Omega-3 fatty acids supplementation could improve visual acuity development

 
 
 

In a recent global analysis of 38 studies that had been conducted on the effects of omega-3 fatty acids consumption on child cognitive development (which altogether involved 5,541 participants), the outcomes showed that, in comparison with placebo (an innocuous substance), omega-3 fatty acids supplementation improved visual acuity development.

Visual acuity is a measure of the finest detail that can be recognized by the visual system, the clarity or sharpness of vision. The process of vision begins when the eye focuses light onto the retina, where it is absorbed by photoreceptor cells; these cells transform light energy into neurochemical signals. Then, the optic nerve carries these signals from the eye to the brain, which converts the impulses into images. Good visual acuity depends on the small area of the retina that contains photoreceptor cells. Research has shown that photoreceptor cell membranes contain the body’s highest concentrations of DHA (an omega-3 fatty acid), and that diet-induced alterations in retinal fatty acid composition lead to changes in retinal function; omega-3 fatty acid status affects the development of visual acuity, an effect that may be due to changes within the retina, the visual system of the brain, or both.

Visual acuity can be measured with cortical visual evoked potentials (an electrophysiologic test) or by behavioral methods (preferential looking); the basis of the second method is that infants show preferential fixation of a patterned stimulus (for example, black and white gratings) in comparison to a homogeneous field (for example, a grey scale area). Omega-3 fatty acids have been shown to influence both visual evoked potentials and behavioral measures of visual acuity.

Previous studies had already demonstrated that early visual acuity development was accelerated by the supplementation with omega-3 fatty acids. This shouldn’t surprise us, since DHA, the most significant omega-3 fatty acid in the brain, is necessary for the growth and maturation of infant’s brain and retina.

Once again, this shows that the supply of omega-3 fatty acids is particularly important during the second half of pregnancy and during the first two years of life.

Bibliography: 

Shulkin M, Pimpin L, Bellinger D, Kranz S, Fawzi W, Duggan C, et al. N-3 fatty acid supplementation in mothers, preterm infants, and term infants and childhood psychomotor and visual development: a systematic review and meta-analysis. J Nutr. 2018;148(3):409-18.

How Your Eyes Work [Internet]. St. Louis: American Optometric Association [fecha de acceso: 5 de abril de 2018]. 

Neuringer M. Infant vision and retinal function in studies of dietary long-chain polyunsaturated fatty acids: methods, results, and implications. Am J Clin Nutr. 2000;71(1 Suppl):256S-67S.

Weiser MJ, Butt CM, Mohajeri MH. Docosahexaenoic Acid and Cognition throughout the Lifespan. Nutrients. 2016;8(2):99.