The study, 'Assessing the Effect of Docosahexaenoic Acid on Cognitive Functions in Healthy, Preschool Children: A Randomized, Placebo-Controlled, Double-Blind Study,' found DHA supplementation increased the level of DHA in the bloodstream.
However, in four tests of mental prowess, no statistically significant result was attained between the test group and placebo.
The conclusions were drawn via regression analysis which linked higher levels of DHA in the blood with higher scores on the Peabody Picture Vocabulary Test - a measure of hearing vocabulary that is commonly used to indicate an infant's readiness for school.
Other tests included the Leiter-R Test of Sustained Attention, Day-Night Stroop Test and Conners' Kiddie Continuous Performance Test.
The research, published in the journal Clinical Pediatrics demonstrated that supplementation with 400 mg of DHA per day significantly increased the amount of DHA in the children's blood.
"DHA is a building block of the brain and is important for its development and function throughout life," said Martek medical director, Dr Edward B. Nelson.
DHA is associated with maternal and infant health and Maryland-based Martek has secured a large slice of the infant formula market in European, North American and other markets with its life'sDHA, algae-sourced DHA ingredient.
The ingredient appears in about 95 per cent of infant formula products in the US.
Many studies have confirmed its importance to infant brain development but its value among older children and adults is less well-documented.
Martek said the latest study was, "an extension of the evidence of the beneficial effects of DHA supplementation seen during pregnancy and infancy."
The study was conducted at 11 sites across the US and assessed the effect of DHA supplementation among healthy four-year-old children.
Over four months 175 children were given 400mg of life'sDHA per day or a placebo.
"DHA blood levels were measured using a new finger-stick blood test designed by Martek," the company said.
"Cognitive function was measured with four tests, including the Peabody Picture Vocabulary Test."
Tests were administered by licensed psychologists with at least five years' paediatric experience.
Despite the rise in popularity of the omega-3 category across most demographics, it is estimated US children get less than 30mg of DHA per day through diet.
"The results of this research are promising and highlight the need to investigate further the relationship between DHA and children's cognitive development and performance," said lead investigator Dr. Richard Litov, director of Pedia Research LLC.
DHA, along with EPA (eicosapentaenoic acid), has also been linked with heart and eye health and emerging science demonstrates its ability to benefit skin health and ease problems such as eczema (atopic dermatitis).
Source: Clinical Pediatrics Vol. 47, No. 4, pages 355-362 (2008) " Assessing the Effect of Docosahexaenoic Acid on Cognitive Functions in Healthy, Preschool Children: A Randomized, Placebo-Controlled, Double-Blind Study" Authors: Alan S. Ryan and Edward B. Nelson