Fish body oil (FBO) for omega-3 EPA / DHA - What you need to know

Overview

Oils from the body of a fish are a natural dietary source of the vitally necessary omega-3 fatty acids EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) .   EPA is needed to counter inflammatory eicosanoids from omega-6 fats, and DHA (a metabolite of EPA, or obtained directly) is needed for brain and nerve function. These can be obtained in quantity by eating oily fish, grass-fed animal brains, testes, eyes, and/or  red/brown algae, or by taking a marine oil supplement.

EFA CHART of conversions and effects

Choose oil from WILD fish and third-party tested for contaminants

Many of our seas, lakes and rivers are sadly contaminated by industrialization.   Oil extracted from fish in contaminated waters therefore require processing to remove contaminants.

Thankfully there are still a few water bodies in the world that are not contaminated to a concerning level.   These include the Antarctic (Southern) ocean and the Norwegian sea.  Fish from these areas may not need detoxifying to any great length, but should be tested for purity,  since there are no guarantees. A legitimate manufacturer should be able to provide a batch-specific Certificate of Analysis (COA), listing EPA/DHA content Peroxide Value (level of oxidation / rancidity), heavy metals (mercury) and microbial presence (E.g. E.coli, staph, salmonella, yeast, and mold). Look for the high standard European EuroFins- or IFOS-compliant oils.  

Farm-raised fish in certain areas (E.g. from Chile) are given very high levels of antibiotics to stave off infection.    All farm-raised fish are given some level of antibiotics in their feed to counter infections introduced by the overcrowded conditions in net pens.

Farm-raised fish have an unnatural omega-6 rich diet.   Now typically ~70% vegetable protein, such as soybean and corn (which are also GMOs).  Their former diet consisted of more omega-3-rich fishmeal than they are getting nowadays.

There are 3 different types of fish oil

(1)  Non-concentrated, natural triglycerides (TGs);  (E.g. Pure Alaska Omega Wild Salmon Oil)

(2)  Concentrated ethyl ester (EEs) - "Fish oil concentrate"  (E.g. Wiley's Wild Alaskan FIsh Oil)

(3) Concentrated re-esterified triglycerides (rTGs)

Typical commercial processing method for marine oils

(1) Non-concentrated, natural triglycerides (TGs)

Fish oil is COLD-pressed from fish body flesh or livers.   Cold-pressed means the extraction process is done at a temperature under 140°F.   Some people prefer the unprocessed, natural TG supplement form, since it is the next best thing to eating fish.

Non-concentrated fish body oil is inherently in nature's bioavailable triglyceride (TG) form.    The TG form is somewhat more bioavailable than processed/concentrated ethyl-ester (EE) forms of fish oil. 

EPA / DHA content / ratio in non-concentrated FBO is what nature determined it to be.   Depending on the fish, natural FBOs provide a maximum of 90mg EPA / 110mg DHA per 1,000 mg of oil (i.e. 30% potency). E.g. 2-1000mg wild salmon oil capsules contains ~180mg EPA / 220 mg DHA.  (for comparison, a 4oz portion of salmon averages about 1 gram of EPA/DHA).

May contain toxins if not from a clean ocean source.   If you buy cold-pressed, unpurified fish oil, ensure that it is independently certified.

(2) Ethyl Ester (EE) - "Fish oil concentrate"

Natural TG oil is typically molecularly distilled at lower-than-usual temperatures to concentrate EPA/DHA  2- 3x.   In a process called trans-esterification, the glycerol backbone is removed from the oil's fatty acids and an ethanol molecule is attached to each of the now free fatty acids (FFAs). This process occurs naturally in the body after digestion. The created ethyl ester (EE) allows for molecular distillation at lower temperatures than usual, creating EPA and DHA concentration levels greater than naturally found in fish.  Optimal results that retain omega-3 integrity and do not introduce trans fatty acids are obtained by using 2 stages of distillation, the first at 249F and the second at 284F.   Rossi et al, 2011  Other methods of concentrating fish oil are enzymatic processing or CO2 extraction.

Bioavailability of EPA+DHA  of ethyl esters is a little less than that of TG-form fish oil.  i.e. one would need a little more to obtain the same amount of omega-3. One study found EE form to be ~three quarters less bioavailable than TG form, meaning you would need 1.5 times the amount for equivalent dose.  Dyerberg et al, 2010

(3) Re-Esterified Triglyceride (rTG)

rTGs are synthetically created when ethyl esters are freed from their attached ethanol groups and rebound to a glycerol backbone.  rTGs retain the same potency and fatty acid ratios of their EE counterparts. However, they are not identical - the original position of the triglyceride's carbon bonds change and the molecule's overall structure is altered.

Bioavailability of EPA+DHA  from concentrated re-esterified triglycerides was found in one study to be 1 ¼ times that of natural fish oil. Dyerberg et al, 2010

Recommended brands of fish body oil
Brand	Form		Maint. level serving EPA / DHA	Maint. level Serving Cost (as of Feb 2020)			Independently  tested by:
				Seller	/day	/month
Pure Alaska Omega Wild Salmon Oil www.purealaskaomega.com •  Cold-pressed, Extra virgin extraction process • Wild caught	TG		180 mg EPA  /220 mg DHA (2 -1200mg caps)	Costco Samsclub Amazon	20c 20c 26c	$6 $6 $7.80	3rd party. Enter your batch#
Kirkland Signature Wild Salmon Oil •  Cold-pressed, Extra virgin extraction process • Wild caught • Enteric coating helps prevent fishy aftertaste	TG		180 mg EPA  /220 mg DHA (2 -1200mg caps)	Amazon	~21c	$6.35	IVO
Wiley's Wild Alaskan Fish Oil • Wild caught • Contains 2000 IU D3, 80ug K2 • Non-solvent extracted process	EE		375 mg EPA /125 mg DHA (1- 500 mg cap.)	Amazon	$1.06	$32	3rd party