Are there histamines in sushi? A guide to safe seafood

December 28, 2025 •

3 min read

According to the Food Safety Magazine, histamine poisoning accounts for approximately 40% of all seafood-related foodborne illnesses. While naturally occurring at low levels in all fish, the question of "Are there histamines in sushi?" becomes critical due to the potential for bacterial proliferation in raw seafood. Understanding the conditions that lead to elevated histamine levels is key to enjoying this popular cuisine safely.

Quick Summary

Histamine buildup in certain fish species, like tuna and mackerel, can cause scombroid poisoning if not properly refrigerated after being caught. The heat-resistant toxin causes allergic-like reactions and can form even when fish appears and smells normal. Maintaining a strict cold chain is the most effective way to prevent histamine contamination in seafood.

Key Points

Histamine Formation: Bacteria on fish, primarily from species high in the amino acid histidine (like tuna and mackerel), convert histidine into histamine after the fish dies.
Temperature Control is Crucial: The most critical factor in preventing dangerous histamine buildup is maintaining a strict cold chain from the moment the fish is caught until it is eaten.
Cooking Does Not Destroy Histamine: Once histamine has formed, it is heat-stable and cannot be eliminated by cooking, freezing, or canning, making prevention the only solution.
Symptoms of Scombroid Poisoning: High histamine consumption leads to scombroid poisoning, which causes allergic-like symptoms such as flushing, headaches, nausea, and a peppery taste.
Not a True Allergy: Scombroid poisoning is a form of food poisoning, not a true allergic reaction to the fish itself, although the symptoms can be very similar.
Varies by Individual: The severity of symptoms can vary based on an individual's sensitivity to histamine and the amount of contaminated fish consumed.

Understanding Histamine in Fish

Histamine is a naturally occurring biogenic amine, a compound formed by bacteria breaking down the amino acid histidine, which is naturally present in fish muscle. In healthy, live fish, histamine levels are very low. However, once a fish is caught, the bacteria in its gills and gut can quickly start to convert histidine into histamine, especially when exposed to warm temperatures. This process is the root cause of scombroid poisoning, a foodborne illness that mimics an allergic reaction.

The most important factor controlling histamine formation is temperature. The cold chain must be maintained rigorously from the moment the fish is caught until it is consumed. Histamine is heat-stable, meaning cooking, canning, or smoking contaminated fish will not destroy the toxin once it has formed. This makes prevention through proper handling paramount.

Which fish are most susceptible to histamine buildup?

Certain fish species are naturally higher in histidine, making them more prone to histamine accumulation if handled improperly. The most common species associated with scombroid poisoning belong to the Scombridae family and include:

Tuna (yellowfin, bluefin, and albacore)
Mackerel
Bonito
Mahi-mahi (dolphinfish)
Marlin
Sardines
Anchovies

For sushi lovers, this list includes some of the most popular items. Therefore, strict adherence to food safety protocols is non-negotiable for restaurants and suppliers preparing these fish raw.

Proper Handling and Prevention of Histamine in Sushi

Preventing histamine poisoning in sushi requires diligent temperature control and sanitary practices at every stage of the food supply chain, from the fisherman to the consumer. Simply put, if fish is kept cold enough, fast enough, the bacteria that produce histamine cannot multiply.

Comparison: Safe vs. Unsafe Sushi Practices


Aspect	Safe Handling Practices	Unsafe Handling Practices
Catch & Chill	Fish is rapidly chilled with ice or refrigerated seawater immediately after being caught.	Fish is left on deck for extended periods, especially in warm climates, allowing bacteria to flourish.
Processing & Transport	Seafood processors maintain strict temperature controls, keeping products at or below 4°C (40°F).	The cold chain is broken during transport or at distribution centers, causing temperature abuse.
Restaurant Preparation	Chefs use separate, sanitized cutting boards and utensils for raw fish, and thaw frozen fish properly in a refrigerator.	Poor hygiene, cross-contamination, and thawing fish at room temperature are common issues.
Display & Storage	Prepared sushi is held in refrigerated cases below 5°C (41°F) and discarded at the end of the day.	Sushi is left in unrefrigerated cases or displayed in direct sunlight, or leftovers are resold.
Taste & Quality	Fresh fish has a clean, mild flavor and scent.	Fish may have a peppery, metallic, or sharp taste, which can indicate high histamine levels.

The Risks of Scombroid Poisoning from Sushi

Even with modern standards, foodborne illness outbreaks linked to sushi still occur. While salmonella and other bacteria are also risks, scombroid poisoning is specifically tied to histamine levels. Outbreaks are sometimes linked to issues further up the supply chain, as was the case with a large Salmonella outbreak linked to raw tuna in 2012. The inability to detect high histamine levels by sight or smell adds another layer of risk for the consumer.

For individuals with a sensitivity to histamine, or a deficiency in the enzyme that breaks it down (diamine oxidase), even lower levels can trigger symptoms. This means that while some people may eat contaminated fish with no ill effects, others can experience severe reactions. The varying sensitivity among individuals is why it is often mistaken for a seafood allergy, even though it is a form of food poisoning.

Conclusion: Ensuring Safety and Enjoyment

Ultimately, the question of "are there histamines in sushi?" has a nuanced answer: naturally, yes, but dangerous levels are a product of improper handling, not an inherent property of the food. By understanding the risk factors and being a discerning consumer, you can significantly mitigate the chances of histamine poisoning. Always choose reputable restaurants that prioritize food safety and adhere to strict cold chain management. If you are preparing sushi at home, ensure all fish is from a trusted supplier and kept properly refrigerated. By following these guidelines, you can safely enjoy one of the world's most beloved dishes with peace of mind. For more in-depth information on seafood safety, refer to the FDA's Fish and Fishery Products Hazards and Controls Guidance.

Frequently Asked Questions

Scombroid poisoning is a foodborne illness caused by eating fish that contains high levels of histamine. It is often mistaken for an allergic reaction because the symptoms, such as flushing, headache, and hives, are similar.

Fish from the Scombridae family, including tuna, mackerel, and bonito, are most commonly associated with histamine poisoning because they have naturally higher levels of histidine. Other fish like mahi-mahi and marlin can also cause it.

No, you cannot reliably tell if fish is contaminated. While some heavily spoiled fish may have a peppery taste or bad odor, many contaminated fish will look, smell, and taste completely normal. The toxin is undetectable by the senses.

No, freezing does not destroy histamine. Freezing will stop the bacteria from producing more of the toxin, but any histamine already present in the fish remains. This is why proper cooling immediately after catch is so important.

Reduce your risk by only eating at reputable restaurants with strict food safety standards. Look for places with high turnover, where the fish is unlikely to have been improperly stored. When buying fish to make your own sushi, purchase from a trusted, high-quality fishmonger and keep it chilled at all times.

Symptoms usually appear quickly, from a few minutes to an hour after eating. If you experience mild symptoms, they will likely resolve within 12 hours. For severe symptoms, such as difficulty breathing, seek immediate medical attention.

Not all sushi is at equal risk. The risk is primarily associated with certain finfish species like tuna and mackerel. Sushi made with other ingredients, like vegetables or cooked fish, is not at risk unless there is cross-contamination.