Recommendations favouring infant formula with protein levels similar to breast milk, rather than high-protein enriched formula, are not likely to impact brain development or long-term cognitive performance.
A critical window in human brain development occurs between the third trimester of gestation and 2 years of age. Research has suggested that factors – both positive and negative – that affect the brain can have a particularly significant impact on neurological and cognitive development during this period.
One of the factors that is believed to be particularly influential is nutrition. Studies have suggested that proper nutrition during this important early period of brain development may have long-term impact on cognitive functioning and behaviour.
The recognized importance of infant nutrition has led to increased use of enriched infant formula, which contains levels of nutrients, including protein, that exceed the levels typically found in breast milk. However, in recent years, recommendations concerning protein intake for infants have done an about-face, and have tended to favour formulas with lower protein compositions (similar to breast milk) in comparison with previous generations. This trend is largely prompted by initiatives aimed at decreasing the risk of obesity. The change in recommendations has, however, raised questions about whether the anti-obesity measures may come at a cost to cognitive development.
A study recently published in the British Journal of Nutrition suggests that these concerns about the impact on brain development may be unfounded if protein levels in infant formula remain similar to the level contained in breast milk.
The study was a randomized clinical trial in which healthy, full-term infants from five European countries (Germany, Belgium, Italy, Poland and Spain) were recruited and assigned to one of two groups: a high protein (HP) group that was given initial formula with 2.9 g protein/418.4 kJ, followed by a 4.4 protein/100 ml formula as they grew older; and a second low protein (LP) group that received an initial formula with 1.77 g protein/418.4 kJ, followed by a 2.2 g protein/100 ml formula. Formula was given during the first year of life, and the children were then followed until the age of 8 years, during which they participated in a variety of neuropsychological tests. A control group of infants who were exclusively breastfed was also followed and assessed through the period of the study.
The neuropsychological tests administered were designed to assess performance in a wide range of areas including: visual memory, verbal memory, visual attention, sustained attention, visual-perceptual integration, processing speed, visual-motor coordination, verbal comprehension, verbal fluency, impulsivity/inhibition, selective attention, flexibility/shifting, working memory, reasoning, selective and focused attention, visual-spatial skills, decision making and problem solving.
Results of the study showed no statistically significant differences between the performance of children in the HP and LP groups in any of the assessed areas. This remained the case even after adjusting for potential confounding factors such as parental education level and nationality, mother’s age and marital status, maternal smoking, child’s gestational age at birth, delivery type and head circumference at birth and at 8 years of age.
Similarly, results for children in the breastfed control group showed no statistically significant difference in performance in any of the areas assessed by the neuropsychological tests when compared with the formula-fed infants (HP or LP).
Based on these results, authors of the study confirm that recommendations favouring LP infant formulas, which contain levels of protein that are comparable to breast milk, do not appear to have a negative impact on cognitive development when compared to enriched HP formulas.
Written By: Linda Jensen