How to choose a good marine oil supplement

Introduction to marine oils

The reason for supplementing with marine oil is to directly obtain vital-for-health omega-3 fatty acids EPA and DHA which are in short supply in today's typical diet

•  EPA - For inflammation control, heart protection, plus so much more, by providing anti-inflammatory eicosanoids 

Understand how eicosanoids are VITAL FOR HEALTH

•  DHA - For brain and nerve function.

EFAS -FATS OF LIFE

If not eating oily fish 2- 3 times a week, then supplementation with a marine oil is recommended for EVERYONE as "preventative medicine", but is a “MUST” for:

•   Treatment of any inflammatory health problem.    Basically, this is nearly all problems. e.g. heart disease, diabetes, cancer, arthritis (aching joints/muscle stiffness), depression;

•   Those having brain-related, neurological problems.   For these people, obtaining omega-3 DHA is crucial, and other Omega-3 parent sources, such as flax seed and walnuts, can not be relied upon.

•   A woman during pregnancy;

•   Growing children

•   The elderly, to prevent osteoporosis;

•   Both a woman and a man prior to conception / A woman in mid-life or menopause

Criteria for a good marine oil supplement

Not rancid (containing minimal lipid peroxides)  i.e.  Independently tested /certified as toxin-free.  

Reputable fish and cod liver oil processors voluntarily submit their oils for independent testing to obtain a Certificate of Analysis (COA) that shows markers of rancidity and toxin levels. On request, a manufacturer should be able to provide a batch-specific COA that lists EPA and DHA content, oxidation levels (Peroxide Value <5 meq /kg), heavy metal content, and microbial presence (such as bacteria, yeast or mold).

If a marine oil is rancid, not only is it not beneficial --- it is harmful!   The long-chain EPA and DHA fatty acids are highly susceptible to oxidation by oxygen, heat, metals, and especially light.  Lipid peroxides in rancid oil promote oxidative damage in tissues and associated inflammation involved in so many of the current-day diseases / health problems.  Fish oil should not smell fishy.

Before they can be imported into the U.S., all fish oils must be tested according to the Association of Analytical Communities (AOAC) protocols and approved free of detectable levels of 32 contaminants (e.g. heavy metals, PCB's, dioxins). The European Union (E.U.) also has similar stringent testing. 

To minimize potential for contaminants, fish used for fish oil production should be low on the food chain (E.g. sardines, anchovies, skipjack tuna, smaller mackerel, but not large mackerel or Albacore tuna), biblically-recommended as "clean" (i.e. with fins and scales), and come from unpolluted waters.

Contain a sufficiency of EPA / DHA

 You are typically looking for a minimum daily maintenance intake of a combined total EPA + DHA of about 400-500 mg, which for example, is obtained with 2- 1000 mg capsules of wild Antarctic salmon oil (~180mg EPA and ~220mg DHA) .  A 1/2 tsp. dose of cod liver oil supplies about 220 mg EPA and ~300 mg DHA

Be bioavailable

Normal absorption rate of ingested fats is very efficient at about 95%.  Jones et al, 2004   Fish oils are better absorbed when consumed with fatty meals.   Lawson et al, 1988 

Studies are few, small and results are mixed regarding bioavailability between different chemical forms of marine oils.   Ethyl esters (in concentrated oils) are generally the lowest, and phospholipids (in krill oil) the highest, but overall there's not much difference between them as regards bioavailability, especially over long-term supplementation. Consumption of all forms significantly increases PLASMA EPA and DHA levels     Dyerberg et al, 2010,  Davidson et al, 2011 

These are the different chemical forms of marine oils:

•  Triglycerides (TGs). Nature's food-form of fish oil - 3 fatty acids connected to a glycerol backbone;

•  Free fatty acids (FFAs).   Not a significant presence in diet.

•  Ethyl esters (EEs).   Concentrated form - fatty acids attached to an ethanol backbone;

•  Resterified TGs (rTGs).  Concentrated form.  Ethanol backbone removed from ethyl ester and replaced with TG.

•  Phospholipids (PLs).   Krill oil is naturally 40% PLs -  two fatty acids and a phosphate group esterified to a glycerol backbone.

A word on fat digestion.    Ingested EFA fats (in the form of triglycerides. phospholipids, and free fatty acids) are hydrolized (taken apart) in the intestines to produce free fatty acids and monoglycerides. Intestinal lining cells repackage these fats back into triglycerides and phopholipids and put them into lipoprotein chylomicrons (with cholesterol) for delivery into circulation via the lymphatic system.

Fat journey in the body

Incorporation of EPA/DHA into TGs and phosphatidylcholine (PC) in the blood did not differ with  TG, rTG, FFA, or EE supplement forms.  West et al, 2016)

Metabolic effects of krill oil (phospholipid form) are essentially similar to those of fish oil but at a lower dose of EPA and DHA, in healthy volunteers.  6 krill oil capsules (N = 36; 3.0 g/day, EPA + DHA = 543 mg) or 3 fish oil capsules (N = 40; 1.8 g/day, EPA + DHA = 864 mg) daily for 7 weeks.  Ulven et al, 2011  

Preferably contain vitamins A and D (especially if you live in sunless climes).  

Vitamins A and D are naturally present in appropriately balanced amounts in natural, low-temperature-processed cod liver oil (CLO) (or other fish liver oils).   It is not uncommon that many cod liver oils on the market have gone through a molecular distillation process that removes all of the natural vitamins, including A and D. Some companies add A and D (synthetic or natural) back into the oil in various amounts / ratios.

Low heat-processed Cod (or other fish) Liver Oil

Cost effectiveness

Gram for gram, krill oil and cod liver oil capsules are comparatively more expensive than other marine oils

The three marine oil choices

(1) Cod (or other fish) liver Oil (CLO)

A good cod (or other fish) liver supplement has naturally high level of vitamins A and D and has been low /no-heat processed.  Available as liquid or capsules (expensive). Half a teaspoon of good CLO contains ~220 mg EPA and  300 mg DHA.  However, there are very few brands that meet the criteria for a good, recommendable oil.

Cod (or other fish) liver  oil (CLO) - What you need to know

(2) Fish body oil (FBO)

Fish oil contains omega-3 EPA and DHA  as triglycerides.   The TG form is naturally found in nature, preferred by many because it is the next best choice to eating fish.  The high-omega-3 content fish typically used to produce FBO are salmon, herring, mackerel, anchovies, and sardines. There are 3 different levels of processing, the natural triglyceride (TG)  form (1 g (typically 1 capsule) contains 90 mg EPA / 110 mg DHA) , ethyl ester form (purifed and concentrated up to 3 times), and reesterified TG form (ethyl ester form converted back to TG form).

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

(3) Antarctic Krill oil

From tiny shrimp-like creatures.   Boasting a high antioxidant content, to prevent rancidity.  DHA content is on the low side, but fatty acids are about 25-30% more bioavailable than in FBO. 1g Antarctic krill oil contains ~120mg EPA / ~60 mg DHA and 400 mg phospholipids.

A quality krill oil requires that it comes from a clean source (such as the Antarctic ocean) and undergoes a cold-extraction process that also protects the oil from light and air.  This is needed to prevent oxidation and to preserve its nutrients.  Avoid krill oil that has been solvent-extracted.

Antarctic krill oil for omega-3 - What you need to knowl

Krill oil vs. fish oil vs. cod liver oil

Good article: http://www.healthyfellow.com/283/krill-oil-research/

Recommendations for supplementing marine oils

Pay attention to processing methods

Choose an oil appropriately processed without damaging light, heat and air and without solvents.  Preferably packaged soon after harvesting.

Oil type

Natural krill, fish body and cod liver oils have much the same bioavailable EPA /DHA content (krill has the edge, but can cost more than the gain).   More processed, concentrated EE and rTG fish oils  contain more omega-3 in a smaller volume.

Choose cod liver oil if want to obtain some good sources of vitamins A and D.   Important if you live where the sun doesn't shine :), but also for anyone wanting to ensure the benefits of these cell-membrane protecting antioxidants.  Choose liquid CLO with "make-it-taste-better" natural flavorings for cost-effectiveness. Capsules can be triple the cost.

Recommended daily intake of EPA+DHA from fish and / or marine oil supplement  

Average maintenance dose:   ~400-500 mg of combined EPA+DHA / day (equivalent to eating at least 2 servings of oily fish per week).   About 2g /day of krill, fish body or cod liver oil   provides about 190-240 mg EPA and  120-260 mg DHA . The similar dose of concentrated oil (EE or rTG) is determined by individual product (usually ~0.6 g).

Therapeutic dose with omega-3 deficiency problems (E.g. coronary heart disease, ) intake average: 0.75 -1 gram EPA+DHA / day.  i.e. Up to double the maintenance dose (3 - 4 grams of krill, fish body or cod liver oil).  1 tsp. liquid marine oil is 4.6 grams.  Therapeutic doses in studies typically use 3 grams of marine oil /day. For those with high blood pressure, 3 grams / day of marine oil is appropriate

You can have too much omega-3, which can be detrimental.   Keep to the recommended doses.  Exceeding 900mg EPA and 600mg DHA can suppress necessary inflammatory immune system responses

A sufficient EPA / DHA intake maintains the Omega-3 Index > 8%.  

Synergistic additions

Vitamin K2.  Improves EPA /DHA bioavailability. r Weston A. Price found that something in butter oil (Activator X) aided bioavailability of cod liver oil. 60 years later, Activator X was identified as vitamin K2.

Vitamin K

Vitamin E.    A good supplement for anyone (400 IU / day of mixed tocopherols), but especially when taking marine oil. This fat-soluble antioxidant helps protect against cell / tissue damage from any peroxides formed in the marine oil.

Interactions

Marine oil supplements have the potential to interact negatively with blood-thinning medications.   E.g. warfarin (Coumadin). Omega-3 is a natural blood thinner.

References

Davidson MH, Kling D, Maki KC. (2011) Novel developments in omega-3 fatty acid-based strategies. Curr Opin Lipidol ;22:437-44. PubMed

Davidson MH, Johnson J, Rooney MW, Kyle ML, Kling DF (2012 Nov-Dec) A novel omega-3 free fatty acid formulation has dramatically improved bioavailability during a low-fat diet compared with omega-3-acid ethyl esters: the ECLIPSE (Epanova(®) compared to Lovaza(®) in a pharmacokinetic single-dose evaluation) study. J Clin Lipidol. PubMed

Dyerberg J, et al. (2010 Sep) Bioavailability of marine n-3 fatty acid formulations. Prostaglandins Leukot Essent Fatty Acids ;83(3):137-141. 3.3g EPA/DHA daily for 2 weeks. PubMed

Jones PJH, Rideout T.  (2014) Lipids, sterols, and their metabolites. In: Ross AC, Caballero B, Cousins RJ, Tucker KL, Ziegler TR, eds. Modern Nutrition in Health and Disease. 11th ed. Baltimore, MD: Lippincott Williams & Wilkins;

Lawson Larry D, Hughes Bronwyn G. (1988 Oct) Absorption of eicosapentaenoic acid and docosahexaenoic acid from fish oil triacylglycerols or fish oil ethyl esters co-ingested with a high-fat meal. Biochem and Biophys Res Comm Vol 156, Iss 2: 960-963 PubMed

Ulven SM, Kirkhus B, Lamglait A, Basu S, Elind E, Haider T, Berge K, Vik H, Pedersen JI (2011) Metabolic effects of krill oil are essentially similar to those of fish oil but at lower dose of EPA and DHA, in healthy volunteers. Lipids. 46: 37-46.  PubMed

West AL, Burdge GC, Calder PC  (2016 Sep) Lipid structure does not modify incorporation of EPA and DHA into blood lipids in healthy adults: a randomised-controlled trial. Br J Nutr.116(5):788-97. Epub 2016 Jul 18. PubMed