Bell, J.G., Ross, M.A., Cyhlarova, E., Shrier, A., Dick, J.R., Henderson, R.J., Richardson, A.J. (2004) 6th International Congress of the International Study for the Study of Fatty Acids and Lipids (ISSFAL), Brighton UK, 27 June - 1 July 2004.
Increasing evidence implicates functional deficiencies or imbalances of n-3 and n-6 fatty acids in dyslexia, in which specific difficulties with reading and spelling are core features. Our aim was to examine associations between these literacy skills and n-3 and n-6 fatty acid status in dyslexic and non-dyslexic adults.
32 dyslexic adults and 19 matched controls completed standardised tests of reading and spelling and gave venous blood samples for analysis of the polar lipid composition of RBC membranes. Relationships between literacy skills and n-3 and n-6 concentrations were examined using rank order correlations.
Better word reading was associated with higher total n-3 concentrations in both dyslexic and control groups (each p < 0.05, combined sample p < 0.01). In dyslexic subjects only, reading performance also correlated negatively with ratios of LA/ALA and AA/EPA (p < 0.05) and with total n-6 at trend level (p=0.06). Better spelling was related to higher DHA status only in controls, and to lower LA/ALA ratios only in the dyslexic group (p < 0.05).
The finding that n-3 status was directly related to reading performance irrespective of dyslexia supports a dimensional view of this condition, but our other results suggest that n-3/n-6 imbalances might be particularly relevant to dyslexic subjects. This study obviously cannot address causality, but ongoing treatment trials should help to clarify possible implications for dietary management of dyslexia.