Rationale of Polyunsaturated Fatty Acids Supplementation in the Frame of the Magnocellular Theory of Dyslexia

Abstract

In the last decades evidence has been collected that the depletion of the visual magnocellular population (a fast-conduction cellular system made of large ganglion neurons) plays a pathogenetical role in developmental dyslexia. Smaller size of the magnocells and reduction of their overall number in a proportion of disabled readers, in fact, are believed to hamper the visual processing of the written text. Polyunsaturated fatty acids (PUFAs) are important structural parts of the cellular membrane and of the cytoskeleton, and are pivotal for the correct development and functioning of neurons. Magnocells are thought to be particularly vulnerable to PUFAs deficiency, due to the large extent of their plasma membrane: so, reduced availability of polyunsaturated fatty acids is argued to selectively affect the magnocellular population. Indeed, PUFAs deficiency has been reported in a consistent proportion of disabled readers. This finding has led to hypothesize this deficiency may play a main role in the reading problems of patients by hindering the normal development of their magnocellular pathway. Based on these assumption there is some evidence that dietary supplementation with a predefined combination of omega-3 and omega-6 fatty acids has a beneficial effect on the reading performance and behavior of dyslexics. Here the rationale for this line of intervention is reported. The conclusion is that supplementation of dyslexic children with PUFAs is worth to be considered, despite its effectiveness in improving their academic skills needs further clarification.