Why fish is worth it
According to the FDA, fish has nutrients that support a child's brain development. These include omega-3 fats (DHA and EPA), iron and choline. Fish also provides protein, vitamin B12, vitamin D and selenium. The FDA says fish can join your baby's diet at around 6 months.
Why mercury matters
Some kinds of fish carry more mercury than others. The NHS says the mercury in these fish can affect how a baby's nervous system develops. Mercury is spread throughout the flesh of the fish. The FDA says cleaning or cooking does not lower it. So the real safeguard is picking a low-mercury kind.
Lists differ by country
In the US, the FDA lists these as choices to avoid: shark, swordfish, marlin, king mackerel, orange roughy, tilefish from the Gulf of Mexico and bigeye tuna. In the UK, the NHS says children under 16 should not eat shark, swordfish or marlin. The FDA's best choices include salmon, sardines, anchovies, freshwater trout and canned light tuna. Check the list from the official authority where you live.
How much and how
The FDA puts a serving for a child aged 1 to 3 at about 1 ounce (about 28 grams) on average. Children this age are advised to have 2 servings of low-mercury fish a week. The FDA does not give a separate serving size for babies under 1. Cook fish to a safe internal temperature and do not serve it raw. The NHS advises removing the bones before giving fish to your baby.
Do not give raw or lightly cooked shellfish such as mussels and oysters, because they raise the risk of food poisoning. For fish caught by your family, check local fish advisories. Ask your doctor if you have questions about your baby's diet.