Millions of children in the United States have been diagnosed with Attention Deficit Hyperactivity Disorder (ADHD) over the years and are on medication for it. A new study suggests that omega-3 fish oil supplements may help some children. While it’s too soon to recommend them as an alternative to medication, the scientists suspect that diet may help with the inattention, hyperactivity and impulsivity that affect kids with ADHD.

These problem behaviors seen in children with ADHD may be the result of differences in how their brains develop or work. The standard treatment for ADHD is stimulant medications like Ritalin.

Children who are deficient in omega-3 are more likely to have troubling ADHD symptoms.

Fish oil has been linked to improved brain function. And previous studies have shown more improvements in ADHD symptoms in children who had low omega-3 levels and were treated with a fish oil supplement compared to children treated with drugs, though findings have been mixed. Other research has also shown that children who are deficient in omega-3 are more likely to have more troubling ADHD symptoms.

To understand the effect omega-3 levels have on ADHD, 92 children between the ages of six and 18 with ADHD were either given high doses of EPA, an omega-3 fatty acid, or a placebo for 12 weeks by researchers from King’s College London and China Medical University in Taiwan.

The results were mixed. Children who had the lowest levels of EPA in their blood displayed improved attention after taking the omega-3 supplement, but children whose blood levels of EPA were normal or high showed no difference. Kids who already had high levels of omega-3 showed a worsening of their impulsivity symptoms when taking the omega-3 supplement.

The study took place in Taiwan where children’s diets are often higher in fish and consequently omega-3s compared to the diets of children in Europe and North America. The average blood levels of EPA in children with ADHD in Western countries are lower than those in this study.

It is important to note that the fish oil supplements worked only in children who had low blood levels of EPA for whom the supplement served to replenish an important nutrient. According to researcher Carmine Pariante of King’s College London, for children who are deficient in the fatty acid, fish oil supplements might be a better option than stimulant medication. “On the other hand, it is possible to have too much of a good thing,” researcher, Jane Chang, said in a statement. “…[P]arents should always consult with their children’s psychiatrists since our study suggests there could be negative effects for some children.”

Omega-3 deficiency in kids is often characterized by dry scaly skin, dry eyes and eczema, but parents should talk to their child’s physician before deciding to give their child fish oil supplements — especially before replacing their child’s ADHD medicine with a supplement.

At this time, fish oil supplements are not approved by the U.S. Food and Drug Administration (FDA) as a treatment for ADHD.

If you have a child with ADHD, including more fatty fish in their diet would be a wise move; however, fish isn’t the only source of EPA. Foods that will add to your child’s intake of beneficial omega-3 fats include walnuts, edamame, kidney beans, chia seeds and flaxseeds, along with mackerel, salmon, oysters, shrimp and trout.

The study was published in Translational Psychiatry.