Dipiro JT, Talbert RL. Pharmacotherapy: A Pathophysiological Approach, 9th ed 2014.
  • Micromedex 2.0.  Truven Health Analytics, Inc. Greenwood Village, CO.