Omega-3 and ADHD: what we know and what we don't

If you have spent any time reading about ADHD, you've probably come across fish oil. It's on supplement shelves, in parenting forums and in plenty of confident headlines. So it's worth slowing down and looking at what the research actually says, because the honest answer is more modest than the marketing.

What omega-3 fats are

Omega-3s are a family of fats the body can't make in useful amounts on its own. The two most studied, EPA and DHA, are found mainly in oily fish. A third, ALA, comes from plants such as flaxseed, chia, walnuts and rapeseed (canola) oil; the body converts only a small amount of ALA into EPA and DHA.

DHA is a major building block of the brain and the retina, which is why omega-3s get so much attention in child development.

What we know

Omega-3s are part of a healthy diet, and most health authorities recommend eating fish, including oily fish, regularly. The NHS suggests at least two portions of fish a week for most people, one of them oily, with some limits on certain types for children because of pollutants (NHS).

Some studies have found that children with ADHD have lower blood levels of omega-3s on average than other children.

What we don't know yet

Whether taking omega-3 supplements actually improves ADHD symptoms is still uncertain. A 2023 Cochrane review, which pooled results from many trials, found little evidence that omega-3 supplements make a meaningful difference to ADHD symptoms in children and teenagers (Cochrane, 2023). Some individual studies have reported small benefits, particularly for children who started with low levels, but the overall picture is not strong enough to recommend fish oil as a treatment.

For autism, the evidence is even thinner. A handful of small trials exist, with mixed results.

In plain terms: omega-3s support general health, and eating oily fish is a good habit. But omega-3s are not a treatment for ADHD or autism, and they shouldn't replace any support your child already gets.

Food first: realistic ways to include omega-3

Salmon is the usual suggestion, but plenty of children won't touch it. Some other options:

• Sardines and mackerel. Cheaper than salmon and very rich in omega-3. Mashed sardines on toast with a little lemon, or mackerel pâté on crackers, can work for children who like strong, salty flavours.
• Tinned salmon. Milder and softer than fresh. Try it in fishcakes or mixed into pasta with a creamy sauce.
• Fish fingers and fish cakes. Many are made with white fish, which is lower in omega-3, but they help build familiarity with fish. Some brands use salmon.
• Omega-3 enriched eggs. These contain a modest amount of DHA and are an easy swap.
• Plant sources. Ground flaxseed stirred into porridge, chia in yoghurt, walnuts (if safe for your child's age), and cooking with rapeseed oil. These supply ALA rather than EPA and DHA, but they still count.

A simple meal

Salmon and potato fishcakes: mash tinned salmon with cooked potato, a little peas or sweetcorn, form into patties, and bake. The texture is soft and uniform, which suits many sensory-sensitive children, and they freeze well.

If your child won't eat fish at all

That's common, and it's okay. Try the plant sources above and omega-3 enriched eggs. Keep offering small amounts of fish alongside safe foods without pressure. If you are worried about intake, talk to a dietitian before choosing a supplement.

Before buying a supplement

If you and your child's doctor decide to try a supplement:

• choose one made for children, with the EPA and DHA content clearly listed
• avoid cod liver oil unless advised, because it also contains vitamin A, which can build up
• check with the doctor if your child takes medication for bleeding problems or has a fish allergy
• give it a fair trial of a few months and be honest about whether you actually notice a difference

Related reading: omega-3 family meals, the gut-brain connection and ADHD and nutrition.