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  • Writer's picture Bowie Matteson

Why Fish Oil Isn't Doing What You Think It Is

Updated: Dec 21, 2022

Fish oil, rich in omega-3 fatty acids, has been touted as a cardiovascular necessity for the better part of the last 50 years. Whether in your local pharmacy or your doctor's office, we've been taught our whole lives that fish oil is a must.

But what for? Fish oil is chock full of omega-3 fatty acids. There are claims that this type of fatty acid is good for inflammation, arthritis and cardiovascular health. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), AKA omega-3s, have been linked to altering the membrane fluidity of inflammatory cells and down-regulating the production of an inflammatory precursor, arachidonic acid.

Arachidonic acid is an omega-6 fatty acid. The difference between an omega-3 and an omega-6 being that the first double bond (there are several) occurs at either the 3rd of 6th carbon atom, respectively. Both are polyunsaturated fatty acids (PUFAs) in that they contain multiple double bonds.

When you experience trauma, like a cut, the cell membranes are broken and there's contents are spilled. The body sensing the spilled cell membranes is what leads to an inflammatory response.

So, arachidonic acid being released and oxygenated by enzymes in the body leads to the formation of an important group of inflammatory mediators, called eicosanoids. These eicosanoids are oxidized, which leads to the production of free radicals, thus causing inflammation and initiating the healing process.

Supplementing omega-3s has been found to elicit less inflammation, or a neutral response, and serves to displace arachidonic acid from the cell membrane without eliciting an inflammatory response. This in theory removes some of the fuel from the fire.

A lot of jargon, I know. But understand that the body's natural inflammatory response involves the release and oxidation of fatty acids, both omega-3s and omega-6s. Omega-3s are a weaker, less inflammatory replacement for omega-6s.


I'm here to say that the argument for supplementing omega-3s is a weak one, and actually harmful based on the production of the commercial fish oils.

So, quick recap: The body uses the oxidation of PUFAs to give off free radicals to stimulate an inflammatory response.

Our response to that? Let's use a weak PUFA for less inflammation. And what about the free radicals from omega-3s? Wouldn't those cause inflammation too? Albeit less, but surely there has to be a better way.

But really, why are we even so infatuated with fish oil? You'd think with our innovations in health and medicine that we wouldn't settle for something like replacing the problem with a not as bad problem. What's the story on how omega-3s came to be so popular?

The story is somewhat ambivalent. Nutritionally speaking, fish has been consumed for thousands of years. Mediterranean and East Asian cuisine rely heavily on fish. As an additive, garum, or fermented fish sauce, was a staple in ancient Roman and Greek cuisine. Cod liver oil was a popular remedy for rickets in English kids during the Industrial Revolution because of its vitamin D and vitamin A content.

Commercially, fish oil as we know it seems to have made its first go around as fertilizer. Fish scraps were ground up and used for it's nitrogen and trace minerals. It also had its stint in the wood varnish and paint industry. During worldwide rationing of petroleum in World War II, where the petroleum typically used in mixing and finishing paint was being reserved for fuel, fish oil was used as an economical replacement.

The DHA and EPA benefits began being touted in the 1960s and 70s, during the high carb, low fat craze stemming from President Eisenhower's heart attack in the 50s (which was somehow linked to saturated fats). Around the same time, it was also found that Inuits, with elevated levels of EPA and DHA because of their fish-rich diets, had much better cardiovascular health than typical Americans. Ergo, more EPA and DHA like the Inuits and you'll have a heart like one too. Right?

So it's eaten, heals your heart, it's fertilizer and it seals paint. As someone interested in my health, am I supposed to eat it or save it for my next wood-working project?


I started this article with the chemistry behind PUFAs because it's an essential part of truly understanding how fish oil has such versatility. The first thing to note is that PUFAs are the most unstable fatty acid. This means that they react quickly with heat and oxygen. An oxidized PUFA releases ROS and other highly reactive carbonyls. Remember the inflammation cascade? It also causes polymerization, like in paint or varnishes.

In humans:

Trauma -> release of PUFA from cell membrane -> oxidation of PUFA -> ROS -> inflammatory response

In paint:

paint or oil is applied to surface -> oxygen from air hits PUFA in paint -> polymerizes and forms coat or sheen

I've got questions: Are we accounting for these qualities of PUFAs, relating to heat and oxygen, in our preparation of fish oil? Are we tracking the oxidation of PUFAs in production so that we aren't just ingesting free radicals? Do blood vessels of those taking fish oil start to stiffen because of polymerizing PUFA oxidation?

These are important questions to ask and it seems no one in the mainstream, the American Heart Association and National Institute of Health included, is noticing.

So to answer my own question: No, we aren't really accounting for the highly reactive nature of PUFAs in production. There is no metric in place to measure the degree of oxidation for commercial fish oil.

Fish oil is the result of blended fish parts being centrifuged to remove the oil and water from the slurry. It then goes through a cleaning process that includes steps like degumming, neutralization, bleaching and washing.

And while I won't focus on how unappetizing all of that sounds, what I'm concerned with is:

A. the temperature that the fish slurry is cooked before the extraction actually takes place


B. what temperatures the things like bleaching and washing are happening at.


So how is this supposed to go, Bowie? Are we supposed to eat raw fish? Why are the benefits of cooked fish so well documented, but fish oil is blowing up the system?

The answer lies in the all too common whole food vs. supplement debacle. Whole food, when raised ethically and grown responsibly, more often than not contains nature's intended blend of nutrients. This "blend" I mention refers to the proper ratios to ensure proper usage within the body. Most supplementing bypasses the ratio and blend aspect of whole food. It is strictly computational according to the person's need for the nutrient. If A + B = C and I'm low in C, but adequate in A, I better supplement B.

Whole fish contains a plethora of supporting characters to it's omega-3s. Vitamin E, which acts to prevent oxidation of the PUFAs, as well as a sea of trace minerals like potassium and magnesium, are all found in fish. I reckon the natural blend of PUFAs and the antioxidant vitamin E is what truly results in the documented findings attributed solely to omega-3s.

-> Try Thorne's Ultimate-E to combat the accumulation of harmful PUFAs.

So the question remains: to supplement fish oil or not? Right now it's a hard no for me. Taking a compound without any regard shown for its volatility under specific circumstances is not good. And those are circumstances I know are happening in production. Not to mention you've been loading yourself with other highly oxidized PUFAs your entire life (re: canola oil, seed oils). For now I' m sticking to whole fish, and supplementing vitamin E to account for my previous PUFA history.

Does any of this sound fishy to you?

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