Omega-3 for fat-free kids: Study links DHA to higher fat-free body mass in children

The study, published in The American Journal of Clinical Nutrition, analysed data from more than 150 children enrolled in the long term Kansas University DHA Outcomes Study – finding that a higher maternal intake of docosahexaenoic acid (DHA) from supplementation resulted in children with higher fat-free body mass at five years old.

Led by senior author Professor Susan Carson at the University of Kansas, the team suggest that improving maternal DHA nutrition could have favourable programming effects on the foetus – and that these effects influence body composition into early childhood.

“DHA can be delivered to the foetus by increasing maternal intake during pregnancy and to the breast-fed infant by increasing maternal intake during lactation, which increases DHA in mothers' milk,” said Carlson – who noted that general intakes of omega-3 and DHA are low in many industrialised countries

Major implications?

Study co-author Professor John Colombo noted that the paper makes two important contributions to the field.

"The first contribution is about the effects of DHA," he said. "We've known for a long time that DHA is associated with improvements in visual, cognitive and behavioural development in early life, but these results suggest that DHA may also have a role in promoting a leaner, healthier growth outcome for children.”

"The second contribution is actually more profound,” Colombo added. “If you think about it, our results show the conditions that children experienced during the time that their mothers were pregnant with them are associated with their physical characteristics almost six years later.”

“To me, that's astonishing -- staggering, really,” he said. “Those of us working in the field of developmental science are seeing results that suggest the prenatal environment and prenatal conditions have meaningful, long-term effects on human development.”

“Quite simply, these results add to that mounting evidence. I think we'll learn that much more of how we 'end up' may be strongly influenced or determined by what happens before we are born."

Study details

Carson and her team analysed data from the Kansas University DHA Outcomes Study in which women with low-risk pregnancies in the Kansas City area were enrolled in the study at KU Medical Center's Maternal and Child Nutrition and Development Lab between March 2006 and September 2009.

As part of the trial, half were randomly assigned to a prenatal DHA supplement of 600 milligrams, while half were given a placebo. Five years later, children resulting from those pregnancies were tested using the BodPod, which uses air-displacement to determine body fat and fat-free mass.

The team found that children whose mothers took the DHA supplement during pregnancy had an average of 1.3 pounds more fat-free mass – but the same amount of fat – at age 5 compared with the placebo group.

There was no evidence relating intrauterine DHA exposure to any other body composition measure, the team noted.

"While we don't know the mechanism for the finding, DHA is an omega-3 fatty acid. We do know that the balance of omega-3 and omega-6 fatty acids early in development can influence the balance of muscle and fat cells," Carlson said. "The number of muscle fibres is believed to be set by term birth."

She added that the results of the current study agree with the findings of a previous study undertaken in the United Kingdom.