Fish and histamine: 36 foods rated

Anchovies are matured in salt for months, and EU law says how much that costs: products matured in brine are allowed 200 mg/kg of histamine on average and 400 at maximum, against 100 and 200 for other fish. A perfectly legal anchovy fillet carries up to four times what a legal tuna steak may. There is no fresh version of this product on a shelf. The doubling has a name in the regulation — ENZYME MATURATION IN BRINE, which is what curing an anchovy is — and allowing twice as much is the law saying it expects the amine to rise.

• Veciana-Nogues et al., J Food Sci 1989
• Reg. (EC) No 2073/2005 as amended by Reg. (EU) No 1019/2013, which allows 200 mg/kg mean and 400 mg/kg maximum for products matured in brine

Atlantic herring builds histamine faster than almost any other fish once caught, and it is almost never sold truly fresh: rollmops, matjes, kippers and bloaters are all preserved forms, and every one of those processes takes days during which the amines accumulate. The preservation is not the cure - it is part of the cause. The legal criterion of 100 and 200 mg/kg does cover this species, which is rich in HISTIDINE. But it is a SAMPLING PLAN for a batch, not a ceiling on a fillet. A batch passes or fails; a single fish is not what is being judged.

• McCabe-Sellers et al., J Food Compos Anal 2006
• Reg. (EC) No 2073/2005 as amended, for the 100 and 200 mg/kg limits

Herring builds histamine faster than almost any other fish once caught, and it is rarely sold truly fresh — rollmops, matjes, kippers and other pickled, salted or smoked preparations all raise it further. Cooking does not destroy histamine. Treat any herring that is not demonstrably just-caught and kept cold as high.

Sardines are small, oily and rarely gutted before sale, which is the worst combination on this axis: the bacteria that make histamine live in the gut, and in a fish this size there is no distance between the gut and the fillet. Tinned sardines are cooked in the can, which stops further formation but keeps everything already there. The legal criterion of 100 and 200 mg/kg does cover this species, which is rich in HISTIDINE. But it is a SAMPLING PLAN for a batch, not a ceiling on a fillet. A batch passes or fails; a single fish is not what is being judged.

• McCabe-Sellers et al., J Food Compos Anal 2006
• Reg. (EC) No 2073/2005 as amended, for the 100 and 200 mg/kg limits

Smoked salmon is COLD-smoked, at under 30 degrees - the smoke preserves and flavours but never cooks, so the fish spends hours, sometimes a day or two, at a temperature bacteria are perfectly happy with; there is no standard duration and each smokehouse has its own. That is the whole difference from a fresh fillet, and it is why the salmon entry and this one are two different answers. The legal histamine limits of 100 and 200 mg/kg are written for the histidine-rich scombroids, not for this fish - which does not exempt it from the clock.

• Veciana-Nogues et al., J Food Sci 1989
• Reg. (EC) No 2073/2005 as amended by Reg. (EU) No 1019/2013, which allows 200 mg/kg mean and 400 mg/kg maximum for products matured in brine

Tuna is the reference fish for this axis, and the reason is free histidine: the dark muscle of the scombroid family carries far more of it than white fish do, and bacteria turn histidine into histamine as soon as the fish warms. This is the fish behind the term 'scombroid poisoning'. Cooking does not destroy what has already formed, and a tin is fish that was handled long before you saw it. The legal criterion of 100 and 200 mg/kg does cover this species, which is rich in HISTIDINE. But it is a SAMPLING PLAN for a batch, not a ceiling on a fillet. A batch passes or fails; a single fish is not what is being judged.

• McCabe-Sellers et al., J Food Compos Anal 2006
• Reg. (EC) No 2073/2005 as amended, for the 100 and 200 mg/kg limits

Crayfish are liberators like all crustaceans, and their own histamine is governed by the cold chain rather than by the species: storage temperature, how they were handled and which bacteria came with them decide what has formed by the time they reach you. They are usually cooked whole and shelled at the table, which keeps the gut with the meat. The Swiss list rates it 2 of 3 under “crayfish” and marks it H! for rapid histamine formation and L for liberators of mast cell mediators. The letters are a presumed reason, not a measurement. That list is Visciano's, and the species is not on it. What the paper does not cover is liberation — it is about amines formed in the food, and the liberator classification above comes from SIGHI.

• Visciano P, Schirone M, Tofalo R & Suzzi G, Front Microbiol 3:188 (2012), on the factors governing amine formation in raw and processed seafood
• McCabe-Sellers et al., J Food Compos Anal 2006
• SIGHI — Swiss Interest Group Histamine Intolerance, food-compatibility list (2024-08-29), for the entry, its rating and its letters

Lobster is sold live and cooked minutes before eating, which is the shortest cold chain any seafood has - almost no window for bacteria to work. What puts it on this axis is the crustacean liberator effect rather than its own histamine, and leftovers, which gain amines fast once the shell is broken. The Swiss list rates it 2 of 3 under “lobster” and marks it H! for rapid histamine formation and L for liberators of mast cell mediators. The letters are a presumed reason, not a measurement. The legal 100 and 200 mg/kg limits are written for the histidine-rich scombroids, not for this crustacean — which does not exempt it from the clock.

• McCabe-Sellers et al., J Food Compos Anal 2006
• Reg. (EC) No 2073/2005 as amended, for the 100 and 200 mg/kg limits
• SIGHI — Swiss Interest Group Histamine Intolerance, food-compatibility list (2024-08-29), for the entry, its rating and its letters

Mackerel is a scombroid in the strict sense - the family is named for it - and it carries the same high free histidine, the raw material of histamine, as tuna in a much smaller, oilier body that warms faster. It is also landed in bulk and often not gutted immediately, which is when the gut bacteria reach the flesh. Fresh off the boat it is a fine fish; a day on ice in the sun is not. The legal criterion of 100 and 200 mg/kg does cover this species, which is rich in HISTIDINE. But it is a SAMPLING PLAN for a batch, not a ceiling on a fillet. A batch passes or fails; a single fish is not what is being judged.

• McCabe-Sellers et al., J Food Compos Anal 2006
• Reg. (EC) No 2073/2005 as amended, for the 100 and 200 mg/kg limits

Octopus is almost always sold frozen, which is the best case for histamine, and for once that is not a compromise but the preferred state - freezing breaks down the muscle and is how it is tenderised. Frozen from the start means the bacterial window never opens. What raises it is the cooking liquid being kept, and long braises at the back of the fridge. The legal 100 and 200 mg/kg limits are written for the histidine-rich scombroids, not for this cephalopod — which does not exempt it from the clock.

• McCabe-Sellers et al., J Food Compos Anal 2006
• Reg. (EC) No 2073/2005 as amended, for the 100 and 200 mg/kg limits

Salmon carries less free histidine than the scombroid fish, and farmed salmon is gutted and chilled within hours of harvest - which is why it sits below tuna and mackerel despite being just as oily. The oil is not the issue; the histidine and the handling are. The legal histamine limits of 100 and 200 mg/kg are written for the histidine-rich scombroids, not for this fish - which does not exempt it from the clock.

• McCabe-Sellers et al., J Food Compos Anal 2006
• Reg. (EC) No 2073/2005 as amended, for the 100 and 200 mg/kg limits

Shrimp are histamine LIBERATORS: they prompt the body to release its own histamine, so they can cause symptoms while being perfectly fresh and low in histamine themselves. That is the part no cold chain fixes. Their own histamine climbs with temperature on top of it, and fermented shrimp paste is a different food again - sampled products run around 382 mg/kg and some exceed 500. The Swiss list rates it 2 of 3 under “shrimp” and marks it H! for rapid histamine formation and L for liberators of mast cell mediators. The letters are a presumed reason, not a measurement. Visciano names the four things that decide how much histamine forms in raw seafood — storage temperature, handling, which decarboxylase-carrying microbes are present, and how much free amino acid there is for them — and none of them is the species. The liberation above is SIGHI's classification, not this paper's: it is about amines formed in the food, not released by the body.

• Visciano P, Schirone M, Tofalo R & Suzzi G, Front Microbiol 3:188 (2012), on the factors governing amine formation in raw and processed seafood
• McCabe-Sellers et al., J Food Compos Anal 2006
• SIGHI — Swiss Interest Group Histamine Intolerance, food-compatibility list (2024-08-29), for the entry, its rating and its letters

Tilapia is farmed, lean and processed close to harvest, and it carries little free histidine - so its level here is set by the cold chain rather than by the species. It usually arrives frozen, which is the best thing that can happen to a fish on this axis. The legal histamine limits of 100 and 200 mg/kg are written for the histidine-rich scombroids, not for this fish - which does not exempt it from the clock.

• McCabe-Sellers et al., J Food Compos Anal 2006
• Reg. (EC) No 2073/2005 as amended, for the 100 and 200 mg/kg limits

Alaska pollock is caught and frozen at sea within hours, more consistently than almost any other fish - the fleet is built around it. That is why it is the base of fish fingers and surimi, and why it is one of the safer choices here: the cold chain never breaks because it starts on the boat. The legal histamine limits of 100 and 200 mg/kg are written for the histidine-rich scombroids, not for this fish - which does not exempt it from the clock.

• McCabe-Sellers et al., J Food Compos Anal 2006
• Reg. (EC) No 2073/2005 as amended, for the 100 and 200 mg/kg limits

Anglerfish is a lean white fish, low in the free histidine that bacteria turn into histamine - unlike tuna, mackerel and sardine, where the scombroid problem lives. It reaches the counter as a skinned tail rather than a fillet, and firm flesh hides its age better than soft flesh does — which is a texture, not a clock. Freshness is the whole of it: the count climbs with every hour out of the cold, and no label records it.

• Piersanti A. et al., Food Chem 153 (2014) 437-443, four years of official-control histamine results on fish products

Atlantic wolffish is a lean white fish, low in the free histidine that bacteria turn into histamine - unlike tuna, mackerel and sardine, where the scombroid problem lives. Most of it is caught in the North Atlantic and frozen at sea, which is the shortest clock this axis knows. Freshness is the whole of it: the count climbs with every hour out of the cold, and no label records it.

• Piersanti A. et al., Food Chem 153 (2014) 437-443, four years of official-control histamine results on fish products

Carp is the fish with the shortest possible chain: in much of central and eastern Europe it is sold live from a tank and killed at home. A fish killed in your kitchen has had no time to build anything. Freshwater and low in free histidine, it sits at the bottom of this axis when handled that way. Krizek stored carp, rainbow trout and perch at 3 °C and at 15 °C: fillets kept 11 to 16 days and mince 7 to 10 at the low temperature, against 2 to 3 days at the high one — and samples still of good or acceptable quality carried no toxicologically significant histamine or tyramine at all. Putrescine, not histamine, was the amine that tracked spoilage. The legal 100 and 200 mg/kg limits are written for the histidine-rich scombroids, not for this fish — which does not exempt it from the clock.

• McCabe-Sellers et al., J Food Compos Anal 2006
• Krizek M. et al., Acta Vet Brno 80 (2011) 365-374, carp, rainbow trout and perch stored at 3 °C and 15 °C
• Reg. (EC) No 2073/2005 as amended, for the 100 and 200 mg/kg limits

Cod is a lean white fish, low in the free histidine that bacteria turn into histamine - unlike tuna, mackerel and sardine, where the scombroid problem lives. It is sold as loins and fillets, a large share of it frozen at sea — and frozen at sea is the shortest clock there is. Freshness is the whole of it: the count climbs with every hour out of the cold, and no label records it.

• Piersanti A. et al., Food Chem 153 (2014) 437-443, four years of official-control histamine results on fish products

Haddock is a lean white fish, low in the free histidine that bacteria turn into histamine - unlike tuna, mackerel and sardine, where the scombroid problem lives. A good deal of it is sold smoked, and cold smoke is hours at a temperature bacteria are content with — a different answer from a fresh fillet. Freshness is the whole of it: the count climbs with every hour out of the cold, and no label records it.

• Piersanti A. et al., Food Chem 153 (2014) 437-443, four years of official-control histamine results on fish products

Hake has notably soft flesh and spoils faster than cod or haddock - it is the white fish that least forgives a slow journey home. Little free histidine, so a fresh hake is genuinely low; a hake that has sat at the counter is the one white fish where that matters most. The legal histamine limits of 100 and 200 mg/kg are written for the histidine-rich scombroids, not for this fish - which does not exempt it from the clock.

• McCabe-Sellers et al., J Food Compos Anal 2006
• Reg. (EC) No 2073/2005 as amended, for the 100 and 200 mg/kg limits

Halibut is a lean white fish, low in the free histidine that bacteria turn into histamine - unlike tuna, mackerel and sardine, where the scombroid problem lives. It is a large flatfish sold as steaks, and a big fish is cut up days after the catch rather than minutes after it. Freshness is the whole of it: the count climbs with every hour out of the cold, and no label records it.

• Piersanti A. et al., Food Chem 153 (2014) 437-443, four years of official-control histamine results on fish products

Oysters are low in histamine when alive and cold, which is how they are sold - but shellfish are also classic histamine liberators, releasing the body's own stores without carrying much themselves. That is a different mechanism and this level does not cover it. The Swiss list rates it 2 of 3 under “oysters” and marks it H! for rapid histamine formation and L for liberators of mast cell mediators. The letters are a presumed reason, not a measurement.

• SIGHI — Swiss Interest Group Histamine Intolerance, food-compatibility list (2024-08-29), for the entry, its rating and its letters
• Piersanti A. et al., Food Chem 153 (2014) 437-443, four years of official-control histamine results on fish products

Perch is one of the three freshwater species followed in the study behind this level, with carp and rainbow trout, as fillets and as mince, stored at 3 °C and at 15 °C. Samples of good and acceptable quality did not contain toxicologically significant concentrations of histamine or tyramine: the amines are a question of keeping and not of species, since shelf life ran 11 to 16 days at 3 °C and fell to 2 to 3 days at 15 °C. It is also not one of the histidine-rich species the EU histamine criterion covers.

• Křížek M. et al., Acta Vet Brno 80 (2011), biogenic amines in carp, rainbow trout and perch stored at 3 and 15 °C

Plaice is a flatfish, sold as thin fillets that chill through in minutes and cook in about the same - it spends less time at any risky temperature than a thick loin does. Very little free histidine. Fresh, it is one of the lowest fish on this axis. The legal histamine limits of 100 and 200 mg/kg are written for the histidine-rich scombroids, not for this fish - which does not exempt it from the clock.

• McCabe-Sellers et al., J Food Compos Anal 2006
• Reg. (EC) No 2073/2005 as amended, for the 100 and 200 mg/kg limits

Porgies are lean white fish, low in the free histidine that bacteria turn into histamine - unlike tuna, mackerel and sardine, where the scombroid problem lives. They are small fish sold whole, and a small fish is gutted late or not at all before it reaches the ice. Freshness is the whole of it: the count climbs with every hour out of the cold, and no label records it.

• Piersanti A. et al., Food Chem 153 (2014) 437-443, four years of official-control histamine results on fish products

Rainbow trout is farmed, killed to order and often sold within a day - the cold chain is short by design because the fish never travels far. Low free histidine, like all the lean freshwater fish. What changes the answer is smoking, which is a different entry entirely. Krizek stored carp, rainbow trout and perch at 3 °C and at 15 °C: fillets kept 11 to 16 days and mince 7 to 10 at the low temperature, against 2 to 3 days at the high one — and samples still of good or acceptable quality carried no toxicologically significant histamine or tyramine at all. Putrescine, not histamine, was the amine that tracked spoilage. The legal 100 and 200 mg/kg limits are written for the histidine-rich scombroids, not for this fish — which does not exempt it from the clock.

• McCabe-Sellers et al., J Food Compos Anal 2006
• Krizek M. et al., Acta Vet Brno 80 (2011) 365-374, carp, rainbow trout and perch stored at 3 °C and 15 °C
• Reg. (EC) No 2073/2005 as amended, for the 100 and 200 mg/kg limits

Scallops are low in histidine and are usually sold live or frozen at sea, which stops amine formation where it starts. Like other shellfish they can act as liberators, which is a separate question from content. The Swiss list rates it 2 of 3 under “bivalves (mussels, oisters, clams, scallops, ...)” and marks it H! for rapid histamine formation and L for liberators of mast cell mediators. The letters are a presumed reason, not a measurement.

• SIGHI — Swiss Interest Group Histamine Intolerance, food-compatibility list (2024-08-29), for the entry, its rating and its letters
• Piersanti A. et al., Food Chem 153 (2014) 437-443, four years of official-control histamine results on fish products

Sea bass is a lean white fish, low in the free histidine that bacteria turn into histamine - unlike tuna, mackerel and sardine, where the scombroid problem lives. Most sea bass on a European counter is farmed, gutted within hours of harvest and sold whole on ice. Freshness is the whole of it: the count climbs with every hour out of the cold, and no label records it.

• Piersanti A. et al., Food Chem 153 (2014) 437-443, four years of official-control histamine results on fish products

Seabream is a lean white fish, low in the free histidine that bacteria turn into histamine - unlike tuna, mackerel and sardine, where the scombroid problem lives. Most of it is farmed, gutted at harvest and sold whole on ice, which keeps the chain short. Freshness is the whole of it: the count climbs with every hour out of the cold, and no label records it.

• Piersanti A. et al., Food Chem 153 (2014) 437-443, four years of official-control histamine results on fish products

Sole is a lean white fish, low in the free histidine that bacteria turn into histamine - unlike tuna, mackerel and sardine, where the scombroid problem lives. It is a flatfish sold whole, and a whole fish keeps its gut — where the bacteria are — until the kitchen. Freshness is the whole of it: the count climbs with every hour out of the cold, and no label records it.

• Piersanti A. et al., Food Chem 153 (2014) 437-443, four years of official-control histamine results on fish products

Squid is low in free histidine, so it does not produce histamine the way oily fish does. It spoils fast in other ways, which is why it is nearly always sold frozen.

• Piersanti A. et al., Food Chem 153 (2014) 437-443, four years of official-control histamine results on fish products

Surimi is made from lean white fish washed repeatedly until only the protein remains - the washing removes free amino acids along with everything else, including the histidine amines would have come from.

• Piersanti A. et al., Food Chem 153 (2014) 437-443, four years of official-control histamine results on fish products

Swordfish is a lean white fish, low in the free histidine that bacteria turn into histamine - unlike tuna, mackerel and sardine, where the scombroid problem lives. It is a large fish sold as steaks, cut up long after the catch, and its size is why it spends more time in the chain than a small one. Freshness is the whole of it: the count climbs with every hour out of the cold, and no label records it.

• Piersanti A. et al., Food Chem 153 (2014) 437-443, four years of official-control histamine results on fish products

Trout is a lean freshwater fish with little free histidine, and the practical question is which trout: a whole fresh one from a farm counter behaves like the rainbow trout entry, while smoked trout has spent days being cured and belongs with the smoked fish. The word alone does not tell you. Krizek measured the rainbow trout among three freshwater species and found no toxicologically significant histamine in any sample still of good or acceptable quality. The legal 100 and 200 mg/kg limits are written for the histidine-rich scombroids, not for this fish — which does not exempt it from the clock.

• McCabe-Sellers et al., J Food Compos Anal 2006
• Krizek M. et al., Acta Vet Brno 80 (2011) 365-374, carp, rainbow trout and perch stored at 3 °C and 15 °C
• Reg. (EC) No 2073/2005 as amended, for the 100 and 200 mg/kg limits

Turbot is a lean white fish, low in the free histidine that bacteria turn into histamine - unlike tuna, mackerel and sardine, where the scombroid problem lives. It is a thick flatfish, largely farmed now, sold whole or as steaks cut from a fish that has already been on ice. Freshness is the whole of it: the count climbs with every hour out of the cold, and no label records it.

• Piersanti A. et al., Food Chem 153 (2014) 437-443, four years of official-control histamine results on fish products

Whiting is a lean white fish, low in the free histidine that bacteria turn into histamine - unlike tuna, mackerel and sardine, where the scombroid problem lives. It has soft flesh and is among the quickest white fish to go off, so the counter's clock matters here more than anywhere else on this list. Freshness is the whole of it: the count climbs with every hour out of the cold, and no label records it.

• Piersanti A. et al., Food Chem 153 (2014) 437-443, four years of official-control histamine results on fish products