Doug Cook RD
Nutrition Demystified. Health Exemplified
Nutrition advice that makes sense. Separating hype from reality.

My experience & experiment with fermented cod liver oil – sounds nasty right?

For those old enough to remember having to take a spoonful of cod liver oil, before the of fortification of milk with vitamin D, as a way of preventing rickets, the idea of voluntarily taking it again would probably make them gag.

Cod liver oil’s rise to fame

As far back as 1799, European physicians used cod liver oil to treat the classic vitamin D deficiency disease: rickets, although at that time, they didn’t know exactly what it was they were treating [the exact cause of rickets], nor did they understand what specifically it was about cod liver oil that had such a profound positive impact on overall health.

In 1930s North America, the recommendation for a daily teaspoon of cod liver oil became one of the most important and despised [insert yucky taste!] public health policies; rickets was essentially eradicated (although it has re-emerged in the UK, US, Canada and other Western societies as vitamin D deficiency returns with a campaign of fear and advice to avoid the sun, a move that started in the 1970s).

Cod liver oil, what’s old is back in vogue

With the fortification of milk with vitamin D, cod liver oil fell out of fashion and with good reason, it tasted like crap and drinking milk was much easier. Milk was promoted largely as a way of ensuring children got enough vitamin D to prevent rickets (note however that 2 glasses a day will ensure straight bones, but not dense bones, nor is it enough to reduce bone loss in adults).

Like many things in the world of nutrition, extremes lead to extremes and a once super nutritious food was soon forgotten; very few people continued to take cod liver oil. For those of whom who do, what you’re most likely taking today is not your grandmothers’ cod liver oil.

Nowadays cod liver oils are refined, bleached to remove colour substances and sediment, deodorized by molecular distillation (heating the oil to 250C for 6 hours under a vacuum) all in the name of producing a clear, sediment-free, odourless oil that is more palatable. Sadly, this processing destroys, and removes, many of the unsaturated fatty acids (including EPA & DHA), vitamins A, B12, D, E, K2, and the quinones.

It’s true that synthetic versions of vitamin A and D are added back but not in amounts, forms or proportions that would be found naturally, nor does modern cod liver oil contain the numerous other co-factors that whole-food based oils do: scientific reductionism as its best.

Traditionally prepared cod liver oil was fermented, not unlike sauerkraut, kimchi, natto, tempeh or miso, and Green Pasture’s Fermented Cod Liver Oil takes an ‘old world’ approach to its product. It is naturally produced, unheated, high-vitamin cod liver oil that is lacto-fermented using a filtering process that retains the natural vitamins, enzymes, quinones and other co-factors.

For years, the medical community and other health professionals had warned people away from cod liver oil citing risk of toxicity from getting too much vitamin A and D; something that never seemed to be a problem in the past when it was used by thousands of people throughout North America and Europe nor substantiated in the literature today.

Many health conscious consumers are rediscovering the benefits of this traditional food and I was curious to give it a try.

So, cut to the chase, what did I think of it?

The oil comes with a syringe, allowing for a precise amount of oil to be drawn, from 1 to 5ml. My first time taking it was met with trepidation; it was dark and murky in appearance as I drew the oil from the dark brown bottle (not winning points for sure). I then added it to a bottle of strawberry flavoured Bio-K+, the smell was unmistakable, it smelled just like what you’d expected fermented fish liver oil to smell like (use your imagination). A couple of good shakes, and I put it back like a shot of tequila.

There was a residual fishy taste, there’s no getting away from it. I’ve since refined my method by adding a sprinkle of cinnamon to a base of Bio-K+ or a small amount of a yogurt drink and then chase it with a swig of coffee. I cannot take it as suggested, in water or with juice, I need something with more flavour and with a thicker consistency to help keep the oil blended.

Why do I bother?

I can pretty much eat or drink anything if I know it is ‘good for me’. Fermented high-vitamin cod liver oil is nutrient-dense and arguably the first true superfood. It provides about 10,000 IU of natural vitamin A (lacto-fermentation transforms natural vitamin A into different metabolites and co-factors for easy absorption, it contains at least 15 different natural forms of vitamin A), 2000IU of vitamin D, vitamin K2 (an important vitamin that is lacking in today’s modern diet because traditional farming practices have been replaced with inferior methods, and because once traditional foods have been deemed as unhealthy – see post here), vitamin E, 700mg of EPA, 300mg of DHA per 5ml (1 teaspoon).

A word on vitamin A

For eons humans got lots of pre-formed vitamin A by consuming vitamin-A rich foods like beef, fish, chicken, and goose livers, eggs, and giblets. Vitamin A (i.e. retinol) is not the same thing as beta-carotene, although the body can convert beta-carotene (albeit not that well, certainly not as well as once thought) to vitamin A. Vitamin A, like vitamin D, is converted to a hormone called retinoic acid whose role in human health include:

  • mineral metabolism, including calcium, phosphorus and magnesium which aids in the formation and maintenance of bone and teeth
  • normal growth (in infants & children)
  • successful reproduction
  • healthy skin
  • optimal immunity
  • vision
  • maintenance of mucous membranes
  • prevention of dryness of the conjunctiva and cornea, a.k.a. ‘dry eye’

It’s the last one that struck me the most. Something I knew from undergrad, but had forgotten about, and it didn’t dawn on me that I might be lacking in vitamin A as I suffered from dry eye, routinely needing artificial tears to lubricate my eyes, especially first thing in the morning. I had addressed the usual suspects including getting enough omega-3 fats. After starting the cod liver oil, my dry eye was all but eliminated. Given vitamin A’s role in immunity, I look forward to seeing how it, along with my more than adequate vitamin D level, keeps me free of colds and/or the flu!

It’s best to get natural forms of vitamin A rather than the synthetic versions in most standard supplements, try to include eggs, and liver, if you’re like me and gag at the very thought of pan fried liver, try a good quality liver pate, or….fermented cod liver oil!