Benefit of docosahexaenoic acid supplements to dark adaptation in dyslexics

FAB RESEARCH COMMENT:

This was an 'open' study (i.e. there was no placebo treatment), so expectations or other possible sources of bias cannot be ruled out in explaining the results observed. Nonetheless, as an initial investigation this study served a worthwhile purpose, given the importance of omega-3 fatty acids (and particularly DHA) to many aspects of vision.

A subsequent study, also published in the Lancet, found no evidence of impaired dark adaptation in dyslexia.

• Scotopic sensitivity in dyslexia and requirements for DHA supplementation. Greatrex, J.C., Drasdo, N., Dresser, K. (2000) Lancet. 355(9213) 1429-30.

This initial report by Stordy also helped to stimulate other research, including randomised controlled trials of fatty acid treatment in dyslexia, some of which have shown benefits in other areas. See for example

• A randomized double-blind, placebo-controlled study of the effects of supplementation with highly unsaturated fatty acids on ADHD-related symptoms in children with specific learning difficulties. Richardson, A. J. and Puri, B.K. (2002) Prog Neuropsychopharmacol Biol Psychiatry 26(2) 233-9.