* Fish Oil Triglyceride vs. Ethyl Ester June 13 2012

Triglyceride Form of the Omega-3 Fish Oil compared to the Ethyl Ester Form -

What are Omega-3 Triglycerides and Ethyl Esters?

In their natural state, as present in the plant and animal tissues, Omega-3 acid molecules are not free floating. They are attached, most frequently in groups of three, to a glycerol backbone. This form of the Omega-3 acids existence is called triglyceride form (same as: TG, triacylglycerol, TAG, or triesters of glycerol, or ester of glycerol and three fatty acids). The Omega-3 acids are stored in living tissues in the triglyceride form*, and the triglycerides essentially form fat tissues. The natural triglyceride (fatty) form of the Omega-3 acids existence is what gave the acids their name - fatty. Thus, the triglyceride form is also the form in which Omega-3 fatty acids exist in natural fish oil.

Ethyl Ester form of the fatty acids does not exist in nature and is created as a result of the chemical reaction with the industrial alcohol in a manufacturing environment.  

Fish oil extracted from fish has relatively low concentrations of the Omega-3 fatty acids, particularly the most sought after EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). In addition, mercury, PCBs, dioxins and furans, which are dangerous contaminants, are now pervasive throughout the planet and make its way into fish. The demand for fish oil with highly concentrated EPA and DHA and the necessity to cleanse the oil from the contaminants led to the invention of the modern molecular distillation process. The molecular distillations process requires breakdown of the glycerol backbone and involves reacting the fatty acids with ethyl ethanol (industrial alcohol). The reaction results in the replacement of the glycerol backbone with the ethyl (alcohol) backbone and formation of the Ethyl Ester form, and strictly speaking, Omega-3 acids in the Ethyl Ester form do not qualify as “Omega-3 fatty acids”.

Upon completion of the molecular distillation, the manufacturer has a clean from contaminants, concentrated Omega-3 fish oil in Ethyl Ester form.  Ethyl Ester is the form, in which the majority of the “pharmaceutical grade” fish oil is sold in the United States.

An additional step in the process can be performed, which would convert the Ethyl Ester oil back into the Triglyceride form; this process is known as re-esterification. However, conversion of the Ethyl Ester form back into the natural Triglyceride form adds approximately 40% of the manufacturing costs that many companies are unwilling to incur. For this reason the majority of the concentrated and purified Omega-3 supplements in the USA are sold in the Ethyl Ester form.


Why Triglyceride (TG) are better than Ethyl Ester (EE)


1.      While there are no conclusive studies to date that demonstrate that ethyl ester has any adverse effects on health, consider that:


·         Triglyceride is the natural form. Omega-3 fatty acids are stored in living tissues as Triglycerides. Ethyl Ester fish oil does not exist in nature, and long term effects of consuming this form of the long chain acids are unknown;

·         Ethyl Ester form of the Omega-3 acids has to be processed (converted to the natural form) by the liver to filter ethanol, thus putting additional stress on the liver already overloaded with toxins that are abound in modern environment;

·         Ethyl Ester form of the Omega-3 fish oil is not allowed in some countries with strict health regulations. For example, Ethyl Ester is not allowed for sale over the counter in Denmark and Sweden; it is expected that it will soon be prohibited in UK and Norway; the ingredient recognized as safe in Australia is specified as the "triglyceride of the Omega-3".


2.     There have been 10 frequently referenced studies comparing effectiveness of the EE form of the fish oil to that of the TG form. Half of the studies show that there is no significant difference between TG and EE form. The other half shows that the TG form is absorbed by the body significantly better than the EE (no study showed that EE is absorbed better than TG).

3.    Ethyl Ester form is less stable, more prone to oxidation, which leads to the decrease in the oil freshness, causes "fish burps", and results in the need for enteric coating. Most of the studies conclude that fish oil is best absorbed in the stomach rather than in the intestines. However, if a fish oil supplement pill is enteric coated to preserve the freshness of the ethyl ester oil, it passes through the stomach unchanged and is only broken down for digestion in the intestine.

Highly oxidized oil also places additional demands on the anti-oxidation processes and nutrients within the body; it is particularly known to deplete vitamin E levels. 



One factor in favor of Ethyl Ester form is that it may be slightly less expensive (If a molecularly distilled and concentrated Omega-3 supplement is in the triglyceride form, it is marketed as such because the triglyceride form is superior and more expensive to manufacture.  If an Omega-3 fish oil supplement is concentrated and purified and does not disclose what form it is, it is an ethyl ester).

* Except for the cell membranes: when an Omega-3 acid molecule is incorporated inside cell membranes, it is in the phospholipid, not in the triglyceride form.