Can babies have tuna?

The verdict

Yes, but with more care than white fish or salmon needs.

Tuna is not on any national exclusion list for babies. The fish the NHS and the HSE rule out entirely for children are shark, swordfish and marlin; tuna is not among them. But tuna is a large, long-lived predatory fish, and that is precisely the profile that concentrates methylmercury. FSANZ puts the mechanism plainly: the amount of mercury depends on the age of a fish, the environment in which it lives and what it eats, and big fish with long lifespans and predatory fish tend to have higher levels than smaller, younger fish.

So the answer is neither the flat yes that salmon gets nor the flat no that shark gets. Tuna belongs in the rotation, not in the weekly routine.

Why mercury matters more for a baby

Methylmercury crosses into the developing nervous system, and the nervous system is doing most of its building in the first years. FSANZ states that unborn babies, infants and young children are especially vulnerable to excessive mercury intake because they are going through rapid growth and development. The NHS frames the exclusion of shark, swordfish and marlin in the same terms: the mercury in these fish can affect the development of a baby's nervous system.

The countervailing point is real and worth stating. FSANZ is explicit that there is no need for anyone to stop eating fish altogether, that fish is an excellent source of protein, omega-3 fatty acids, iodine and vitamins, and that for most people the benefits of eating fish far outweigh any potential risks related to mercury intake. Cutting fish out of a baby's diet to avoid mercury is a worse trade than serving a varied selection of lower-mercury fish.

Canned, fresh and the light-versus-white distinction

Canned tuna is usually skipjack or yellowfin, which are smaller and shorter-lived than albacore or bluefin. That difference shows up in Canadian advice: HealthLink BC tells parents to choose fish lower in mercury and names canned light tuna in that list, alongside salmon, trout, mackerel, sole, cod, pollock, halibut, herring and sardines. Canned light is the lower-mercury canned product; canned white, which is albacore, is not the one named.

Fresh and frozen tuna steak is generally a larger, older fish than what goes into a light tuna can, so it is the version to serve less often.

One UK nuance catches people out: the NHS notes that fresh and canned tuna do not count as oily fish. Canning removes much of the long-chain omega-3. So tuna does not fill the oily fish slot that salmon, sardines and mackerel do, and it does not count towards the oily fish ceiling either.

How much

This is where the three countries genuinely diverge, and none of them frames it the same way.

The UK sets no specific tuna limit for babies or children. It excludes shark, swordfish and marlin for under-16s, caps oily fish at four portions a week for boys and two for girls, and leaves tuna outside both rules because it is not classed as oily fish. The specific UK tuna limits parents may have seen are pregnancy advice, not infant advice, and they do not transfer.

Australia counts by weight. FSANZ sets one portion for children up to 6 years at 75 grams and builds its whole advisory around portions of that size. It does not name tuna in its highest-restriction category, which is reserved for shark, billfish, orange roughy and catfish.

Canada names species rather than counting portions, steering to canned light tuna as one of the lower-mercury choices.

For a baby, the practical translation of all three is the same: a small serving of canned light tuna occasionally, inside a diet that also has white fish, salmon and non-fish proteins, is comfortably within every framework. Tuna every day is not.

Serving it safely

Canned tuna is soft and flaked, which removes most of the choking concern, but two things still need doing.

Check for bone and skin fragments. Canned tuna is boneless in principle and usually in practice, but the NHS instruction to remove all bones from meat or fish applies here as it does anywhere, and HealthLink BC lists fish bones among the common causes of choking.

Watch the brine. Tuna canned in brine carries meaningful salt, and the salt limit at this age is tight: the NHS sets less than 1g of salt a day for children under 1 year old, and no more than 2g a day for ages 1 to 3. Choose tuna in spring water where you can, drain it well, and rinse it if it is in brine. Tuna in oil is fine from a salt point of view; drain the excess.

Serve it mashed into potato, folded through well-cooked pasta, mixed into a vegetable puree, or spread thinly on a finger of toast. Tuna mayonnaise made with shop-bought mayonnaise is fine in the UK if the mayonnaise is a pasteurised product; homemade mayonnaise raises the raw egg question, which Ireland and Australia answer differently from the UK.

Tuna as an allergen

Fish is one of the common allergens named by the NHS, ASCIA, the AAP and HealthLink BC, and current guidance is to introduce it early rather than late. The NHS says allergen foods can be introduced from around 6 months just like any other foods, and that once introduced and tolerated they should become part of the baby's usual diet to minimise the risk of allergy.

Introduce tuna on its own rather than with other new foods. Fish allergy and shellfish allergy are separate conditions, and a baby who tolerates tuna may still react to prawns.

Where guidance differs

Substantially, in framing rather than in substance. The UK leaves tuna unregulated for children beyond general fish advice and does not count it as oily fish. Australia works in 75-gram portions for under-6s and reserves its strictest limits for shark, billfish, orange roughy and catfish. Canada names canned light tuna as a lower-mercury choice without setting a number.

No authority tells parents to avoid tuna for babies, and no authority recommends it daily. If you want a single rule that satisfies all three, make canned light tuna an occasional fish among several, not the default one.