Abstract: Two small studies involving 116 children, mainly boys between 10 and 18 years of age, met the inclusion criteria. One study was conducted in a school setting, the other at a specialised clinic. Both studies used three months of a combination of omega-3 and omega-6 supplements as the intervention compared with placebo. Although both studies had generally low risk of bias, we judged the risk of reporting bias as unclear in one study, and as high in the other study. In addition, one of the studies was funded by industry and reported active company involvement in the study. None of the studies reported data on the primary outcomes of reading, writing, spelling and mathematics scores, as assessed by standardised tests. Evidence of low quality indicates that supplementation of PUFAs did not increase the risk of gastrointestinal disturbances (risk ratio 1.43, 95% confidence interval 0.25 to 8.15; two studies, 116 children). Investigators reported no other adverse effects. Both studies reported attention deficit hyperactivity disorder (ADHD)-related behaviour outcomes. We were unable to combine the results in a meta-analysis because one study reported findings as a continuous outcome, and the other as a dichotomous outcome. No other secondary outcomes were reported. We excluded one study because it used a cointervention (carnosine), and five other studies because they did not provide a robust diagnosis of a specific learning disorder. We identified one ongoing study and found three studies awaiting classification. Evidence is insufficient to permit any conclusions about the effect of PUFAs on the learning abilities of children with specific learning disorders. Well-designed RCTs with clearly defined populations of children with specific learning disorders who have been diagnosed by standardised diagnostic criteria are needed.

Plain-language summary: The evidence is current to November 2015. We found two small studies involving 116 children that met our inclusion criteria. Both studies gave children a combination of omega-3 and omega-6 capsules as the intervention for three months. Most of these studies involved boys between 10 and 18 years of age - one was conducted in a school setting, and the other at a specialised clinic. One of the studies was funded by the company that supplied the omega-3 and omega-6 supplements. Another study could not be included in this review because investigators added carnosine (an amino acid that is highly concentrated in the brain) to the PUFAs. Carnosine and PUFAs might have similar effects, so it would not be possible to separate the effects of the two ingredients. Review authors excluded five studies because it was not confirmed that a specific learning disorder was diagnosed in these children. None of the included studies reported effects of PUFAs on reading, writing, spelling or mathematical abilities of children. Evidence of low quality (because studies included few participants and showed evidence of bias) suggests that using PUFAs did not increase the risk of minor disturbances to the digestive system. Included studies reported no other types of adverse effects. Both studies reported on ADHD-related behaviour. However, the format of available data did not allow us to readily combine them or to reach any conclusions. Included studies reported no other secondary outcomes. Evidence is not sufficient to support or refute the use of PUFAs in children with specific learning disorders.