Issue 409: Be Careful with Fish Storage—Watch Out for Histamine!

Have you ever enjoyed a big seafood meal and then experienced facial or oral flushing, swelling, itchy skin, redness, or even hives? If you are not allergic to food, you may have consumed food containing a high level of histamine, leading to food poisoning.

Where does histamine come from?

Histamine may naturally exist in small amounts in seafood, smoked meats, or fermented foods. However, when food is improperly stored, the amino acid histidine can be broken down by microorganisms and converted into large amounts of histamine. Fish such as mackerel, tuna, and bonito are particularly rich in histidine. If left at room temperature for too long, histamine levels can increase rapidly. What makes it more concerning is that histamine is colorless and odorless—it cannot be detected by appearance or smell. Even high-temperature cooking cannot destroy it, and heavy seasoning may further mask the risk.

Symptoms of histamine poisoning usually occur within minutes to 4 hours after consumption. Common symptoms include facial and oral flushing, itchy skin, hives, nausea, vomiting, abdominal pain, diarrhea, difficulty breathing, or numbness. These symptoms resemble food allergies but are not related to an individual’s allergic constitution, so extra caution is needed.

Prevention is better than cure. To avoid histamine formation in fish, choose fresh, high-quality seafood and store it at low temperatures. Remember the following principles:

1. Fish should be rapidly refrigerated or frozen under proper hygienic conditions immediately after being caught.
2. Food handlers should use fresh raw materials, process them under low temperatures, and clean them with potable water to remove internal organs.
3. Consume fish as soon as possible after purchase; if not used immediately, store it in the refrigerator or freezer.
4. Thaw fish at low temperatures (e.g., in the refrigerator) and avoid repeated thawing and refreezing.

Source: Taiwan Food and Drug Administration (TFDA) https://www.fda.gov.tw/tc/PublishOtherEpaperContent.aspx?id=1580&tid=5315&r=557900281