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Benefit of Docosahexaenoic acid supplements to dark adaptation in
dyslexics
SIR-Makrides and colleagues (June 10, p 1463) provide
strong evidence that docosahexaenoic acid (DHA) is an essential nutrient for the
optimum neural maturation of term infants as assessed by visual evoked potential
acuity. I have data indicating that DHA supplementation in adult dyslexics
improves dark adaptation (scotopic vision) and thus DHA may also be a dietary
essential for this condition. (see dyslexic symptoms)
We measured dark adaptation with a Friedmann
Visual Field Analyser 2, set for the dark adaptation function, in ten adults
with dyslexia and ten controls. Dyslexics showed poorer dark adaptation than
controls, especially in the second part of the curve, which corresponds with rod
dark adaptation (figure, a; repeated measures Anova p<0.05). We subsequently
tested the possibility that dark adaptation might be influenced by DHA. For 1
month five dyslexics and five controls were given 480 mg of DHA daily with no
additional vitamin A or vitamin D. Dark adaptation was then retested (figure, b
and c). In four controls DHA had no effect on dark adaptation, although in one
(a strict vegetarian) adaptation clearly improved. By contrast, in the
dyslexics with poor scotopic vision DHA consistently and significantly improved
dark adaptation (figure, b; paired t-test on final rod threshold, p< 0.04).
It has long been recognised that dyslexics have
both retinal and central processing defects,1,2 but defective dark adaptation has to my knowledge not previously been
reported. DHA is a key fatty acid in both retina and brain and is usually
present in large quantities in these tissues. In these studies I show the
benefit of DHA supplementation for one aspect of retinal function. I have found
that DHA supplements given to dyslexics can also be associated with improvements
in reading ability and behaviour. These reports are anecdotal and subjective
but more formal controlled studies are in preparation.
I thank Ms. Katrina Searle,
Mr. Liam Trow, and Ms. Katy Wood for technical assistance.
The author has a patent on
the use of DHA for dark adaptation.
B Jacqueline Stordy
School of Biological
Sciences, University of Surrey,
Guildford GU2 5XH, UK
- Grosser GS, Spafford
CS. Light sensitivity in peripheral retinal fields of dyslexic and proficient
readers. Perceptual Motor Skills 1990; 71: 467-77.
-
Galaburda
A. Livingstone M. Evidence for a magnocellular defect in developmental
dyslexia. Ann NY Acad Sci 1993; 682: 71-81.
Benefit of Docosahexaenoic acid supplements to dark
adaptation in dyslexics
SIR-Makrides and colleagues (June 10, p 1463) provide
strong evidence that docosahexaenoic acid (DHA) is an essential nutrient for the
optimum neural maturation of term infants as assessed by visual evoked potential
acuity. I have data indicating that DHA supplementation in adult dyslexics
improves dark adaptation (scotopic vision) and thus DHA may also be a dietary
essential for this condition.
We measured dark adaptation with a Friedmann
Visual Field Analyser 2, set for the dark adaptation function, in ten adults
with dyslexia and ten controls. Dyslexics showed poorer dark adaptation than
controls, especially in the second part of the curve, which corresponds with rod
dark adaptation (figure, a; repeated measures Anova p<0.05). We subsequently
tested the possibility that dark adaptation might be influenced by DHA. For 1
month five dyslexics and five controls were given 480 mg of DHA daily with no
additional vitamin A or vitamin D. Dark adaptation was then retested (figure, b
and c). In four controls DHA had no effect on dark adaptation, although in one
(a strict vegetarian) adaptation clearly improved. By contrast, in the
dyslexics with poor scotopic vision DHA consistently and significantly improved
dark adaptation (figure, b; paired t-test on final rod threshold, p< 0.04).
It has long been recognised that dyslexics have
both retinal and central processing defects,1,2 but defective dark adaptation has to my knowledge not previously been
reported. DHA is a key fatty acid in both retina and brain and is usually
present in large quantities in these tissues. In these studies I show the
benefit of DHA supplementation for one aspect of retinal function. I have found
that DHA supplements given to dyslexics can also be associated with improvements
in reading ability and behaviour. These reports are anecdotal and subjective
but more formal controlled studies are in preparation.
I thank Ms. Katrina
Searle, Mr. Liam Trow, and Ms. Katy Wood for technical assistance.
The author has a patent on
the use of DHA for dark adaptation.
B Jacqueline Stordy
-
Grosser GS, Spafford
CS. Light sensitivity in peripheral retinal fields of dyslexic and proficient
readers. Perceptual Motor Skills 1990; 71: 467-77.
-
Galaburda
A. Livingstone M. Evidence for a magnocellular defect in developmental
dyslexia. Ann NY Acad Sci 1993; 682: 71-81.
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