What is the difference between shark liver oil and fish oil?

Shark liver oil contains high concentrations of squalene (up to 90%) and alkylglycerols, while fish oil primarily provides omega-3 fatty acids EPA and DHA. Shark liver oil focuses on immune support and inflammation reduction, whereas fish oil targets cardiovascular and brain health.

How much squalene is in shark liver oil supplements?

Quality shark liver oil supplements typically contain 60-90% squalene by weight, with some standardized products providing 500-1000mg of squalene per capsule. The concentration varies significantly between products, so checking the squalene content on labels is essential for therapeutic dosing.

Can shark liver oil help with cancer treatment?

Some preliminary studies suggest shark liver oil's alkylglycerols may support immune function during cancer treatment, but current evidence is insufficient to recommend it as a cancer therapy. Patients should consult oncologists before using shark liver oil, as it may interact with certain chemotherapy drugs.

Is shark liver oil sustainable and environmentally safe?

Traditional shark liver oil raises sustainability concerns due to overfishing of deep-sea sharks. Some manufacturers now use sustainably sourced shark liver oil from fishery byproducts, while others offer plant-derived squalene from olive oil or amaranth as eco-friendly alternatives.

What are the side effects of taking shark liver oil daily?

Common side effects include mild digestive upset, fishy aftertaste, and occasional nausea, typically occurring with doses above 1000mg daily. Long-term use may lead to vitamin A toxicity if the product contains high retinol levels, causing symptoms like headache, dizziness, and liver dysfunction.

What does clinical research show about shark liver oil's effect on inflammation?

A clinical trial involving 30 healthy women demonstrated that shark liver oil supplementation significantly reduced C-reactive protein levels from 1.78 to 1.51 mg/L after 6 weeks of use (p=0.014), indicating a measurable anti-inflammatory effect. However, this represents moderate-level evidence, and larger, longer-duration studies are needed to confirm these findings in diverse populations and clinical conditions. The squalene content in shark liver oil is believed to be responsible for modulating inflammatory markers.

Who should avoid shark liver oil supplementation?

Individuals with bleeding disorders, those taking anticoagulant medications like warfarin, and people with shellfish or seafood allergies should consult a healthcare provider before using shark liver oil. Pregnant and nursing women should exercise caution due to limited safety data in these populations, and children should only take shark liver oil under medical supervision. Additionally, people with hypervitaminosis A risk should be aware that shark liver oil is naturally rich in vitamin A and fat-soluble vitamins.

What is the evidence quality for shark liver oil's immune-boosting claims?

Animal studies have shown that shark liver oil can increase lymphocyte proliferation in the thymus and spleen (p<0.05), suggesting immune-enhancing potential. However, human clinical evidence for immune function improvement remains preliminary and limited, with most data coming from animal models rather than controlled trials in people. More rigorous human studies are needed to establish whether the immune benefits observed in animal research translate to meaningful effects in supplement users.

Shark Liver Oil (Squalus acanthias)

Shark liver oil contains high concentrations of squalene and alkylglycerols that support immune function and reduce inflammation. These bioactive compounds work by modulating immune cell activity and enhancing lymphocyte production in the thymus and spleen.

Category: Protein Evidence: 2/10 Tier: Preliminary

Shark Liver Oil (Squalus acanthias) — Hermetica Encyclopedia

Origin & History

Shark liver oil is a lipid-rich extract derived from the livers of deep-sea sharks, particularly Squalus acanthias (spiny dogfish shark), obtained through mechanical extraction or solvent-based methods. The oil contains a complex mixture of bioactive lipids including n-3 polyunsaturated fatty acids, squalene, and alkylglycerols (1-O-alkylglycerols).

Historical & Cultural Context

The research dossier does not provide information about traditional medicine applications or historical usage patterns of shark liver oil.

Health Benefits

• Reduces inflammation markers: Clinical trial in 30 healthy women showed significant reduction in C-reactive protein levels (1.78 to 1.51 mg/L, p=0.014) after 6 weeks of supplementation (moderate evidence)
• Enhances immune function: Animal studies demonstrated increased thymus and spleen lymphocyte proliferation (p<0.05), though human evidence is preliminary
• Improves cell membrane health: Human study showed increased omega-3 fatty acid content and improved erythrocyte membrane fluidity after 6 weeks (moderate evidence)
• May support metabolic health: Crossover trial in 10 overweight males examined plasmalogen enrichment effects, though specific outcomes not detailed (preliminary evidence)
• Potential anti-tumor effects: Rat studies showed reduced Walker 256 tumor weight and reversed cancer cachexia, but human evidence lacking (preliminary evidence)

How It Works

Shark liver oil's primary bioactive compounds, squalene and alkylglycerols, modulate immune cell membrane composition and enhance lymphocyte proliferation. Squalene acts as an antioxidant by scavenging free radicals and stabilizing cell membranes, while alkylglycerols stimulate macrophage activity and increase immunoglobulin production. These compounds also inhibit inflammatory cytokines like TNF-alpha and interleukin-6, reducing systemic inflammation markers.

Scientific Research

Human clinical evidence includes a 6-week RCT in 30 healthy women showing anti-inflammatory effects, a 3-week crossover trial in 10 overweight males examining plasmalogen levels, and a 4-week high-dose immunological study in 13 volunteers. Most evidence comes from small human trials and animal studies, with no large-scale RCTs or meta-analyses available.

Clinical Summary

A clinical trial with 30 healthy women demonstrated shark liver oil's anti-inflammatory effects, reducing C-reactive protein levels from 1.78 to 1.51 mg/L after 6 weeks of supplementation (p=0.014). Animal studies show increased thymus and spleen lymphocyte counts, suggesting enhanced immune function. However, human immune function studies are limited, and most evidence comes from small-scale trials or animal research. The anti-inflammatory effects show moderate evidence strength, while immune enhancement requires more robust human clinical data.

Nutritional Profile

Shark liver oil from Squalus acanthias (spiny dogfish) is a lipid-rich substance, not a true protein source, though it is categorized under protein-associated marine-derived supplements. Key bioactive compounds include: **Alkylglycerols (AKGs):** ~20–30% of total lipid content, primarily 1-O-alkyl-sn-glycerols including chimyl alcohol (16:0), batyl alcohol (18:0), and selachyl alcohol (18:1), typically providing 100–200 mg AKGs per 1 g oil capsule. **Squalene:** ~30–50% of unsaponifiable lipid fraction (approximately 40–80 mg per gram of oil), a triterpene hydrocarbon (C₃₀H₅₀) that serves as a precursor in cholesterol biosynthesis and acts as an antioxidant. **Omega-3 fatty acids:** Contains EPA (eicosapentaenoic acid, ~5–10%) and DHA (docosahexaenoic acid, ~8–15%) of total fatty acid content, contributing anti-inflammatory activity. **Vitamins:** Rich in fat-soluble vitamin A (retinol, ~500–10,000 IU/g depending on extraction and species condition) and vitamin D₃ (cholecalciferol, ~50–200 IU/g). Vitamin E (alpha-tocopherol) is present at lower levels (~0.5–2 mg/g), functioning as a lipid-phase antioxidant. **Minor bioactive lipids:** Contains diacyl glyceryl ethers, pristane (a branched alkane), and trace amounts of free fatty acids. **Minerals:** Negligible mineral content as this is a refined oil extract. **Macronutrient profile per gram of oil:** ~9 kcal, ~1 g total fat, 0 g protein, 0 g carbohydrate. **Bioavailability notes:** Alkylglycerols are well absorbed in the gastrointestinal tract due to their ether-linked lipid structure, which resists enzymatic hydrolysis better than ester-linked lipids; squalene bioavailability is moderate (~60–85% absorption) and is enhanced when taken with dietary fat; fat-soluble vitamins A and D are absorbed via chylomicron-mediated transport and require bile salts for optimal uptake. Potential concern: shark liver oil may contain accumulated environmental contaminants (heavy metals, PCBs) depending on source and purification, which can affect net bioavailability and safety.

Preparation & Dosage

Clinically studied dosages include: 1,500 mg daily for general supplementation (6 weeks), 4 g daily of purified extract (Alkyrol®) for 3 weeks, and high-dose protocols of 3.6 g squalene + 3.6 g alkylglycerols + 750 mg n-3 PUFA daily for 4 weeks. Consult a healthcare provider before starting any new supplement.

Synergy & Pairings

Omega-3 fatty acids, vitamin D3, astaxanthin, CoQ10, vitamin E

Safety & Interactions

Shark liver oil is generally well-tolerated but may cause mild gastrointestinal upset, including nausea and diarrhea in sensitive individuals. It may enhance the effects of anticoagulant medications due to vitamin A content, requiring monitoring in patients taking warfarin or similar drugs. Pregnant and breastfeeding women should avoid shark liver oil due to potential mercury contamination and high vitamin A levels that could cause birth defects. Individuals with fish allergies should use caution, though allergic reactions are rare.