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Is your fish oil toxic?

By now most people know that eating fish weekly or taking a fish oil supplement is a recommended guideline to get healthy fats, support the brain, cardiovascular function, and immune health. This is why I prescribe fish oil to my patients as a part of their naturopathic medical treatment plan. But have you ever thought about the quality of your fish oil and how it is made?

The components of fish oil, EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) are naturally occurring omega-3 essential fatty acids found in fish. These are essential to our diet because the human body cannot make them which makes it of vital importance that you have a quality fish oil. There are also fewer dietary sources of EPA and DHA making supplemental fish oils imperative.

Types of Fish Oil Products

EPA and DHA in the triglyceride form are easily and naturally processed by the body. The fish oil is absorbed in the gut where it is broken down and then reassembled as a triglyceride. (2)

In addition to the triglyceride form of fish oil, there is another kid on the block – ethyl ester. Fish oils in this form are a much different product. Ethyl ester is an alcohol used to extract the EPA and DHA from fish. It is a way to eliminate toxicity – which sounds good right? However, it’s really creating more toxicity and processing for the body to do.

The Problem with Fish Oil Ethyl Esters

Making a quality triglyceride fish oil supplement is a much more expensive process to go through. Ethyl ester derived fish oil is more cost efficient and allows for the industry to use a lesser quality of fish. Making an ethyl ester fish oil requires heating the oil at high temperature which results in concentrating the EPA and DHA with the ethyl ester. As a result important anti-inflammatory molecules are eliminated and a synthetic fish oil product is created. Ethyl esters are also a much less stable form and create more harmful byproducts in the body. (1)

Ethyl Esters in the Body

The metabolism of an ethyl ester fish oil is completely different than a triglyceride fish oil. Why does this matter? Because it results in free radicals which put a greater burden on the body.

An ethyl ester fish oil is processed in the liver, unlike the triglyceride form that is processed in the gut. Once in the liver the ethyl ester is separated from the DHA and EPA. For the body to use these free fatty acids it now has to get a glycerol (sugar) molecule to rebuild it as a triglyceride. The liver is then left with the ethyl ester which will get oxidized resulting in inflammation, counter to the purpose of fish oil. There are also several side effects which have been documented with the prescription fish oil supplement Lovaza, an ethyl ester fish oil. (2) One of the side effects includes increasing triglycerides – which does not happen when taking the triglyceride fish oil form.

Take Home

Today’s diets do not get sufficient amounts of EPA and DHA so taking a fish oil supplement is essential for optimal health. Ensuring that your fish oil is a triglyceride form delivers the highest quality and concentration. You can find my favorite fish oil triglycerides here:

  1. A Comparison of Synthetic Ethyl Ester Form Fish Oil vs. Natural Triglyceride Form (PDF) – Douglas MacKay, ND
  2. Fish oil Triglycerides Vs Ethyl Esters – Short Hills Ophthalmology
  3. Fish Oil Triglycerides vs Ethyl Esters – Designs for Health

By now we all know that eating fish weekly or taking a fish oil supplement is the recommended guideline to get healthy fats. We have also learned that getting in those omega-3s and omega-6s can be very effective in supporting brain health, cardiovascular function, and immune health.

Let’s break it down a little more into the main components of fish oil and their function, EPA and DHA. EPA is eicosapentaenoic acid and DHA is docosahexaenoic acid and they both originate in algae. Fish eat the algae and this is taken up by their cells and concentrated so that when we consume fish we get the beneficial fats. Fish oil is considered an essential fatty acid because humans cannot make it in the body, except DHA is made in breast milk.

EPA and DHA each play significant roles in the body. Both are polyunsaturated fatty acids (PUFA) which are considered the “good fats” in nutrition.

Dr. Laura Enfield, ND, LAc

Dr. Laura Enfield is a California licensed naturopathic doctor and acupuncturist. She is an expert in helping people with acute and chronic joint pain, digestive issues, fatigue, insomnia, weight gain, and thyroid issues.

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