Tuna

Studies in people

• Open question

  Fish allergy in children⁵

  Kids with fish allergy may tolerate canned tuna, since canning changes the fish protein that triggers reactions.

Study type not stated

• Open question

  Tiny plastic in seafood¹¹

  Tuna caught in some regions held tiny plastic bits, and scientists do not yet know what eating them does to people.

Found in some samples or products

These come from where it was grown, how it was processed or cooked, or what it was made into. They are not about the ingredient itself, so the signal does not count them.

• Contaminated canned fish risk³

  In some countries, mercury in canned tuna was above the level linked to health effects in children and adults.

• Radiation in seafood⁴

  Tuna holds tiny amounts of radioactive substances like potassium-40 and polonium-210, but levels stayed within the safe range for eaters.

• Cancer risk from canned fish⁶

  In Iran, people who eat canned tuna may face a cancer risk from the arsenic in it.

• Allergic reactions to canned fish⁷

  Some canned tuna in Iran contained histamine, but levels stayed below the limit set by the FDA.

• Food poisoning from fish⁸

  Fresh tuna can hold high levels of histamine, which is linked to scombroid poisoning.

• Fish poisoning from histamine⁹

  Tuna can cause food poisoning, and opened tins left out can build up histamine within hours.

• Packaging chemicals in fish¹²

  Canned tuna often held BPA and BPAF, two chemicals also used in some food packaging.

• Regional mercury differences¹³

  Tuna caught near Asia carry more mercury than tuna from other parts of the Pacific.

• How mercury gets absorbed¹⁴

  In tuna, mercury binds to a muscle protein, which may raise how much mercury people take in.

• Buildup through food chain¹⁵

  DDTs were found in yellowfin tuna from the South China Sea, and levels build up through the food chain.

Single cases of misuse or overdose

One person or one incident, such as an accidental overdose or a mistake in a kitchen or factory. They are real, but a single case does not show what happens at normal amounts, so the signal does not count them.

• Reaction to fish¹⁰

  Some tuberculosis patients taking isoniazid got a reaction after eating tuna, while family members not on it that day were fine.

The signal at the top counts the findings in people and in animal and lab studies. A concern in studies of people outranks animal and lab studies, and “No concerns” needs at least one finding in people. When most findings in people point one way, the page leans that way (“Mostly”), and every finding is still shown. Findings whose study type is not stated are shown but not counted. This page is a reference, not medical advice. It describes what regulators and published research say. Talk to a doctor or dietitian about your own diet.