Cod liver oil is, to be blunt, poisonous trash.

Yes, I took it in the past.

Yes, I fell for the “traditional food” story too.

Then I looked at the research.

What did I find?

Dead animals.

Sterile animals.

Paralyzed animals.

Heart damage.

Liver necrosis.

Immune suppression.

Lower bone density.

More asthma.

Oxidized fatty acids that become toxic aldehydes.

Persistent organic pollutants (aka POPs, which include DDT and PCBs) concentrating in fish oils—especially cod liver oil.

And, best of all, repeated warnings from Weston A. Price himself that cod liver oil could be toxic, injurious, and structurally damaging.

Somehow, that part of the “ancestral wisdom” story never seems to make it onto the label.

If you would rather watch me go through this entire pile of research on video, here it is:

This article is the written version.

We are going to beat the heck out of this subject.

But Cod Liver Oil Is “Natural”!

So is lead.

So is mercury.

So is arsenic.

So is a dead fish liver rotting in a barrel.

“Natural” does not mean safe, nutritious, or appropriate for daily human consumption. Assuming that it does is the appeal-to-nature fallacy.

People hear:

Wild-caught.

Raw.

Virgin.

Traditional.

Fermented.

Then their brains turn off.

The liver is a detoxification and storage organ. Cod liver oil is the fat squeezed or separated from that organ.

I call it toxic fish fatty-liver juice.

Sounds delicious, right?

The real questions are:

What accumulated in the fish?

What accumulated in its liver?

What happens when its extremely unstable fatty acids are removed from the fish, processed, bottled, stored, opened, exposed to air, maybe even purposely exposed to light, and then swallowed?

What happens when those fatty acids oxidize inside the human body? Because they will, and they do.

And what actually happened when researchers fed this stuff to animals?

Let’s find out.

Cod Liver Oil Poisoned Animals Long Before Influencers Called It a Superfood

An older scientific review titled *Biological Activities of and Requirements for Polyunsaturated Acids* summarized the early cod liver oil literature.

The authors wrote:

“Investigations of excessive doses of cod liver oil suggested it to be poisonous. A voluminous literature developed largely in Scandinavia.”

A voluminous literature.

Not one confused researcher.

Not one bad batch.

Not one internet anecdote.

A voluminous literature.

What did investigators report in animals given cod liver oil?

· suppressed growth;

· leukopenia, meaning reduced white blood cells;

· hemorrhage of the heart;

· degeneration of heart muscle;

· pulmonary edema;

· and liver necrosis.

Liver necrosis means the liver tissue was dying.

From a supposed health food?!?

The same review described cod liver oil poisoning cattle, producing stiffness and muscle lesions. In calves, the toxicity appeared as severe muscular dystrophy. Similar injuries were reported in other herbivores.

And here is where the excuse-making gets interesting.

Researchers tried blaming the damage on vitamin deficiency.

They tried blaming it on hypervitaminosis.

They tried explaining it away with other features of the diet.

Yet investigators kept tracing the problem back to the oil, the unsaturated fatty acids, and the lipid (fat) peroxides produced as those fatty acids oxidized.

So which part of cod liver oil is the problem?

The “vitamin” A?

The vitamin D?

The highly unstable PUFAs?

The oxidation products?

Yes.

Growth Retardation, Diarrhea, Smaller Testes, and Sterility

The same paper summarized growth retardation and diarrhea caused by cod liver oil, tuna oil, sardine oil, and menhaden oil (menhaden are small Atlantic fish of the herring family).

Wait.

Fish oils caused growth retardation and diarrhea?

Yes.

What helped relieve those effects in one experiment?

Cottonseed oil.

The dreaded seed oil helped relieve the damage caused by the sacred fish oils.

That’s awkward.

Then we get to the male rats.

Rats receiving a diet containing 2 percent cod liver oil had testes averaging 0.68 percent of body weight. Rats receiving the dreaded soybean oil had testes averaging 0.98 percent.

Smaller testes in the cod-liver-oil group than the literally phytoestrogen-filled soybean oil group.

But wait. It gets better.

The cod-liver-oil-fed rats were sterile.

Sterile.

Maybe somebody should tell the “fertility nutrition” crowd.

What Happened After We Started Giving This Stuff to Babies?

Now look at the allergy pattern.

The paper *Introduction of oral vitamin D supplementation and the rise of the allergy pandemic* traced a very interesting timeline.

Around 1880:

Rickets was common in English cities.

Commercial cod liver oil production was beginning.

Allergic disease was nearly absent.

By 1930:

Hay fever had reached about 3 percent in English-speaking countries where cod liver oil was preferentially used against rickets.

By 1980:

Vitamin D was being added broadly to industrial baby foods.

Allergy prevalence had reached roughly 30 percent.

Within a 100 year span, allergy prevalence went from:

Nearly zero.

Then 3 percent.

Then 30 percent.

That historical timeline demonstrates that the allergy epidemic is NOT a genetic problem…it’s one of accumulated toxicity induced by what people were taking.

So let’s look at studies that followed actual children.

Vitamin D in Infancy, More Allergies 30 years LATER

The Northern Finland Birth Cohort of 1966 recorded vitamin D supplementation during the first year of life and then examined allergic outcomes decades later.

What happened?

At age 31, atopy (the so-called “genetic” tendency to develop allergic diseases) and allergic rhinitis were more common among those who had received vitamin D regularly during their first year of life.

A similar association appeared for asthma.

The associations remained after adjustment for a wide range of behavioral and social factors.

The researchers concluded:

“We observed an association between vitamin D supplementation in infancy and an increased risk of atopy and allergic rhinitis later in life.”

Vitamin D during the first year.

More allergies at age 31.

Thirty years later.

There it is.

Do you understand why “I stopped taking that years ago” does not automatically mean the problem disappeared?

These substances store.

The damage accumulates.

The consequences can appear or continue decades later.

This is not genetics, as I demonstrated above. This is a society-wide poisoning.

Cod Liver Oil and Childhood Allergic Sensitization

Another paper, *Effects of early intake of fruit or vegetables in relation to later asthma and allergic sensitization in school-age children*, found that allergic sensitization at school age appeared to increase with extra vitamin and cod liver oil supplements taken during their first year of life.

A Swedish prospective study asked the question directly: *Does vitamin D intake during infancy promote the development of atopic allergy?*

Atopic manifestations were more prevalent among the six-year-old children whose vitamin D3 intake during their first year of life had been higher.

Then there is the older clinical paper *Cod Liver Oil Sensitivity in Children*.

Children repeatedly developed eczema, diarrhea, vomiting, and other reactions after cod liver oil.

The oil was removed.

They improved.

It was given again.

The symptoms returned.

What do we call that?

Patterns. Evidence.

Yet adults were forcing children to swallow it because they had been told the oil was “good for them.”

The children gagged.

They vomited.

They regurgitated it.

They developed rashes and diarrhea.

And the adults kept pushing.

Weston Price himself suggested that children’s rebellion against cod liver oil could be a reaction of self-preservation.

The children understood the situation better than the adults.

For the larger (aka worldwide) childhood liver storage and toxicity patterns, see my related video here:

Cod Liver Oil and Adult-Onset Asthma

Maybe this is only a childhood problem?

Nope.

The population-based HUNT study followed 17,528 Norwegian adults without asthma at baseline.

Cod liver oil use was associated with new-onset asthma.

Adjusted odds ratio: 1.62.

The association appeared across age groups, men and women, people with and without a family history of asthma, and different BMI groups.

The authors concluded:

“Intake of cod liver oil with a high vitamin A content was significantly associated with increased incidence of adult-onset asthma.”

High-vitamin cod liver oil.

Increased adult-onset asthma.

Maybe “high-vitamin” is not the selling point people think it is.

Childhood Cod Liver Oil, Worse Bones Decades Later

The Nord-Trøndelag Health Study examined childhood cod liver oil intake and adult bone mineral density in 3,000 peri- and postmenopausal women.

Women who reported no childhood cod liver oil had significantly higher forearm bone mineral density (BMD).

Women who reported using cod liver oil throughout childhood had 2.3 times the odds of low bone mineral density.

The researchers adjusted for body mass index, smoking, menopausal status, estrogen use, and current milk consumption.

The pattern remained.

They also saw indications of a negative dose-response relationship.

More cod liver oil in childhood.

Lower bone density later.

What had Norway recently done to commercial cod liver oil?

Reduced its vitamin A content by 75 percent.

Why reduce the “high-vitamin” content by 75 percent?

Because the old high concentration was a plausible explanation for the bone damage.

There it is again.

Arthritis and Immune Suppression

The EPIC-Norfolk cohort study found that women reporting arthritis had 60 percent higher odds of using cod liver oil. A similar pattern appeared in men.

Because this study was cross-sectional, it cannot prove whether cod liver oil helped create the arthritis or whether people with arthritis were simply more likely to take it.

What it definitely does not show is a brilliantly healthy group of cod liver oil users protected from degeneration.

Then we get to the immune system.

In a controlled human trial, fish oil decreased T-lymphocyte proliferation in healthy older people.

How much?

Up to 65 percent.

Nearly two-thirds.

Four weeks after supplementation stopped, the decrease had only partly reversed.

People love talking about “boosting” the immune system.

I prefer thinking of immune cells as part of the body’s garbage collection and cleanup system.

What happens if you disable (poison) the garbage trucks?

The trash does not disappear.

It piles up.

Fish oil did not “support immunity” in this experiment.

It suppressed immune-cell proliferation.

Weston Price’s Own Cod Liver Oil Warnings

Now we get to the fun part.

People invoke Weston Price as if saying his name ends the discussion.

“Weston Price used cod liver oil!”

Okay.

Did you read what Weston Price actually wrote about cod liver oil?

Apparently not.

Animal Paralysis at Doses Comparable to Those Advocated for Children

In *Control of Dental Caries and Some Associated Degenerative Processes Through Reinforcement of the Diet with Special Activators*, Price showed a chicken and rabbit partially paralyzed by cod liver oil.

The quantity relative to body weight was approximately what was often advocated for children.

For children.

Price wrote:

“I have seen much evidence of toxic disturbance resulting from the administration of cod liver oil and other oils.”

Much evidence.

Toxic disturbance.

His words.

Price discussed muscle degeneration, edema, paralysis, and toxic compounds whose clinical effects could be “severe and striking.”

Then he described mothers who tried to follow the directions on cod liver oil bottles.

The children fought them.

The children regurgitated the oil when it was forced down.

Price wrote that their rebellion:

“may have been in part a reaction of self-preservation.”

Self-preservation.

He then warned that forcing such a toxic product into children could be “very injurious.”

The child rejects the oil.

The child vomits the oil.

The child develops symptoms from the oil.

The adult decides the child is simply being difficult.

Brilliant.

Price Said Cod Liver Oil “Probably Often” Contains Undesirable Substances

Price summarized experiments using cod liver oils with different free-fatty-acid contents.

Among chickens receiving the lower-free-fatty-acid oils, death rates were 10 and 14 per 100.

With the higher-free-fatty-acid oils?

40 and 28 per 100.

Surviving birds were listless. Their pigmentation was abnormal. Price described them as undesirable subjects for further experimentation.

His conclusion included this line:

“Cod liver oil may contain and probably often does contain substances which are undesirable.”

Probably often.

Not “only when a dishonest competitor makes a bad batch.”

Not “only if you buy the cheap stuff.”

Probably often.

“Over-Activation” Made Cod Liver Oil Injurious

In *The Relation of Light to Life and Health*, Price wrote:

“Over-activation of cod liver oil makes an injurious product.”

What was this “activation” process doing?

Exposing the oil to light.

What happens when highly unsaturated fish oil is exposed to light and/or air?

It oxidizes.

Price was trying to find the magical amount of exposure that produced the effects he wanted without making the oil too injurious.

Too little?

Different result.

Too much?

Toxic.

This is not a stable, forgiving whole food.

It is an oxidation experiment.

More Dead Chickens

In *Newer Knowledge of Calcium Metabolism in Health and Disease*, Price described groups of chickens receiving raw and light-treated cod liver oil.

Some groups lost most of their birds.

One group receiving raw cod liver oil lost four of seven, and the survivors had retarded growth.

Another group all died.

Another lost five of six.

Another lost four of six, with delayed growth and “little spirit” among the survivors.

All chicks receiving an “overactive” product died.

This is health food?!?

Price wrote:

“This is particularly important because of the harm that will be done by ignorance in undertaking to activate preparations for practical use.”

He experimented on himself too.

A few drops of cod liver oil exposed to ultraviolet light for half an hour produced severe headaches.

A few drops.

Price warned that exposure for one hour to the summer sun or an ultraviolet lamp created a product that was “distinctly harmful.”

Then came this warning:

“Too much emphasis cannot be placed on the urgent necessity that the mistake shall not be made of putting this in the hands of indifferent or careless persons who will not watch the time carefully.”

What could be more reassuring than a “health food” that becomes distinctly harmful if somebody does not time its light exposure correctly?

Price Warned His Own Family About “Toxic Effects That Often Develop”

A transcript of a letter attributed to Weston Price around 1934 contains a warning later printed on page 391 of *Nourishing Traditions*:

“Cod liver oil can be given in moderate doses without injury and to great advantage. Seldom, however, should the child be given more than one teaspoonful a day for extended periods because of toxic effects that often develop.”

Without injury?

Because toxic effects often develop?

Often? (!!!)

The Weston A. Price Foundation’s flagship cookbook printed this warning.

Yet how many people in that world have been encouraged to take tablespoons of the stuff?

How many parents were told to give it to children every day?

How many were told that worsening symptoms were “healing” or “detox”?

Weston Price warned his own family that toxic effects often developed.

Why do his modern followers not emphasize the same warning?

Price Also Warned About Heart and Kidney Damage

In *Nutrition and Physical Degeneration*, Price warned that excessive fish oil could cause depression and that air exposure could generate toxic substances.

He wrote:

“My work and that of others with experimental animals has demonstrated that paralysis can be produced readily by overdosing. Serious structural damage can be done to heart and kidneys.”

Paralysis.

Heart damage.

Kidney damage.

Price also said overdosing with cod liver oil and other fish oils could be “definitely detrimental.”

He recommended storing the oil in small containers to limit oxidation after opening.

So no, questioning cod liver oil does not mean I failed to understand Weston Price.

It means I read more of Weston Price than the people selling his name.

Cod Liver Oil Combines “vitamin” A, Rat Poison Vitamin D, and Unstable PUFAs

Cod liver oil contains “vitamin” A and vitamin D in amounts that vary by fish, batch, processing method, and product.

Both can disturb calcium regulation.

Vitamin D3 by mouth increases calcium absorption, whether through the gut OR through bone resorption (literally pulling calcium out of bones).

“Vitamin” A pulls calcium from bones and causes osteoporosis.

Then the body has to keep blood calcium within a narrow range because excessive calcium interferes with the brain, heart, and other critical systems.

Where does the extra calcium in the blood go then?

Soft tissues.

Blood vessels.

Kidneys.

Joints.

Eyes.

Anywhere the body can shove it to keep the blood alive.

An editorial on hypercalcemia and metastatic calcification described vitamin D overload and prolonged release from fat stores after discontinuation.

One woman took the “Viking mixture” of cod liver oil and milk.

How long did she require treatment for hypercalcemia after the vitamin D was stopped?

Twenty-one months.

Another elderly woman still had elevated vitamin D markers 17 months later.

But sure. Take it every day because it is “natural.”

Fish Liver Oils Can Deliver Enormous “Vitamin” A Doses

PubChem identifies cod liver oil as oil obtained from cod livers and a source of vitamins A and D.

Marine liver oils can contain enormous amounts of “vitamin” A. A 1932 report was literally titled *Halibut Liver Oil as a Source of Vitamin A*.

An older case report, *Hypervitaminosis A and Carotenemia*, described a three-year-old boy who had received about 240,000 USP units of “vitamin” A daily from halibut liver oil since he was about three months old.

What happened?

Enlarged liver.

Enlarged spleen.

Anemia.

Leukopenia.

Abnormal blood lipids.

Skeletal changes.

Finger clubbing.

Coarse, sparse hair.

The report stated:

“Most of the symptoms cleared promptly when excess vitamin A was removed from the diet.”

First, we must stop in-toxing.

Then detoxing can actually get somewhere.

Cod Liver Oil Had the Highest POP Concentrations

Persistent organic pollutants are so nasty that there is an international treaty devoted to them.

The Stockholm Convention explains that POPs resist breakdown, travel widely, accumulate in living organisms, become more concentrated higher in the food chain, and harm humans and wildlife.

The original POP list included DDT, dieldrin, chlordane, heptachlor, PCBs, dioxins, and furans.

These compounds love fat.

Fish live in polluted water.

Bigger fish eat smaller fish.

Predators accumulate in their liver and fat exactly what their prey accumulated.

Then people extract the oil from the fish’s detox organ and take it by the spoonful.

What could possibly go wrong?

A study of persistent organic pollutants in supplements sold in Spain found that the cod liver oil products had the highest concentrations measured.

They exceeded European maximum levels for marine oils intended for human consumption.

Highest concentrations in the study.

Over the regulatory maximum.

Detox-organ juice strikes again.

Cod-Liver-Oil Pollutants Disrupted Testosterone Production

Researchers extracted POP mixtures from different stages of cod liver oil production and applied them to newborn pig Leydig cells.

Leydig cells make testosterone.

What happened?

The cod-liver-oil-derived pollutants disrupted both testosterone and estradiol secretion.

Important steroid-producing genes were downregulated.

The authors noted that seafood and fish oils are major POP sources and that these pollutants may contribute to endocrine disruption and male reproductive dysfunction.

Smaller testes and sterile rats in the old literature.

Disrupted Leydig-cell hormone production in newer research.

Patterns, patterns, everywhere.

Shark Liver Oil: Let’s Concentrate the Top Predator’s Toxins

Sharks are long-lived predators near the top of the marine food chain.

What accumulates as animals eat contaminated animals that ate other contaminated animals?

POPs.

What organ processes and stores many toxins?

The liver.

So naturally, somebody decided to extract shark liver oil and sell it as a supplement.

Researchers examining Japanese shark liver oil products found that two deep-sea shark liver oils contained the highest PBDE and PCB concentrations among the samples studied.

“Deep sea” sounds clean.

The testing said otherwise.

Fish Oil Oxidizes Into Toxic Aldehydes

EPA and DHA are highly unsaturated fatty acids.

That means they oxidize easily.

Oxidation does not merely make the oil smell bad.

It creates toxic aldehydes.

Acrolein.

Malondialdehyde, or MDA.

4-hydroxy-2-hexenal, or 4-HHE.

4-hydroxy-2-nonenal, or 4-HNE.

4-oxo-2-hexenal, or 4-OHE.

These compounds damage proteins, deplete glutathione, bind to DNA, and create mutations.

But DHA is “brain food,” right?

Keep reading.

Cod Liver Oil Produced the Most Acrolein and Malondialdehyde

In an experiment oxidizing different lipids with Fenton’s reagent, the maximum amounts of acrolein and MDA formed from cod liver oil.

The maximum.

Why did Weston Price warn about exposing cod liver oil to air and light?

Because the oil oxidizes.

What does it become as it oxidizes?

More toxic.

Malondialdehyde Mutates DNA

Malondialdehyde reacts with guanine to create DNA adducts.

A study found that the major MDA-DNA adduct caused frameshift mutations and base-pair substitutions in bacterial and mammalian cells.

The researchers said the findings suggested a role for this lesion in mutations associated with human disease.

So what happened when humans consumed cod liver oil?

In *Malondialdehyde excretion by subjects consuming cod liver oil vs a concentrate of n-3 fatty acids*, urinary MDA increased immediately in people taking pharmaceutical-grade cod liver oil without added antioxidants.

The researchers attributed the increase to MDA in the oil.

They concluded:

“Consuming unstabilized fish oils as a source of n-3 fatty acids may entail exposure to potentially toxic products of lipid peroxidation.”

Pharmaceutical grade.

Still delivered potentially toxic lipid-peroxidation products.

The grade does not change the chemistry.

Omega-3 Oxidation Produces a Mutagen Found in Fish Oil

4-Oxo-2-hexenal forms from omega-3 fat peroxidation and produces DNA adducts.

Another paper described 4-OHE as an omega-3-derived mutagen commonly found in fish oil and other dietary fats.

After researchers gave 4-OHE orally to mice, they detected DNA adducts in stomach and intestinal tissue.

Omega-3 oil.

Oxidation.

Mutagenic aldehyde.

DNA adducts.

That is the pathway.

Oxidized DHA Produces a Neurotoxin

The study title says it plainly:

*Trans-4-hydroxy-2-hexenal is a neurotoxic product of docosahexaenoic acid oxidation*.

DHA oxidation produced 4-HHE.

4-HHE and 4-HNE were toxic to cultured cerebral cortical neurons.

Both depleted neuronal glutathione.

DHA is supposedly mandatory for your brain.

One of its oxidation products is neurotoxic to brain cells.

Those statements can both be true only if dose, location, regulation, and oxidation matter.

The supplement story wants you to ignore all four.

A review titled *Oxidation of Marine Omega-3 Supplements and Human Health* noted that concern about oxidized fish oil dates back to the 1950s.

The authors wrote that over-the-counter marine oils are frequently oxidized and that consuming marine oil can increase plasma and urinary MDA through both absorbed peroxides and oxidation inside the body.

Can adding antioxidants completely stop it?

No.

The poison always wins.

“Fermented” Cod Liver Oil Does Not Escape Chemistry

The NIH label entry for Blue Ice Fermented Skate Liver Oil says its naturally occurring vitamins A and D vary.

How much are you getting?

It varies.

How much toxin accumulated in that individual fish?

It varies.

How oxidized is that individual batch?

Good question.

The label calls the product a “raw, unadulterated whole food.”

Oil extracted from dead liver tissue is not a whole food.

Separating oil from an organ is processing.

The label also claims “no additives.”

Adding beeswax and plant cellulose means ingredients were added.

Words still have meanings.

Fermentation normally involves microbial metabolism of suitable substrates, commonly carbohydrates.

What happens when dead animal tissue sits while enzymes and microbes break it down?

It decomposes. It ROTS.

Calling decomposition “fermentation” does not make unstable DHA stop oxidizing.

The Reported Cluster of Premature WAPF Deaths

In 2018, David Gumpert published *Those Ticking Time Bombs Going Off Are WAPF People Dying Too Young*.

He described a disturbing number of premature deaths among people associated with the Weston A. Price Foundation and fermented cod liver oil.

Several cancers.

Multiple glioblastomas.

Gumpert clearly acknowledged that the cases did not prove fermented cod liver oil caused any individual death.

Correct.

Correlation is not automatically causation.

But correlation is where investigation starts.

When multiple people in a health movement die prematurely, several from the same uncommon aggressive brain cancer, while that movement aggressively promotes a rancid oil containing oxidizable DHA, “vitamin” A, vitamin D, and marine pollutants, perhaps asking questions is allowed.

Apparently asking those questions was enough to get people attacked or pushed out.

Nothing says “confident in our science” like punishing anyone who requests better testing.

The Industry-Funded “Fermented” Cod Liver Oil Paper

Two years after Gumpert’s article, a paper appeared reporting that one fermented cod liver oil resisted peroxidation better than three non-fermented oils:

*Determinations of the peroxidative susceptibilities of cod liver oils by a newly-developed 1H NMR-based method*.

Wonderful. Let’s check it for any conflicts of interest.

Who funded it?

The Weston A. Price Foundation financially supported the investigation.

Who did the authors thank?

Dave Wetzel of Green Pasture Products.

Who directed production of product 4, the Green Pasture fermented cod liver oil?

An author identified as JZ.

Where can one get in touch with JZ?

“Green Pasture Products, 416 E. Fremont Street, O’Neill, NE, 68763, USA
J. Zhang”

Who distributed all the samples for analysis?

JZ.

Who was responsible for quality control?

JZ.

The producer-associated author directed production of the favored product, distributed the samples, and handled quality control in a study funded by the organization promoting that product.

And this is supposed to settle the matter?

Seriously?

The conflict does not automatically falsify every measurement. It tells you exactly how much independent reassurance the study provides:

Close to zero.

Glioblastoma: Now Connect the Pieces

Let me state exactly what I am arguing.

No paper proves fermented cod liver oil caused a specific person’s glioblastoma.

The reported WAPF cluster is not a controlled trial.

What the research does show is that the components of cod liver oil—and the oxidation products made from those components—intersect with multiple glioblastoma mechanisms.

DHA oxidation products.

Lipid peroxidation.

Reactive aldehydes.

Iron-driven ferroptosis.

Macrophage suppression.

“Vitamin” A-derived retinoic acid.

Vitamin D metabolites.

Tumor-cell proliferation and invasiveness.

There is a definite pattern.

An Oxidized DHA Product Increased Glioblastoma Invasiveness

A paper titled *4-Hydroxy-7-oxo-5-heptenoic acid lactone is a potent inducer of brain cancer cell invasiveness* examined HOHA lactone.

Where does HOHA lactone come from?

Oxidative fragmentation of a DHA-containing phospholipid.

What did low concentrations do?

They increased migration velocity in cultured glioblastoma stem cells and induced markers associated with a more migratory phenotype.

The authors concluded that HOHA lactone may foster new tumor growth and contribute to treatment failure.

Oxidized DHA product.

More invasive glioblastoma brain-cancer behavior.

There it is.

Fish Oil Increased a Toxic DHA-Derived Aldehyde in Multiple Organs

Researchers identified 4-HHE as a cytotoxic aldehyde generated by DHA oxidation.

Then an animal feeding study found that fish oil increased tissue DHA, 4-HHE, and heme oxygenase-1 expression in multiple organs.

The standard interpretation points to increased heme oxygenase-1 as an antioxidant benefit.

Now ask the obvious question:

Why did the tissues increase a protective antioxidant enzyme?

Because fish oil increased the oxidative product 4-HHE.

Imagine punching somebody in the face and then measuring increased anti-inflammatory activity.

Would you call getting punched an anti-inflammatory therapy?

Apparently fish-oil research can become very magical indeed.

DHA Supplementation Increased Aldehydes in the Brain

In adult mice, DHA supplementation altered phospholipids and increased lipid-peroxidation products in brain, heart, and plasma.

The diet did not contain enough 4-HNE to explain what appeared in the tissues.

The animals made it inside their bodies after eating more DHA.

So the problem is not limited to an already-rancid bottle.

DHA can become toxic aldehydes in vivo.

Inside you.

The More Malignant the Brain Tumor, the More 4-HNE They Found

A human study measured 4-HNE-protein conjugates in astrocytic and ependymal brain tumors.

What happened as malignancy grade increased?

4-HNE-positive tumor cells increased.

Glioblastomas showed significantly higher 4-HNE expression.

The aldehyde appeared in tumor cells and in the lining of tumor blood vessels.

The authors concluded:

“Lipid peroxidation seems to be a common pathologic process in astrocytic and ependymal tumors proportional to the level of malignancy and neovascularization.”

More lipid peroxidation.

More malignancy.

More tumor blood-vessel formation.

Maybe pouring oxidation-prone DHA into this situation is not brilliant.

Iron-Driven Lipid Peroxidation Promoted Glioblastoma Progression

Another study found that neutrophil-triggered ferroptosis promoted tumor necrosis in glioblastoma progression.

Neutrophils triggered iron-dependent lipid-peroxide accumulation in tumor cells.

In human glioblastoma samples, neutrophils and ferroptosis were associated with necrosis and predicted poor survival.

Now connect the pieces.

DHA supplies extremely oxidation-prone fat.

Oxidation creates toxic aldehydes.

Iron drives oxidative chemistry.

“Vitamin” A increases iron absorption and retention.

Cod liver oil delivers DHA and “vitamin” A together.

Do I have a clinical trial proving that exact combination caused glioblastoma in a particular patient?

No.

Do I have a pile of mechanistic evidence pointing in the same ugly direction?

Absolutely.

DHA Killed the Macrophages, Not the Glioma Cells

In glioblastoma tissue, free DHA was approximately five times higher in necrotic areas than in non-necrotic areas.

DHA caused macrophage apoptosis at concentrations the glioma cells survived.

Macrophages pre-exposed to DHA became less able to kill the glioma cells.

Read that again.

The DHA damaged the immune cleanup cells.

The tumor cells survived.

Then the macrophages were worse at attacking the tumor.

But muh brain food!

/sarcasm

Some Glioblastoma Cells Grew in Response to Vitamin D

Cod liver oil also delivers vitamin D.

The paper *Vitamin D3 Metabolism in Human Glioblastoma Multiforme* tested calcitriol and calcidiol in human glioblastoma cultures.

Most lines were insensitive.

But several showed proliferative responses.

Calcidiol promoted proliferation in three of nine cultures.

The authors described this as the first evidence of a mitogenic effect of calcitriol in certain glioblastoma lines.

Does this prove vitamin D causes every glioblastoma?

No.

Does it prove that the active hormone can stimulate some glioblastoma cells?

Yes.

That should matter.

Retinoic Acid Promoted Brain-Tumor Stem Cells

What else does cod liver oil deliver?

Retinol.

What does retinol become?

Retinoic acid.

In cultured brain-tumor stem cells, all-trans retinoic acid increased proliferation.

The authors wrote:

“ATRA alone can promote the proliferation of brain tumor stem cells.”

ATRA is all-trans retinoic acid.

The active form of “vitamin” A.

Promoting brain-tumor stem-cell proliferation.

Another paper found that an ALDH1A3-retinoic acid-PAI-1 signaling pathway promoted glioblastoma cell mobility and invasion.

Retinoic acid again.

Glioblastoma mobility and invasion.

Again.

At some point, “coincidence” stops being an explanation and becomes a refusal to look.

What Should You Do If You Have Been Taking Fish Oil?

First:

STOP IN-TOXING.

You cannot detox a poison efficiently while continuing to swallow it every morning.

You cannot sprinkle antioxidants into an oxidation-prone oil and magically make the problem disappear.

I do not take cod liver oil.

I do not take fish oil.

I do not take krill oil, shark liver oil, skate liver oil, algae oil, flax oil, or bottled omega-3 concentrates.

I would not give them to my children.

Do we use any of these oils to get people better in the Love Your Liver program?

No.

The body can make the fatty acids it needs from dietary precursors when it has adequate nutrition and its metabolic machinery is not being poisoned.

The problem is not that you failed to swallow enough fish fatty-liver juice.

The problem is toxicity.

Flush Niacin Fuels Aldehyde Detoxification

Aldehyde dehydrogenase enzymes convert reactive aldehydes into less-toxic acids.

A study of a lipid-peroxidation aldehyde found that mouse liver ALDH enzymes participated in its detoxification.

Another paper showed that mitochondrial breakdown of 4-HNE is dependent on NAD+ availability.

Less NAD+ availability?

Worse aldehyde detoxification.

What inexpensive nutrient efficiently makes NAD+?

Nicotinic acid.

Flush niacin.

In human lymphocytes, nicotinic acid increased NAD+ and promoted the repair of DNA strand breaks.

What did nicotinamide do under the tested conditions?

It inhibited rejoining of the DNA breaks.

Flush niacin helped.

Niacinamide/nicotinamide inhibited.

Those are not the same thing.

Another study found that nicotinic acid increased NAD+, improved DNA-repair efficiency, and improved genomic stability after X-ray exposure.

This is why I talk about flush niacin constantly.

It is fuel for the detoxification and repair systems required to deal with aldehydes.

Zeolite Clinoptilolite Helps Trap Toxins in the Gut

Properly cleaned and micronized clinoptilolite zeolite stays in the gut, where it can adsorb unwanted compounds and help carry them out.

In odor-adsorption testing, natural clinoptilolite was especially effective at trapping compounds that included acetaldehyde.

In rats after partial liver removal, clinoptilolite lowered malondialdehyde in plasma and liver tissue.

What happened to the animals’ own protective systems?

Glutathione and antioxidant-enzyme activity improved.

Lower toxic aldehyde marker.

Better endogenous antioxidant response.

Exactly what we want.

In lead-exposed mice, clinoptilolite and EDTA reduced lipid peroxidation and helped restore antioxidant-enzyme activity in the brain.

A human study using a defined clinoptilolite product reported significant reductions in nickel and aluminum during long-term supplementation. Arsenic decreased in the shorter trial.

Why does nickel matter here?

Because nickel interferes with detoxification and repair systems.

And for the crucial difference between binders that stay inside the gut and compounds such as modified citrus pectin that can enter the bloodstream, learn more about that here:

This does not mean any random bag of dirty zeolite is safe.

It must be properly cleaned, micronized, and charged with electrolytes to facilitate ion exchange.

The goal is to remove poisons, not buy cheaper ones in a pouch.

The Pattern Is the Point

Let’s put the entire thing together.

Cod liver oil and fish oil research has shown:

· growth suppression;

· diarrhea;

· smaller testes and sterility;

· muscular dystrophy;

· heart damage;

· liver necrosis;

· paralysis;

· allergic reactions;

· increased asthma associations;

· lower adult bone density after childhood use;

· immune-cell suppression;

· persistent organic pollutant contamination;

· disrupted steroid hormone production;

· lipid peroxidation;

· mutagenic DNA adducts;

· and neurotoxic DHA-derived aldehydes.

Then the man whose name is used to sell cod liver oil told us:

It could be injurious.

It could paralyze animals.

It could structurally damage the heart and kidneys.

Air exposure made it more toxic.

And long-term dosing in children produces “toxic effects that often develop.”

What part of this sounds like a safe daily health food?

The bottle gives you unstable PUFAs.

The PUFAs oxidize into aldehydes.

The aldehydes damage proteins and DNA.

The fish oil can carry persistent marine pollutants.

Cod liver oil adds variable doses of “vitamin” A and vitamin D.

The animal experiments show toxicity.

The human studies show concerning long-term associations and measurable biological damage.

Weston Price’s own papers contain explicit warnings.

There it is.

You were not told the whole story.

Now you have it.

Would I take cod liver oil or fish oil?

NO.

Would I give it to my children?

ABSOLUTELY NOT.

If you choose to keep taking it after all of this, you can no longer say nobody warned you.

You can find the flush niacin and zeolite products I recommend here.

Full references doc with links here.