Evidence supports omega-3 supplements for sharper vision in children: Meta-analysis

Supplementing the diet of mothers and infants with omega-3 fatty acids may boost visual acuity and measures of both mental and psychomotor developmental, according to a new meta-analysis of 38 trials.

“We also identified evidence for potentially greater benefits of n–3 PUFA supplementation in both preterm and term infants for visual acuity; and in preterm infants for MDI [mental developmental index],” wrote researchers affiliated with Tufts Friedman School of Nutrition & Science Policy, the University of Michigan Medical School, Harvard Medical School, and Harvard TH Chan School of Public Health.

“These novel findings provide, to our knowledge, the most complete accounting of evidence for potential benefits of n–3 PUFA supplementation on cognitive development in randomized trials.”

On the other hand, no effects were observed for IQ later in the childhood, but that result was based on a more limited data set, they wrote in The Journal of Nutrition.

Implications for dietary guidelines?

Commenting independently on the study Harry Rice, PhD, VP of regulatory & scientific affairs for the Global Organization for EPA and DHA Omega-3s (GOED), told us: “The visual acuity benefit of omega-3 supplementation in pre- and term infants is compelling and should be discussed by the next Dietary Guidelines Advisory Committee (DGAC). Given that the Dietary Guidelines for Americans 2020 will include recommendations from birth to 24 months, the present results are particularly relevant.” 

Study details

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© Getty Images / redstallion (redstallion/Getty Images/iStockphoto)

The researchers pooled data from 38 trials involving mothers, preterm infants, and term infants totaling 5,541 participants.

The results showed that omega-3 supplementation was associated with improvements in MDI in preterm infants, while visual acuity was improved in both preterm and term infants. In addition, a non-significant trend for improvements in visual acuity of infants was also observed for maternal supplementation.

“This systematic review and meta-analysis identified significant benefits of n–3 PUFA supplementation on psychomotor development and visual acuity, with potentially stronger effects in preterm and term infants compared to maternal supplementation,” wrote the researchers.

“We found more equivocal findings for MDI and no significant effects on global IQ later in childhood. Together with observational studies of maternal fish consumption, these findings support benefits of n–3 PUFA on psychomotor and visual acuity development during pregnancy and the first 2 y of life.”

Baseline values

Commenting on potential limitations of their findings, the researchers noted that most of the trials did not measure omega-3 levels at the start of the study period (baseline values).

GOED’s Dr Rice commended the authors’ note about the lack of assessment of baseline omega-3 status. “This is something that GOED and many others have been calling out as a limitation of interpreting the results of many omega-3 studies. It's imperative that all omega-3 studies assess baseline omega-3 status, as well as status after supplementation,” said Dr Rice. “Without this information, the data/results are difficult to interpret with any certainty, because there's always the question of whether or not the supplementation was adequate.” 

Source: The Journal of Nutrition

Volume 148, Issue 3, Pages 409–418, doi: 10.1093/jn/nxx031

“n–3 Fatty Acid Supplementation in Mothers, Preterm Infants, and Term Infants and Childhood Psychomotor and Visual Development: A Systematic Review and Meta-Analysis”

Authors: M. Shulkin, et al.