5. Herring
The Scandinavian "blue gold" — EPA/DHA bomb, vitamin D, and the Bang–Dyerberg tradition.
Herring in 1 minute
What does it provide? Herring is one of the most useful and cheapest omega-3, vitamin D, and B12 sources in the world. 100 g of herring contains 1.7–2.5 g EPA + DHA, 15–25 µg vitamin D, and 15–20 µg B12 — one serving covers the weekly omega-3 requirement and a large part of the daily vitamin D need.
How much? 100–150 g fresh, baked, or steamed herring 2–3 times per week. Salted / pickled versions (matjes, rollmops, schmaltz herring) once or twice a week — limited due to high salt content.
When to avoid? Histamine sensitivity (MAO inhibitor, atopic dermatitis, mastocytosis). High blood pressure, avoid salted forms. Gout (purine). Allergy.
Herring is one of the most deeply rooted fish in European gastronomy and economy — the economic strength of the 13th–17th-century Hanseatic League partly rested on Baltic Sea herring trade. The Dutch link the invention of the salted-cleaned herring ("haring kaken") technique around 1380 to Willem Beukelszoon, which made long storage and overseas shipping possible. In the 17th-century Dutch Golden Age, the herring fleet ("Buys") of 2,000 ships fished the Dogger Bank — it became part of Dutch national identity.
In Central and Eastern European Jewish cuisine (from Slovakia to Lithuanian shtetls), salted herring was a Sabbath meal staple: schmaltz herring (fatty, salted), matjes (young, lightly salted), forshmak (minced, vinegar-apple-onion). It was one of the pillars of New York immigrant communities ("Lower East Side") in the 19th century. In Scandinavia, the fermented version (Swedish "surströmming") is an extreme curiosity.
In the mid-20th century the North Sea stock dramatically collapsed due to overfishing (1977 complete fishing ban), then slowly recovered through international regulation. Today Atlantic and Pacific herring are positive examples of MSC-certified sustainable fisheries — high omega-3 content, low mercury, and a small carbon footprint.
Scientific Background
Herring's nutrient profile is outstanding. Omega-3 EPA + DHA content is 1.7–2.5 g/100 g — among the highest of commercial fish (salmon ≈ 1.5–2.5 g; sardine ≈ 1.5–2.0 g; tuna ≈ 0.3–0.5 g; cod ≈ 0.2 g).[2008] Meta-analyses (Mozaffarian 2011, Rimm 2018 AHA Science Advisory) show ≈ 36% cardiac-origin mortality reduction with 2 servings of fatty fish per week.[2009][2010]
Vitamin D content is a record: 100 g of herring contains 15–25 µg D3 — surpassing salmon (10–20 µg) and trout (10–15 µg). At northern winter latitudes (including the Carpathian Basin) winter D synthesis is minimal, so dietary D is indispensable. Vitamin D directly modulates the microbiome (Akkermansia muciniphila, Bifidobacterium↑) and gut-barrier integrity (Bashir 2016, Charoenngam 2020).[2016]
Mercury accumulation is low (≈ 0.04 mg/kg) — herring is a small plankton-feeder at the low end of the food chain, with a short life cycle (3–4 years), so it accumulates fewer toxic metals. On the FDA "best choices" list — recommended for pregnant and small-child consumption.[2014] The Atlantic herring stock comes from MSC-certified, sustainable fisheries.[2015]
Coenzyme Q10 (CoQ10) content is also outstanding (≈ 2 mg/100 g), useful for mitochondrial energy production and for statin-treated patients as compensation.
The histamine question: herring is scombroid-type (lots of free histidine in muscle tissue). With improper refrigeration, bacteria decarboxylate histidine to histamine → "scombroid poisoning" (flushing, headache, low blood pressure).[2013] With MAO-inhibitor antidepressants, severe hypertensive crisis is possible. Fresh or freshly frozen herring is safe; old, warm-held herring is to be avoided.
- + Red onion + apple + pickle (forshmak style): classic Central European combination — the polyphenol matrix protects omega-3.
- + Potato (roasted or boiled) + sour cream + chives: classic Scandinavian and Central European combination.
- + Rye bread + reform butter: whole-grain fiber + omega-3 + vitamin D = microbiome super combination.
- + Dill, parsley, chives: essential-oil antioxidant matrix.
- + Lemon: helps iron absorption, plus polyphenol-omega-3 stabilization.
- + Dairy (yogurt, kefir): calcium + live cultures, microbiome synergy.
- + Mediterranean salad (tomato, cucumber, olive, feta): carotenoid-omega-3 cardio synergy.
- MAO-inhibitor antidepressant (phenelzine, tranylcypromine, moclobemide, selegiline) + salted / pickled / smoked herring: severe hypertensive crisis danger! Histamine and tyramine accumulation. Even with fresh herring, caution.
- High blood pressure + matjes / rollmops / schmaltz herring in large portions: salt content is hypertension-aggravating.
- Antihistamine insufficiency (DAO deficiency) + non-fresh herring: scombroid poisoning risk.
- Anticoagulant (warfarin, DOAC) + 5+ servings of fatty fish per week + fish-oil supplement: additive bleeding risk.
- Cold-smoked herring (in pregnancy, immunodeficiency): Listeria risk.
- High Na intake-restriction (heart failure, CKD) + salted herring: contraindicated.
- Deep frying in lots of oil: trans fat + omega-3 oxidation — exactly the opposite of what herring provides.
- Fish allergy (parvalbumin): classic symptoms can reach anaphylaxis.
- Histamine sensitivity, mastocytosis, chronic urticaria, atopic dermatitis flare: herring can be a histamine releaser AND histamine-containing — to be avoided.
- MAO inhibitor antidepressant treatment: strictly avoid salted, pickled, fermented, smoked herring.
- High blood pressure, heart failure, edema: avoid salted forms.
- Chronic kidney disease (CKD 3+): high protein + phosphorus + Na — portion restriction.
- Gout, hyperuricemia: purine content 200–300 mg/100 g (high) — avoid during flare.
- Pregnancy: fresh or thoroughly cooked herring is RECOMMENDED. Cold-smoked, salted, cured forms to be avoided (Listeria, histamine, high Na).
- Immunocompromised patient: avoid fermented surströmming and raw-cured cold-smoked forms.
- Anisakis sensitivity: raw or non-frozen herring carries parasite risk — eliminate by freezing (−20 °C, 7 days) or thorough heat treatment (≥ 63 °C, 15 sec).
- Hyperthyroidism: avoid large portions due to iodine content in untreated Graves' disease.
Daily/weekly serving: 2–3× per week 100–150 g (fresh, baked, steamed); salted / pickled version 1–2× per week.
Preparation pattern — herring grilled over coals (Central European style):
- Fresh herring cleaned, head/tail left on.
- Salt, pepper, dill, lemon zest into the body cavity.
- On grill / over coals 4–5 minutes / side — crispy skin, flaky inside.
- With new potatoes, fresh salad, onion garnish.
Classic patterns:
- Dutch "groene haring" (fresh, mild herring): May-June fresh "matjes" — raw, with onion.
- Matjes herring (mildly salted): salt-cured for 24 hours, with apple, onion, sour cream.
- Rollmops (pickled, stuffed): vinegar + pickle + onion — Central European Jewish kitchen classic.
- Forshmak (Eastern European Jewish): salted herring + apple + onion + vinegar + egg — puréed.
- Scandinavian "pickled herring": mustard, dill, spiced variations.
- Surströmming (Swedish fermented): curiosity — don't start with this.
Storage: fresh herring refrigerated (4 °C) max 24 hours. Frozen (−18 °C) 3–6 months. Salted / pickled herring refrigerated 2–3 weeks unopened.
What not to do: don't eat warm-held (cooled, reheated) herring (histamine!). Don't combine with MAO inhibitor. Don't eat the salted form daily with high blood pressure.
References
[2004] EFSA. Scientific opinion on dietary reference values for fats, EPA, DHA. EFSA Journal 2010;8(3):1461. . 2010. Link
EFSA scientific opinion on dietary reference values for fats, EPA, and DHA.
[2008] USDA FoodData Central. Herring, Atlantic, cooked, dry heat — Nutrient profile. 2024. . 2024.
USDA FoodData Central nutrient profile for Atlantic herring cooked with dry heat (2024).
[2009] Mozaffarian D, Rimm EB. Fish intake, contaminants, and human health. JAMA 2006;296(15):1885–1899. . 2006. Link
CONTEXT: Fish (finfish or shellfish) may have health benefits and also contain contaminants, resulting in confusion over the role of fish consumption in a healthy diet. EVIDENCE ACQUISITION: We searched MEDLINE, governmental reports, and meta-analyses, supplemented by hand reviews of references and direct investigator contacts, to identify reports published through April 2006 evaluating (1) intake of fish or fish oil and cardiovascular risk, (2) effects of methylmercury and fish oil on early neurodevelopment, (3) risks of methylmercury for cardiovascular and neurologic outcomes in adults, and (4) health risks of dioxins and polychlorinated biphenyls in fish. We concentrated on studies evaluating risk in humans, focusing on evidence, when available, from randomized trials and large prospective studies. When possible, meta-analyses were performed to characterize benefits and risks most precisely. EVIDENCE SYNTHESIS: Modest consumption of fish (eg, 1-2 servings/wk), especially species higher in the n-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), reduces risk of coronary death by 36\% (95\% confidence interval, 20\%-50\%; P<.001) and total mortality by 17\% (95\% confidence interval, 0\%-32\%; P = .046) and may favorably affect other clinical outcomes. Intake of 250 mg/d of EPA and DHA appears sufficient for primary prevention.
[2010] Rimm EB et al. Seafood Long-Chain n-3 Polyunsaturated Fatty Acids and Cardiovascular Disease. AHA Science Advisory. Circulation 2018;138:e35–e47. . 2018. Link
AHA Science Advisory by Rimm et al on seafood long-chain n-3 polyunsaturated fatty acids and cardiovascular disease (Circulation).
[2011] GISSI-Prevenzione Investigators. Dietary supplementation with n-3 PUFAs after myocardial infarction. Lancet 1999;354:447–455. . 1999. Link
BACKGROUND: There is conflicting evidence on the benefits of foods rich in vitamin E (alpha-tocopherol), n-3 polyunsaturated fatty acids (PUFA), and their pharmacological substitutes. We investigated the effects of these substances as supplements in patients who had myocardial infarction. METHODS: From October, 1993, to September, 1995, 11,324 patients surviving recent (< or = 3 months) myocardial infarction were randomly assigned supplements of n-3 PUFA (1 g daily, n=2836), vitamin E (300 mg daily, n=2830), both (n=2830), or none (control, n=2828) for 3.5 years. The primary combined efficacy endpoint was death, non-fatal myocardial infarction, and stroke. Intention-to-treat analyses were done according to a factorial design (two-way) and by treatment group (four-way). FINDINGS: Treatment with n-3 PUFA, but not vitamin E, significantly lowered the risk of the primary endpoint (relative-risk decrease 10\% [95\% CI 1-18] by two-way analysis, 15\% [2-26] by four-way analysis).
[2013] Maintz L, Novak N. Histamine and histamine intolerance. Am J Clin Nutr 2007;85(5):1185–1196. . 2007. Link
Review by Maintz and Novak on histamine and histamine intolerance (Am J Clin Nutr).
[2014] FDA. Advice about eating fish — choices for women who are pregnant or breastfeeding. 2022. . 2022.
FDA 2022 advice about eating fish for women who are pregnant or breastfeeding.
[2015] Marine Stewardship Council (MSC). Atlantic herring fisheries — certified sustainable. 2024. . 2024.
Marine Stewardship Council (MSC) certification of Atlantic herring fisheries as sustainable (2024).
[2016] Charoenngam N, Holick MF. Immunologic effects of vitamin D. Nutrients 2020;12(7):2097. . 2020. Link
Review by Charoenngam and Holick on the immunologic effects of vitamin D (Nutrients).