Question explored with the scientific record
Benifits of extra virgin rat fish liver oil daily as a supplement
The evidence for daily extra-virgin ratfish liver oil is too thin to recommend it. The few studies on fish liver oil in general show both potential benefits and real risks, but none test this specific product in humans.
The retrieved studies do not test ratfish liver oil directly. They test generic fish oil or cod liver oil in animals or lab dishes. One 1981 lab study found that compounds from ratfish liver oil can stimulate human neutrophil movement [1], which is a basic immune-cell effect, not a health benefit or harm. Several animal studies show that fish oil can reduce liver inflammation from toxins [3, 4, 6] and lower triglycerides [9], but other animal studies show that fish oil combined with alcohol worsens liver injury through increased oxidative stress [5, 7]. A 2016 human study of intravenous fish oil in children with liver failure found no deaths or transplants [10], but that is a medical treatment, not a daily supplement.
The biggest concern is contamination. Fish liver oils concentrate fat-soluble pollutants. A 2013 Spanish study found that cod liver and fish oil samples had dioxin and PCB levels up to 30 times higher than whole fish [8]. A 2008 study measured toxaphene (a banned pesticide) in fish liver oil [2]. Ratfish liver oil would face the same problem: the liver stores toxins, and "extra-virgin" is a marketing term, not a safety guarantee.
My call: there is no human evidence that daily ratfish liver oil provides any benefit, and there is documented risk of pollutant exposure from any fish liver oil. Confidence: low for benefit, moderate for contamination risk.
Sources used 10
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Saturated and unsaturated 1-O-alkyl-2-O-acetoyl-sn-glycero-3-phosphocholines derived from ratfish liver oil: effect on human leukocyte migration
This study investigates the effects of saturated and unsaturated 1-O-alkyl-2-O-acetoyl-sn-glycero-3-phosphocholines derived from ratfish liver oil on human leukocyte migration, demonstrating that unsaturated compounds are more potent stimulants of neutrophil chemokinesis and che…
DOI: 10.1016/0009-3084(81)90064-5 -
Determination of toxaphene specific congeners in fish liver oil and feedingstuff using gas chromatography coupled to high resolution mass spectrometry
This study presents a new analytical method for determining nine specific toxaphene congeners in fish liver oil and feedingstuff using gas chromatography coupled with high-resolution mass spectrometry, achieving low detection limits and high recovery rates.
DOI: 10.1016/j.jchromb.2008.02.018 -
Striatal mitochondria response to 3-nitropropionic acid and fish oil treatment
In a rat Huntington's disease–relevant model, fish liver oil partially protects striatal mitochondrial function and reduces cell death after 3-nitropropionic acid exposure by preserving mitochondrial complex III and IV activities, even though complex II inhibition persists.
DOI: 10.1080/1028415x.2016.1237074 -
Dietary fish oil supplementation alters liver gene expressions to protect against LPS-induced liver injury in weanling piglets
n-3 PUFA-rich fish oil modulates liver gene expression and attenuates LPS-induced liver injury in weanling piglets by dampening inflammatory signaling and restoring lipid metabolism.
DOI: 10.1177/1753425918821420 -
Fish Oil, Alcohol, and Liver Pathology: Role of Cytochrome P450 2E1
This study investigates the effects of dietary fish oil versus corn oil on liver injury and cytochrome P450 2E1 induction in rats fed ethanol, revealing that both oils support ethanol-induced liver pathology but with differing severity and biochemical responses.
DOI: 10.3181/00379727-207-43807 -
Fish oil attenuates liver injury caused by LPS in weaned pigs associated with inhibition of TLR4 and nucleotide-binding oligomerization domain protein signaling pathways
This study investigates the hepatoprotective effects of fish oil in alleviating liver injury induced by lipopolysaccharide (LPS) in weaned pigs, highlighting its role in inhibiting TLR4 and NOD signaling pathways.
DOI: 10.1177/1753425912472003 -
Markedly Enhanced Cytochrome P450 2E1 Induction and Lipid Peroxidation Is Associated with Severe Liver Injury in Fish Oil—Ethanol‐Fed Rats
In rats fed fish oil with ethanol, hepatic CYP2E1 induction and lipid peroxidation are markedly enhanced and correlate with more severe liver injury than in corn oil or control groups, suggesting CYP2E1-mediated oxidative stress contributes to fish oil–ethanol–induced liver dama…
DOI: 10.1111/j.1530-0277.1994.tb00119.x -
Polychlorinated dibenzo- p -dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs) in fish, seafood products and fish oil in Spain
This study analyzes 84 samples of fish, seafood products, and fish oil in Spain for polychlorinated dibenzo-p-dioxins, dibenzofurans, and dioxin-like polychlorinated biphenyls, revealing that while most samples are compliant with EU regulations, higher levels were found in cod l…
DOI: 10.1080/19393210.2013.804590 -
Hypotriglyceridemic effect of dietaryn − 3 fatty acids in rats fed low versus high levels of linoleic acid
In a controlled rat study, dietary n-3 fatty acids (fish oil vs. linseed oil) lowered serum and liver triacylglycerol differently depending on background fat type (beef tallow high in saturated fat vs. safflower oil high in linoleic acid), with fish oil producing a pronounced hy…
DOI: 10.1016/0005-2760(89)90333-0 -
Long‐Term Fish Oil Lipid Emulsion Use in Children With Intestinal Failure–Associated Liver Disease
This study demonstrates that children with intestinal failure-associated liver disease can be safely supported on long-term parenteral nutrition and fish oil lipid emulsion therapy without mortality, transplantation, essential fatty acid deficiency, or recurrence of liver diseas…
DOI: 10.1177/0148607116633796