Download Fermented Cod Liver Oil - Green Pasture Products

There is a lot of controversy and confusion about cod liver oil. Alison Birks, MS, AHG, CNS is a nutritionist
and researcher who has looked into the issue of cod liver oil, fermented and otherwise. She has written an
article for us that I have found very helpful in clarifying the confusion. We hope you will find it interesting
and useful. - Ron Schmid, ND
Fermented Cod Liver Oil: A Traditional Food
By Alison Birks, MS AHG, CNS
Is fermented cod liver oil (CLO) a health food? Can fermented CLO provide crucial nutrients in a manner
compatible with traditional diets? Or is fermented CLO (as some critics claim), an invention that is based
on a myth? Is it marketing hype, or worse--- is fermented CLO a putrid by-product of the “rotting
process”? In defense of fermented CLO, let’s take a look at the facts.
Fermented cod liver oil is a natural product that is made by the prolonged soaking of wild cod livers in
brine, allowing the liver to naturally ferment, then draining off the resulting oil that accumulates on the
top. Fermentation is an ancient practice that has been used worldwide to adequately preserve food
(including meat and fish) when other methods of preservation have failed.
Submerged Culture Fermentation
The process of preparing cod liver oil by fermentation is similar to that used in traditional Thai cuisine to
produce fish sauce (Nam phrik) and fish paste (Kaengtai pla). This fermentation method is also known
as submerged culture fermentation (SCF), which is defined as “fermentation under conditions of high
moisture content”. Salt tolerant, lactic-acid producing bacteria (LAB) ferment the fish and yield various
components in the final product. In a likewise fashion, cod liver fermentation yields the following: liver
glycogen is broken down by microorganisms to yield lactic acid (which acts to further preserve the food
product); proteins are degraded into free amino acids as well as biogenic amines and various flavor/
aroma compounds; fats are broken down into free fatty acids, and these can be further oxidized into
other flavor/ aroma compounds. Please note that while it is true that fats are not technically highly
fermented, the other components present in the cod liver ARE capable of being fully fermented, and this
allows the oil to be liberated from the livers with the added benefit of enhanced vitamin content and
the breakdown of toxic substances during fermentation.
Table I: Summary of Cod Liver Fermentation Products
LIVER (Glycolysis)-------Glycogen----------- Lactic Acid, Other Organic Acids
LIVER (Lipolysis)------Fats------------------ Free Fatty Acids, Flavor & Aroma Compounds
LIVER (Decarboxylation)------Proteins-------------- Peptides & Free Amino Acids , Biogenic Amines,
Flavor & Aroma Compounds
Enhanced Vitamin Content, Natural Forms of Vitamins
In general, the process of fermentation enhances the nutrient composition of the final product. For
example, in a comparison study of fermented versus non-fermented garlic, fermented garlic was shown
to contain more vitamin E, B2, and amino acids than an unfermented form. Fermentation also increased
the important antioxidant SOD (Superoxide dismutase) enzyme activity of garlic by more than 13 times
that of the unfermented form.
Fermentation of cod liver oil may result in dramatically increased vitamin content, although the amount
of each vitamin present in each batch is highly variable. Some of the naturally occurring nutrients that
are enhanced during this process include the fat-soluble vitamins A, D and K. Non-essential nutrients
such as non-vitamin K Quinone’s may also be increased. Because the fermentation processing method
naturally increases the vitamin content of the oil, no synthetic antioxidants are added to the oil.
Numerous studies have shown that synthetic vitamins do not act the same way in the body as naturally
occurring forms, and may even pose an unnecessary health risk. For this reason, many consumers are
looking for a completely natural product without added synthetic vitamins. Fermented cod liver oil is
free of synthetic vitamins that many find objectionable.
Natural Fats: Enhanced Bioavailability
In the process of cod liver fermentation, it is likely that the resulting oil exists in both natural triglyceride
and in free fatty acid form. Significantly, both intact triglyceride and free fatty acid forms are equally
well absorbed and are highly bioavailable to the human body. Both of these natural forms are superior
to synthetic ethyl ester forms. The ethyl ester form is made by reacting free fatty acids with ethanol
(alcohol) in order to concentrate the EPA and DHA to levels greater than that found naturally in fish.
This process is called molecular distillation and the resulting product is completely synthetic. Please
note that most of the commercially available fish oil, including CLO, is the synthetic EE form. Fermented
CLO provides a natural form of important omega-3 fatty acids.
Reduced Toxicity
In general, the process of fermentation has been shown to reduce toxic components in food. In one
dramatic example, a recent study showed that the deadly nerve toxin in “fugu” or puffer fish,
(terodotoxin) was virtually eliminated by traditional methods of food preparation such as prolonged
fermentation, and that it yielded a non-toxic, edible food product. It is also well established that antinutrients in plant foods are degraded during fermentation. Based on these assumptions, fermented CLO
quite possibly may have less naturally present toxins than other forms of CLO.
Drawbacks
Fermented CLO may exhibit natural variation in its metabolites and cofactors, including variation in the
amount of vitamins it contains. For this reason, fermented CLO may contain extremely high quantities
of fat-soluble vitamins such as vitamins A and D. It may also contain flavors and aromas that some may
consider to be unpleasant, although these are not likely to be toxins, as toxic substances are generally
reduced during the fermentative process. Due to the increase in lactic and other organic acids
produced during fermentation, some people may find this tart taste objectionable. Lactic acid is not
harmful, but is a natural occurrence in fermented food products such as yogurt, kefir, sauerkraut, etc.
However, to suggest that fermented cod liver oil is “putrid”, to liken the fermentation process to
“putrefaction” or the “rotting process” shows ignorance about the entire process of lactic-acid
fermentation. Lactic-acid fermentation of food products, especially meat/fish, exists for the express
purpose of eliminating putrefactive, anaerobic, and pathogenic microorganisms.
Putrefaction versus Fermentation
Putrefaction or “rotting” is very different from lactic acid fermentation. The formation of putrescine
and cadaverine are biomarkers for incomplete lactic acid fermentation. Both are foul -smelling, toxic
biogenic amines produced during putrefaction. Cadaverine is a breakdown product of the amino acid
lysine, while putrescine derives from the amino acid ornithine. Both are components formed during
decomposition of the proteins in rotting meats through anaerobic bacterial action. Interestingly, small
traces of these compounds are often present in fermented meat products and contribute to the overall
flavor profile without causing any harm to human health. Some individuals are intolerant of even trace
amounts of biogenic amines in the diet and need to restrict intake. Many factors can affect the
formation of biogenic amines, and the process needs to be tightly controlled. A quality manufacturing
facility can optimize the environmental conditions to allow only beneficial microorganisms to thrive, and
for complete fermentation to occur. According to Dave Wetzel of Green Pasture, Green Pasture
Fermented CLO has repeatedly tested free of undesirable biogenic amines such as putrescine and
cadaverine.
Table II provides a summary of the factors, which affect the formation of biogenic amines during meat
fermentation.
Table II: Factors Affecting Biogenic Amine Formation During Fermentation
1.
2.
3.
4.
5.
6.
Microbial cultures present
pH
Salinity
Size or Diameter of Fermenting Meat Product
Sanitation
Processing / Storage of Raw Materials
Summary
Fermented cod liver oil is a traditional food that delivers natural forms of important fat soluble vitamins,
such as vitamins A, D and K. The fermentation process enhances the nutrient content, which can vary
widely from batch to batch. FCLO also provides essential omega-3 fats in their most bioavailable forms.
It is likely that FCLO is naturally lower in toxins, although it may contain traces of biogenic amines, which
can be problematic for certain sensitive individuals.
References
Vitamin Content and Amino Acid Composition of Pickled Garlic Processed With and Without
Fermentation, A. Montano et.al., J Agric Food Chem., 2004. 52 (24) pp 7324-7330.
Increased Anti-Oxidative Potency of Garlic by Spontaneous Short-term Fermentation, Emiko Sato et.al.,
Plant Foods for Human Nutrition, 61: 157-160, 2006.
Fermented Meat Products: Organoleptic Qualities and Biogenic Amines—A Review, V.P. Singh, et.al.,
American Journal of Food Technology, 2012, pp. 1-11.
Bacterial Diversity and Functionalities in Food Fermentations, Frederic Ravyts et.al., Eng. Life Sci. 201, 12,
No. 4, 356-367.
The Role of Lactic Acid Bacteria in Safety and Flavour Development of Meat and Meat Products, Lothar
Krockel, Chapter 5, Lactic Acid Bacteria-R& D for Food, Health and Livestock Purposes,
http://dx.doi.org/10.5772/51117.
“Fermented Fish Products”, Application of Biotechnology to Traditional Fermented Foods, 1992, p. 133
Dave Wetzel, Green Pasture, personal communication
Removal of Toxin (tetrodotoxin) From Puffer Ovary by Traditional Fermentation, Anraku K et.al., Toxins,
2013, Jan 18: 5 (1): 193-202.
Bioavailability of Marine n-3 Fatty Acid Formulations, J Dyerberg, et.al., Prostagalndins Leukot.
Essent. Fatty Acids. 2010 Sept; 83 (3): 137-41.