DHA and Reading Ability in Children

Docosahexaenoic acid (DHA) is a long-chain omega-3 fatty acid. It makes up about 15–20% of the fatty acid in brain gray matter and keeps building up through childhood and the teen years. The brain uses DHA in nerve-cell membranes and in the myelin sheath — the fatty insulation around nerve fibers that lets signals travel quickly. That makes adequate DHA important for skills that depend on fast neural processing, like reading, attention, and learning.

How common is low DHA in kids?

Blood DHA levels in children track closely with how much oily fish they eat. The UK National Diet and Nutrition Survey shows that the average child aged 11–18 eats well below the recommended one portion of oily fish per week, and a large share eat none at all in a typical week. Children on plant-based diets are at higher risk: the body can convert plant ALA (from flax, chia, walnuts) into DHA, but conversion is inefficient — usually under 5% in adults, and even less in some children.

Trials on reading and learning

The DOLAB I trial (Richardson et al. 2012, PLoS One, PMID 22970171) randomized 362 UK children aged 7–9 with below-average reading ability to 600 mg/day algal DHA or placebo for 16 weeks. In the pre-specified subgroup of children whose baseline reading was in the lowest 20%, DHA produced a statistically significant improvement on a standardized reading test. The whole-group effect was smaller and not statistically significant. DOLAB II partially replicated this pattern. Older work by Richardson & Montgomery 2005 (the Oxford-Durham study, Pediatrics, PMID 15867020) found EPA/DHA improved reading and behavior in children with developmental coordination disorder. Taken together, the data suggests DHA helps the children who are struggling the most, with smaller average effects in unselected populations.

ADHD and attention

Bloch & Qawasmi’s 2011 meta-analysis (Journal of the American Academy of Child & Adolescent Psychiatry, PMID 21961774) pooled 10 trials and found omega-3 supplementation produced a modest but significant improvement in ADHD symptoms (Cohen’s d ~ 0.31). Effects were larger when EPA dose was higher. This is meaningfully smaller than the effect of stimulant medication, but the safety profile is excellent and the data is consistent.

Practical guidance

Children aged 4–12 with low fish intake can reasonably take 250–500 mg DHA per day; for ADHD or reading concerns, 600 mg/day is the dose used in trials. Algal oil DHA is identical in structure to fish-oil DHA and is the preferred form for vegetarian or vegan kids, or for families who don’t want fish-derived products. Flavored liquid fish oils improve compliance for younger children. If a child reliably eats two servings of oily fish (salmon, mackerel, sardines) per week, a supplement is usually unnecessary. Fish-oil supplements at these doses are well tolerated; the main side effect is fishy burps, which is reduced by refrigerating the bottle and taking it with meals.