Understanding the Factors Behind Histamine Formation in Tuna



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I’m a Naturopath, MTHFR & Methylation Specialist. I’m dedicated to helping you achieve your health goals so you can live a vibrant & fulfilling life

Understanding the Factors Behind Histamine Formation in Tuna


Tuna, a popular seafood choice, can be a trigger for individuals with histamine intolerance. Understanding the factors that contribute to histamine formation in tuna is essential for managing histamine-related symptoms effectively. In this article, we will delve deeper into the microbial breakdown of histidine, the impact of processing, and other factors that can cause histamine to form in tuna.

Microbial Breakdown of Histidine

Histamine formation in tuna occurs through the breakdown of histidine, an amino acid, into histamine by specific bacteria. The meat of tuna contains a significant amount of histidine, providing a substrate for histamine production. Bacteria present in the gut of fish initiate the breakdown of tissue proteins into histidine immediately after the fish’s death and continue until the fish has been gutted. As these bacteria multiply rapidly, histamine levels in the fish’s tissues can double every twenty minutes.

Processing and Histamine Levels

The processing of fish plays a crucial role in histamine levels. The time from catch to gutting and the time from gutting to consumption can greatly impact histamine formation. The longer the time between these stages, the higher the potential for histamine to accumulate. Factors such as temperature abuse during processing, improper handling, and extended storage can contribute to increased histamine levels in tuna.

Thawing and Tinned Tuna​

Thawing tuna from a frozen state provides an opportunity for the degradation of histidine and the subsequent formation of histamine. During thawing, bacteria present in the fish can continue to produce histamine if not properly controlled. Additionally, once tinned tuna is opened, histamine formation can occur, especially if it is not stored correctly. Therefore, it is crucial to handle and store tuna properly to minimize histamine accumulation.

Role of Gut Bacteria

The level of bacteria in the bowel can also influence the conversion of histidine into histamine. An imbalance of gut bacteria or an overgrowth of histamine-producing bacteria can contribute to higher histamine levels in the body. Maintaining a healthy gut microbiome through a balanced diet and proper gut health practices may help manage histamine intolerance more effectively.


Histamine formation in tuna is a result of the microbial breakdown of histidine, high levels of histidine in tuna meat, and various processing factors. Understanding these factors can help individuals make informed choices and take necessary precautions to minimize histamine levels in tuna. Proper handling, timely gutting, appropriate thawing methods, and adequate storage are key to reducing histamine-related symptoms.

It is important to note that individual tolerance to histamine can vary. If you have histamine intolerance or concerns about consuming tuna, consulting with a healthcare professional or registered dietitian is recommended for personalized advice and guidance.

By being aware of the factors that contribute to histamine formation in tuna and practicing proper food handling and storage, you can continue to enjoy tuna as part of a balanced diet while effectively managing histamine intolerance.


This article is meant for informational purposes only and should not be considered a substitute for professional medical advice.

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