A fish-oil emulsion added to routine parenteral nutrition in preterm infants appears to offer benefits including cholesterol reduction. However, other findings such as a reduction in arachidonic acid (ARA) may be of concern, according to Italian investigators.
In an online paper in The Journal of Paediatrics, Dr Virgilio Paolo Carnielli of Azienda Ospedaliero-Universitaria Ospedali Riuniti di Ancona, and colleagues note that docosahexaenoic acid (DHA) supplementation of preterm formula lipid blends has become standard practice.
However, currently used fat emulsions for parenteral nutrition generally don't provide this important n-3 long-chain polyunsaturated fatty acid.
Effect of a fish-oil
To examine the effect of a fish-oil emulsion that does, the researchers conducted a pilot study in 47 infants who weighed less than 1250 gm at birth.
They were randomised to receive a lipid emulsion consisting of a physical mixture of 50% medium-chain triacylglycerol along with either 10% fish oil and 40% soybean oil, or soybean oil alone.
Fish oil was well tolerated and at day seven, the fish oil group had significantly lower plasma phospholipids, cholesterol esters, and free cholesterol but similar triglyceride concentrations as in the standard group.
Red blood cell and lipid DHA and eicosapentaenoic acid were significantly higher in the fish oil group than in the standard group.
Nevertheless, arachidonic acid was significantly lower on day seven in the intervention group and was lower, albeit not significantly, on day 14.
The investigators observe that in another study low ARA concentrations in preterm infants receiving a formula containing marine oil were associated with poor growth. "Therefore, the finding of significantly lower ARA in study infants deserves further investigations."
"The impact of 10% fish oil emulsion on inflammation and growth requires further studies with a much larger number of infants," the researchers conclude.(Reuters Health/ March 2011)
Diet and Nutrition