High doses of the omega-3 fatty acid DHA in baby formula or breast milk may have ‘modest, positive effects’ on the growth of the pre-term infants, including increased length, says a new study from Australia.
The study, published in the British Journal of Nutrition, shows that high dietary intakes of DHA (docosahexaenoic acid) has no adverse effects of the growth of premature babies, according to the researchers, led by Professor Maria Makrides from the School of Paediatrics and Reproductive Health at the University of Adelaide.
In addition, premature infants with a low birth weight and assigned to receive a high dose of DHA had a significantly greater growth rate of the head than infants receiving a standard DHA dose, according to findings published in the British Journal of Nutrition.
Researchers led by, note that this small difference in head growth was associated with a “significant increase in the mental development index”.
“It is possible that even such small, yet statistically significant, increases in the rate of head growth may be associated with neurodevelopmental improvement,” wrote the authors.
An area for further investigation
Commenting on the findings, Harry Rice, PhD, VP regulatory and scientific affairs at the omega-3 trade association Global Organization for EPA and DHA (GOED), told NutraIngredients-USA that what he found interesting about the study was rightfully downplayed by the authors.
“The head circumference of infants born weighing less than 1250 g and randomized to higher DHA was 0.017 cm/week greater than that of infants randomized to standard DHA,” noted Dr Rice. “While statistically significant, it begs the question as to whether or not the difference would be considered clinically significant.
“The answer remains unknown, but consider that in 2009, Makrides et al. reported a significant increase in the mental development index in this same group of infants. This suggests, as pointed out by the authors, that ‘...increases in the rate of head growth may be associated with neurodevelopmental improvement’. At the risk of downplaying the other findings, this association is what I believe deserves further investigation,” he added.
Prof Makrides and her co-workers conducted the Docosahexaenoic acid for the Improvement of Neurodevelopmental Outcome in pre-term infants (DINO) trial in order to evaluate the safety and efficacy of DHA at a dose estimated to match levels built up during time in the womb.
Six hundred and fifty seven infants born before the 33rd week of pregnancy were randomly assigned to one of four groups: Two groups received breast milk and two received formula, with one breast milk and one formula group receiving a standard DHA dose (0.2-0.3 percent of dietary fatty acids), and the other two groups receiving a higher DHA dose (approximately 1 percent of dietary fatty acids).
The test feeding of the babies started between their second and fifth day of life, and was maintained until their expected due date. They were subsequently until 18 months of age. The arachidonic acid (AA) content of the diets was maintained at approximately 0.4 percent of the total fatty acid intake, said the researchers.
Results showed that, at 18 months of age, the infants fed the higher dose of DHA were, on average about 0.7 cm longer than their counterparts fed the standard DHA dose.
“In this trial of DHA supplementation, we have shown that high dietary DHA intakes, capable of suppressing AA tissue incorporation, do not adversely affect the growth of pre-term infants,” stated the researchers.
“The modest, positive effects of the higher-DHA diet on different measures of growth observed in the birth-weight strata are worthy of further investigation, while the consistent lack of effect by infant’s sex indicated that higher-DHA diets have no differential effect on growth by sex,” they concluded.
The study was funded by the Australian National Health and Medical Research Council.The infant formula was provided by Mead Johnson Nutritionals and Nutricia Australasia, while treatment and placebo capsules were provided by Clover Corporation. Some of the researchers, including Prof Makrides, have been advisors to companies such as Nestle, Fonterra, Nutricia, and Wyeth.
Source: British Journal of Nutrition
Published online ahead of print, FirstView Articles, doi:10.1017/S000711451000509X
“Pre- and post-term growth in pre-term infants supplemented with higher-dose DHA: a randomised controlled trial”
Authors: C.T. Collins, M. Makrides, R.A. Gibson, A.J. McPhee, et al.