Richardson AJ, Calvin CM, Clisby C, Schoenheimer DR, Montgomery P, Hall JA, Hebb G, Westwood E, Talcott JB, Stein JF. (2000) Prostaglandins Leukotrienes and Essential Fatty Acids 63 69-74
It has been proposed that developmental dyslexia may be associated with relative deficiencies in certain highly unsaturated fatty acids (HUFA). In children with attention-deficit/hyperactivity disorder, minor physical signs of fatty acid deficiency have been shown to correlate with blood biochemical measures of HUFA deficiency.
These clinical signs of fatty acid deficiency were therefore examined in 97 dyslexic children in relation to reading and related skills, and possible sex differences were explored.
Children with high fatty acid deficiency ratings showed poorer reading (P<0.02) and lower general ability (P<0.04) than children with few such clinical signs. Within males (n=72) these relationships were stronger, and fatty acid deficiency signs were also associated with poorer spelling and auditory working memory (P<0.05, P<0.005 respectively). Within females (n=25) no associations were significant.
These results support the hypothesis that fatty acid deficiency may contribute to the severity of dyslexic problems, although sex differences merit further investigation.
Copyright 2000 Harcourt Publishers Ltd.
It has been suggested that dyslexia may involve a relative lack of certain special fats - known as long-chain omega-3 and omega-6 fats - which are essential for brain function, but often lacking from modern, western-type diets.
Low blood levels of these fats have already been reported in children with ADHD. and were associated with ratings of well-known physical signs of fatty acid deficiency. These physical signs include excessive thirst, frequent urination, rough, dry or 'bumpy' skin, dull or dry hair, and soft or brittle nails.
In this study, 97 dyslexic children were therefore assessed for physical fatty acid deficiency signs using a simple interview / checklist rating scale. Total scores for these physical signs were then examined in relation to their reading and related skills - for the whole group, and for boys and girls separately.
Children with high scores for physical fatty acid deficiency signs showed poorer reading and lower general ability than children with low scores. In boys, these relationships were stronger, and fatty acid deficiency signs were also associated with poorer spelling and working memory. For the girls only, no associations were significant.
These results support the idea that fatty acid deficiency may contribute to the severity of dyslexic difficulties, but the sex differences found here deserve further investigation.