This open pilot study investigated effects of a docosahexaenoic acid (DHA)-rich supplement on learning ability in a group of 20 dyslexic children in Sweden. Children formally diagnosed as dyslexic took eight capsules per day of a long-chain polyunsaturated fatty acid (LC-PUFA) supplement containing high-DHA fish oil and evening primrose oil.

Subjective assessments by the children and their parents were completed at baseline and 6, 12, and 20 weeks after supplementation. Quantitative evaluation by word-chain test was completed before and after 4 months of supplementation to measure word decoding (speed of reading) and letter decoding (motoric-perceptual speed). Subjective parent and child assessments showed increasing numbers of positive responders over time in reading speed, general schoolwork, and overall perceived benefit.

Significant improvements were observed in reading speed and motor-perceptual velocity. Thirteen of 17 children had a significant improvement on the word-chain test (P < .04). Reading speed improved by 60% from 1.76 +/- 0.29 before the study to 2.82 +/- 0.36 after supplementation (P < .01 by Wilcoxon sign test). Motoric-perceptual velocity improved by 23% from a stanine value of 3.76 +/- 0.42 to 4.65 +/- 0.66 after supplementation (P < .05 by Wilcoxon sign test).

Thus LC-PUFA supplementation for 5 months provides positive and clear beneficial effect on variables usually impaired by dyslexia.