Herring Oil (Clupea harengus)

Herring oil, derived from Clupea harengus, is rich in long-chain omega-3 fatty acids EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), as well as phospholipids from herring roe. These bioactives modulate immune cell activation and reduce systemic inflammation, with clinical evidence supporting its use in autoimmune skin conditions such as psoriasis.

Origin & History

Herring oil is extracted from Clupea harengus (Atlantic herring), a small oily fish from the North Atlantic, obtained via cold-pressing or solvent extraction from herring flesh, roe, or by-products. The oil contains marine lipids rich in phospholipid-bound omega-3 fatty acids, particularly EPA and DHA in a 3:1 ratio, along with unique long-chain monounsaturated fatty acids like cetoleic acid.

Historical & Cultural Context

No documented evidence of traditional medicinal use in historical healing systems like Ayurveda or TCM was found in available research. Modern interest in herring oil stems entirely from its omega-3 fatty acid content discovered through contemporary nutritional science.

Health Benefits

• Reduces psoriasis severity: Clinical trial (n=64) showed significant PASI score improvements with 2.4g/day herring roe oil over 26 weeks (moderate evidence)
• Modulates immune response: Significantly reduces activated CD38+ T cells and CD107a+CD8+ T cells in psoriasis patients (moderate evidence)
• May support eye health: Preliminary data suggests potential neuroprotective effects in glaucoma (preliminary evidence)
• Lowers cholesterol: Animal studies demonstrate serum cholesterol reduction distinct from other fish oils (preliminary evidence)
• Anti-inflammatory effects: Phospholipid-bound EPA/DHA may dampen Th17/IL-23 pathways, though human cytokine data inconclusive (preliminary evidence)

How It Works

EPA and DHA from herring oil are incorporated into cell membrane phospholipids, competitively inhibiting arachidonic acid metabolism and reducing downstream synthesis of pro-inflammatory eicosanoids such as leukotriene B4 and prostaglandin E2 via COX-2 and 5-LOX pathways. These omega-3 fatty acids also activate PPARγ and GPR120 receptors, suppressing NF-κB signaling and reducing transcription of pro-inflammatory cytokines including TNF-α and IL-17. Herring roe oil specifically downregulates activated CD38+ T cells and cytotoxic CD107a+CD8+ T cells, suggesting a direct modulatory effect on adaptive immune responses relevant to psoriatic inflammation.

Scientific Research

The primary evidence comes from a randomized, double-blind, placebo-controlled trial (PSORAX 35, NCT03359577; PMID: 32378724) testing 2.4g/day herring roe oil in 64 psoriasis patients over 26 weeks, showing significant PASI score improvement. A follow-up immune analysis (PMID: 37744329) revealed significant reductions in activated T cells and NK cell markers in the treatment group (n=10) versus control (n=8).

Clinical Summary

A double-blind randomized controlled trial (n=64) evaluating 2.4g/day herring roe oil over 26 weeks demonstrated statistically significant improvements in PASI (Psoriasis Area and Severity Index) scores compared to placebo, representing moderate-quality evidence. The same trial documented significant reductions in circulating activated CD38+ T cells and CD107a+CD8+ T cells, indicating measurable immunomodulatory effects at that dose. Evidence is currently limited to this primary psoriasis-focused trial, and broader extrapolation to cardiovascular or metabolic outcomes relies on the established omega-3 literature rather than herring-oil-specific trials. Overall, the evidence base is promising but moderate, and larger multicenter trials are needed to confirm and extend these findings.

Nutritional Profile

Herring oil (Clupea harengus) is a marine-derived lipid rich in long-chain omega-3 polyunsaturated fatty acids. Per 100g of oil: ~900 kcal, ~100g total fat. Key bioactive compounds include EPA (eicosapentaenoic acid, ~6-10g/100g oil), DHA (docosahexaenoic acid, ~4-8g/100g oil), and DPA (docosapentaenoic acid, ~1-2g/100g oil). Herring roe oil specifically contains phospholipid-bound omega-3s (~30-50% of total omega-3s as phosphatidylcholine), which enhances bioavailability compared to triglyceride-bound forms found in standard fish oils (absorption estimated 2-3× higher for phospholipid-bound EPA/DHA). Contains naturally occurring vitamin D3 (~200-1000 IU/100g depending on processing), vitamin A (retinol, ~100-500 IU/100g), vitamin E (as alpha-tocopherol, ~1-5mg/100g, often added as antioxidant stabilizer), and trace amounts of astaxanthin (~0.5-2mg/100g in roe-derived oil). Provides minor amounts of selenium (~10-30µg/100g) and iodine. Contains choline (~50-200mg/100g in roe oil due to phosphatidylcholine content). Omega-6 to omega-3 ratio is favorable at approximately 1:10-1:15. Saturated fat content ~15-20g/100g (predominantly palmitic acid C16:0 and myristic acid C14:0). Monounsaturated fat ~20-30g/100g (primarily oleic acid C18:1). Also contains cetoleic acid (C22:1n-11, ~5-10g/100g), a long-chain monounsaturated fatty acid characteristic of herring that may enhance tissue incorporation of EPA/DHA. Virtually no carbohydrates, fiber, or protein in purified oil form. Cholesterol content ~400-600mg/100g. Bioavailability of EPA/DHA from herring oil is generally high when consumed with a fat-containing meal; phospholipid-bound forms (roe oil) show superior intestinal absorption and preferential incorporation into cell membranes and red blood cells compared to ethyl ester or standard triglyceride fish oil supplements.

Preparation & Dosage

Clinical studies used 2.4g/day herring roe oil standardized to contain 378mg phospholipid DHA and 126mg phospholipid EPA (3:1 ratio) for 26 weeks. No clinically validated dosages exist for other forms or conditions. Consult a healthcare provider before starting any new supplement.

Synergy & Pairings

Vitamin D, Turmeric, Vitamin E, Probiotics, Zinc

Safety & Interactions

Herring oil is generally well tolerated at doses up to 2.4g/day, with common mild side effects including fishy aftertaste, burping, and gastrointestinal discomfort. Due to its EPA and DHA content, herring oil may potentiate the anticoagulant effects of warfarin, aspirin, clopidogrel, and other blood-thinning medications, necessitating caution and medical supervision. Individuals with fish or seafood allergies should avoid herring oil entirely, and those with clotting disorders should consult a physician before use. Pregnancy safety has not been specifically evaluated for herring roe oil; while general omega-3 supplementation is considered safe in pregnancy, women who are pregnant or breastfeeding should seek medical guidance before supplementing.