Published in the Journal of Lipid Research, the findings may help make better decisions when dealing with pre-term birth, low-birth weight, and feeding of infants in intensive care.
While infant formula is now considered nutritionally acceptable for infants under the age of one year, its composition is not a perfect match with breast milk.
The nutritional content of infant formula is regularly refined, and recent improvements include the addition of long-chain n-3 fatty acids, which can improve brain and visual development.
With a view to better understanding the role of n-3 fatty acids in the early development of babies, M. Carole Thivierge and colleagues investigated how these fatty acids affect protein metabolism in neonatal pigs.
Twenty-eight piglets were weaned at two days of age, and raised for a month on either a control formula that did not contain the fatty acid or on a "test" formula that contained 3.5 per cent of the fatty acid from fish oil.
The researchers found that in the piglets that were fed the control formula, fewer proteins were produced in their body over time, and their insulin became less effective at lowering blood sugar levels.
However, piglets that drank the test formula showed increased protein production, and their insulin was as effective at using the proteins in the test formula for their growth as when they were born.
The scientists also found that most of the long-chain n-3 fatty acids were absorbed by muscle cell membranes, and replaced another type of fatty acid known to promote inflammation.
The long-chain n-3 fatty acids were also added to fats called triglycerides, but they did not replace at a similar extent the pro-inflammatory fatty acids there.
Based on the findings, the scientists came to the conclusion that elevated amounts of long-chain n-3 fatty acids in muscle membranes had beneficial effects on the early development of piglets, and might help babies in regulating muscle growth that affect early development and future metabolic health.