What’s The Difference Between Triglyceride And Ethyl Ester Omega-3 Fish Oil?

When it comes to Omega-3 fish oil supplements, understanding the difference between triglyceride vs ethyl ester is essential for your health. The type of omega-3 affects how well your body absorbs it and how effective it is once inside. 

This article explains why the distinction matters, how to tell if your fish oil is in triglyceride form, and more. We also answer questions like “Are omega-3 acid ethyl esters the same as fish oil?” and discuss the merits of molecularly distilled fish oil.

What Are Omega-3 Triglycerides and Ethyl Esters?

To better understand the differences between these two types of fish oil, let’s break it down:

What are Omega-3 Triglycerides?

Triglycerides (TG) are the natural form of omega-3 found in fish. ¹ These make up about 95% of fats in your diet and are how fats are typically stored in the body. 

Omega-3 triglycerides contain three fatty acids attached to a glycerol backbone. The two primary omega-3 fatty acids are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), though there are other types, too.

What are Omega-3 Ethyl Esters?

Ethyl esters (EE) omega-3s are created in a lab. The fatty acids are separated from their glycerol backbone, and each fatty acid is attached to an ethanol molecule (alcohol) through a process called trans-esterification. 

This process helps concentrate the fish oil and remove impurities. Companies can only create high-strength EPA and DHA omega-3 supplements free from contaminants by using this process. Without concentrating the fish oil, it’s extremely difficult to get a proper dose of omega-3. 

For example, a supplement like cod liver oil that’s not concentrated has a very low level of EPA and DHA. They also often cause stomach upset and other side effects due to their impurities. ²

Triglyceride vs Ethyl Ester: 4 Reasons To Buy Triglyceride Fish Oil

From better absorption to longer shelf life, triglyceride omega-3 supplements offer several key advantages that make it the superior choice for your health.

#1 – Triglyceride fish oil is the natural form

Triglyceride fish oil, being in its natural form, has much higher bioavailability than omega-3 ethyl esters. ^{3 4 5} That means your body can absorb and use more EPA and DHA from triglyceride fish oil than from ethyl esters. ⁶

#2 – Triglyceride omega-3 is better absorbed and processed

Research shows that omega-3 in triglyceride form is up to 71% better absorbed than the ethyl ester form. ^{2 7}

On the other hand, EE fish oil is 10 to 50 times less efficiently processed by the body because of its unnatural chemical structure. It needs to be processed differently by enzymes before it can be absorbed, making the whole process slower and less effective. ⁸ This extra processing also means you get less omega-3 into your bloodstream compared to triglyceride fish oil.

#3 – Triglyceride fish oil stays fresh longer than ethyl ester fish oil

Ethyl ester fish oil is more prone to oxidation, meaning it can go rancid faster. ^{9 10 11 12} This is why it’s important to choose a fish oil with antioxidants, e.g. vitamin E tocopherols, to prevent oxidation.

#4 – TG fish oil is better at reducing circulating blood triglyceride levels

Another study reported that triglyceride omega-3 was significantly better at reducing circulating blood triglyceride levels than EE fish oil. ¹³

Circulating triglyceride levels in the blood are a significant cardiovascular disease risk marker. It’s one of the criteria used to diagnose metabolic syndrome. Here’s how much omega-3 to take daily for heart health.

Are Omega-3 Acid Ethyl Esters the Same as Natural Fish Oil?

No, omega-3 acid ethyl esters are not the same as natural fish oil. EE fish oil is technically fish oil concentrate rather than real fish oil.

Legally, it can be called “fish oil” but it’s really semi-synthetic due to the trans-esterification process that bonds ethanol to the fatty acids. Although both ethanol and fatty acids are natural substances, they are never found together in nature.

Only a few manufacturers (including Intelligent Labs) convert ethyl ester omega-3s back into triglyceride form, but many skip this step because it’s costly and time-consuming. It adds around 40% to the raw material costs. Because of this, many omega-3 fish oils in the market are in the artificial EE form and not TG fish oil.

How to Tell If Fish Oil Is in Triglyceride Form?

If you want to know whether your fish oil is in triglyceride vs ethyl ester form, here are two ways to check:

Check the Label

If it doesn’t specify “triglyceride,” it’s likely ethyl ester. Companies that use the more expensive triglyceride form will highlight it. Our Omega-3 label clearly states the following:

Fish Oil Omega-3 Triglycerides (TG) – 2,250 mg, which is broken down into:

• EPA (Eicosapentaenoic Acid) as TG – 1,224 mg
• DHA (Docosahexaenoic Acid) as TG – 816 mg
• Other Omega-3 Fatty Acids as TG – 210 mg

The Polystyrene Test

• Put 20 ml of fish oil in a polystyrene cup (20 ml is about 20 large capsules worth) and leave it for 10 minutes.
• After 10 minutes, if it’s an EE fish oil, it will have leaked through the cup.
• However, if it’s a triglyceride fish oil, it won’t leak (although the triglyceride fish oil may start to leak after 2-3 hours).

Molecularly Distilled Fish Oil: Good or Bad?

Molecular distillation is a purification process used to remove contaminants such as heavy metals, pesticides, and PCBs from fish oil. While some may worry that this process could degrade the oil, it’s actually a necessary step to ensure you’re getting safe and pure omega-3s.

Our Ultra Pure Omega-3 product is molecularly distilled, meaning it’s thoroughly purified without compromising the natural triglyceride form of the fish oil. This guarantees that you’re getting a clean, high-quality Omega-3 supplement free from harmful impurities, while still retaining the omega-3 benefits that matter most. 

To answer the question, molecularly distilled fish oil is definitely a good thing!

How to Tell If Your Fish Oil Is Good Quality?

High-quality fish oil should always be free from harmful contaminants, retain a natural triglyceride form, and be resistant to oxidation. Here’s what to look for:

• Purity: It’s refined to remove contaminants like heavy metals, dioxins, and PCBs.
• Antioxidants: Look for added antioxidants, like vitamin E, to prevent rancidity. 
• Third-Party Testing: Always check if it’s tested by a third party to confirm its quality.

Conclusion

If you’re looking for pure omega-3 fish oil in its natural triglyceride form, try our Ultra Pure Omega-3 supplement. Each 3-softgel serving contains 2,250 mg of superior triglyceride fish oil in the clinically-approved 3:2 EPA:DHA ratio (1,224 mg EPA / 816 mg DHA). 

To conclude, don’t settle for inferior ethyl ester fish oils. Choosing a TG omega-3 fish oil is the best choice you can make for your health. 

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References:

1. Carlier H, Bernard A, Caselli C. Digestion and absorption of polyunsaturated fatty acids. Reprod Nutr Dev. 1991;31(5):475-500. doi:10.1051/rnd:19910501 ↩︎
2. Dyerberg J, Madsen P, Møller JM, Aardestrup I, Schmidt EB. Bioavailability of marine n-3 fatty acid formulations. Prostaglandins Leukot Essent Fatty Acids. 2010;83(3):137-141. doi:10.1016/j.plefa.2010.06.007 ↩︎
3. Lawson LD, Hughes BG. Human absorption of fish oil fatty acids as triacylglycerols, free acids, or ethyl esters. Biochem Biophys Res Commun. 1988;152(1):328-335. doi:10.1016/s0006-291x(88)80718-6 ↩︎
4. Schuchardt JP, Schneider I, Meyer H, Neubronner J, von Schacky C, Hahn A. Incorporation of EPA and DHA into plasma phospholipids in response to different omega-3 fatty acid formulations–a comparative bioavailability study of fish oil vs. krill oil. Lipids Health Dis. 2011;10:145. Published 2011 Aug 22. doi:10.1186/1476-511X-10-145 ↩︎
5. Beckermann B, Beneke M, Seitz I. Vergleich der Bioverfügbarkeit von Eicosapentaensäure und Docosahexaensäure aus Triglyceriden, freien Fettsäuren und Ethylestern bei Probanden [Comparative bioavailability of eicosapentaenoic acid and docasahexaenoic acid from triglycerides, free fatty acids and ethyl esters in volunteers]. Arzneimittelforschung. 1990;40(6):700-704. ↩︎
6. Schuchardt JP, Hahn A. Bioavailability of long-chain omega-3 fatty acids. Prostaglandins Leukot Essent Fatty Acids. 2013;89(1):1-8. doi:10.1016/j.plefa.2013.03.010 ↩︎
7. Neubronner J, Schuchardt JP, Kressel G, Merkel M, von Schacky C, Hahn A. Enhanced increase of omega-3 index in response to long-term n-3 fatty acid supplementation from triacylglycerides versus ethyl esters. Eur J Clin Nutr. 2011;65(2):247-254. doi:10.1038/ejcn.2010.239 ↩︎
8. Yang LY, Kuksis A, Myher JJ. Lipolysis of menhaden oil triacylglycerols and the corresponding fatty acid alkyl esters by pancreatic lipase in vitro: a reexamination. J Lipid Res. 1990;31(1):137-147. ↩︎
9. Analysis of Headspace Volatile and Oxidized Volatile Compounds in DHA‐enriched Fish Oil on Accelerated Oxidative Storage, H. Lee, S.A. Kizito et al. July 2006, Journal of Food Science 68(7):2169 – 2177 DOI:10.1111/j.1365-2621.2003.tb05742.x ↩︎
10. Yoshii H, Furuta T, Siga H, et al. Autoxidation kinetic analysis of docosahexaenoic acid ethyl ester and docosahexaenoic triglyceride with oxygen sensor. Biosci Biotechnol Biochem. 2002;66(4):749-753. doi:10.1271/bbb.66.749 ↩︎
11. Study on Autoxidation Kinetics of Fats by Differential Scanning Calorimetry. 1. Saturated C12−C18 Fatty Acids and Their Esters, Grzegorz Litwinienko, Andrzej Daniluk, and Teresa Kasprzycka-Guttman, Ind. Eng. Chem. Res. 2000, 39, 1, 7–12 Publication Date:December 4, 1999 https://doi.org/10.1021/ie9905512 ↩︎
12. Oxidation Rates of Triacylglycerol and Ethyl Ester Fish Oils, Jenna C. Sullivan Ritter, Suzanne M. Budge, Fabiola Jovica, Anna-Jean M. Reid, First published: 14 February 2015 ↩︎
13. Schuchardt JP, Neubronner J, Kressel G, Merkel M, von Schacky C, Hahn A. Moderate doses of EPA and DHA from re-esterified triacylglycerols but not from ethyl-esters lower fasting serum triacylglycerols in statin-treated dyslipidemic subjects: Results from a six month randomized controlled trial. Prostaglandins Leukot Essent Fatty Acids. 2011;85(6):381-386. doi:10.1016/j.plefa.2011.07.006 ↩︎

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