Fatty acid deficiency signs predict the severity of reading and related difficulties in dyslexic children

ABSTRACT: 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.

NON-TECHNICAL SUMMARY

It has been suggested that dyslexia may involve a relative lack of certain highly unsaturated fatty acids (HUFA). Low blood levels of these fatty acids have already been reported in children with ADHD, and these blood biochemical measures were associated with ratings of well-known physical signs of fatty acid deficiency. (These physical include excessive thirst, frequent urination, rough, dry or 'bumpy' skin, dull or dry hair, and soft or brittle nails.)

In this study, physical fatty acid deficiency signs were therefore assessed (using a simple interview / checklist rating scale) in 97 dyslexic children. Total scores for these physical signs were then examined in relation to reading and related skills. Possible sex differences were also explored.

Children with high ratings of physical fatty acid deficiency signs showed poorer reading and lower general ability than children without. Within boys, these relationships were stronger, and fatty acid deficiency signs were also associated with poorer spelling and working memory. Within females 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.