Can Fish Oil Help Childhood ADHD?

Medically Reviewed by Smitha Bhandari, MD on May 27, 2022
5 min read

You may have heard that fish oil can help improve some of the symptoms of attention deficit hyperactivity disorder (ADHD) in kids. It’s true that some research shows some benefits, but other research doesn't. Since these supplements aren’t FDA approved, you need to be careful. Here’s what you should know.

It’s not really the fish oil that helps – it’s the omega-3 polyunsaturated fatty acids that are in fish oil. Your body can’t make omega-3s, so you need to get them from food or supplements. Known as EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), they’re found in fish, seafood, and some algae. They’re essential to maintaining a healthy brain, heart, and immune system.

In addition to EPA and DHA, there’s another type of omega-3 fatty acid, alpha-linolenic acid (ALA). This omega-3 is found in plant-based foods like flaxseed. Although it gets changed into EPA and DHA in the brain, it’s not as efficient as if you actually ate fish or took a fish oil supplement.

Our brains use omega-3s in the hippocampus, the memory center of the brain. If you are low in omega-3 fatty acids, it may be harder to make new memories. Some research has suggested that kids who have low levels of omega-3s have poorer reading and memory and more behavior problems. For example, a 2012 study published in the medical journal PLOS One found that kids given fish oil supplements rich in omega-3 fatty acids for 4 months showed significant improvements in reading skills and behavior. But a follow-up study found that the fish oil supplements didn’t improve reading ability, working memory, or behaviors. It’s important to note that the kids in these studies didn’t have ADHD.

The symptoms of ADHD might be caused by brain cells having trouble sending and receiving neurotransmitters (brain chemicals that communicate information between cells). Omega-3s help neurotransmitters do their job. They also can fight inflammation. But researchers aren’t sure about their exact role in ADHD.

Children and teens with ADHD often have lower levels of omega-3s. Some studies suggest that omega-3 supplements can improve inattention and other symptoms in kids with ADHD.

For example, one study found that 3 months of omega-3 supplementation improved symptoms in a quarter of kids and teens with ADHD; by 6 months, half the kids had shown improvements. Most of the kids who improved had the inattentive type of ADHD.

Supplements don’t help everyone. One reason may be that they only help if a child already has low omega-3 levels. A 2019 study published in the journal Nature studied 92 children with ADHD between 6 and 18 years old. The study measured their blood levels of EPA, then gave them either omega-3 fatty acid EPA or a placebo for 12 weeks. The researchers found that kids who already had low EPA levels were better able to focus and pay attention. But the supplements didn’t help the children who already had normal or high levels of EPA.

The National Institutes of Health says that despite a lot of research, it’s still unclear whether fish oil helps with ADHD. That’s why it shouldn’t be used as a substitute for ADHD medication or behavioral therapy. But it can be taken along with these treatments, as long as your child’s doctor is OK with it. Just keep in mind that any benefit will be pretty modest, compared to prescription ADHD medication. It also takes about 3 months for you to see any effects.

Fish oil is generally considered safe. Side effects can include:

  • An unpleasant taste in your mouth
  • Bad breath
  • Heartburn
  • Nausea
  • Stomach pain
  • Diarrhea
  • Headache
  • Smelly sweat

You may think because fish oil is natural, it’s not a problem to give your child a supplement. But there are side effects, and there’s no set dosage for kids. That’s why it’s always important to talk to your pediatrician first.

That’s one reason why groups like the Academy of Nutrition and Dietetics recommend that parents try to give their kids omega-3 fats via food sources before they try supplements. Kid-friendly options include baked salmon in teriyaki or honey barbecue sauce, or use canned salmon to make salmon sliders or baked nuggets. Choose fish low in mercury, such as:

  • Salmon
  • Sardines
  • Canned light tuna
  • Freshwater trout
  • Herring
  • Oysters
  • Shrimp

The FDA recommends that your child eat about two servings of low-mercury fish high in omega-3s twice a week. It’s worth noting that research suggests that kids with ADHD eat fish and seafood less frequently than kids without ADHD. That’s why you may want to try going the fish route first.

But many kids might not eat enough seafood to get healthy levels of omega-3s. If your child doesn’t eat fish, you might try giving them a supplement.

When you shop for a supplement, make sure:

  • The supplement is mercury-free. Check the label to make sure it says either “mercury-free,” “refined to eliminate mercury,” or “USP.”
  • Use fish body oil, rather than fish liver oil, since liver oil has less omega-3 fats.
  • Avoid cod liver oil. While it is high in omega-3 fatty acids, it may contain too much of vitamins A and D.
  • Don’t use flaxseed oil. It contains high levels of ALA omega-3s, which isn’t the recommended form for kids with ADHD.
  • Consider enteric-coated fish oil supplements. These have a thicker coating, which lowers your child’s chances of having fishy breath. You can also put them in the refrigerator or freezer, too. Liquid supplements may also be easier for your child to take.

Since supplements aren’t regulated by the FDA, there’s no way to know for sure what’s in an over-the-counter fish oil product. One study even found that over 70% of fish oil supplements didn’t contain the stated label amount of EPA or DHA. Only about 20% of those tested contained the amount of EPA they said they did, while only a quarter had enough DHA.

That’s why if you and your child’s doctor decide to have your child take a supplement, it may make sense to consider a prescription supplement. They’re regulated, which means they contain exactly what they say they do. A review of several studies found that even small amounts of omega-3 supplementation can improve kids’ attention, but at least 500 milligrams of EPA are needed to improve hyperactivity symptoms. A prescription supplement generally has anywhere from 700 to 1,600 milligrams of omega-3, depending on your child’s age and weight. It’s not recommended to go over that amount because there have been reports of kids whose behavior got worse after they took 4,000 to 5,000 milligrams over several years.

Remember that fish oil – whether your child gets it from food or a supplement – is just one part of a healthy diet for a kid with ADHD. Research suggests that teens who eat a traditional “Western” diet high in saturated fat, refined sugars, and sodium are more than twice as likely to have ADHD, compared with teens who eat a high-fiber, overall low-fat diet. This doesn’t prove that a Western diet causes ADHD, but it does show the importance of a healthy, balanced diet that includes healthy fats like fish oil.