The study, published in Nutrients, suggests that the mineral may provide benefits for cognitive function during the early years of life.
Previous research has shown that zinc may improve cognitive function, but this study is the first to investigate how early zinc exposure influences the characteristics of brain development in newborns.
“Zinc is an essential nutrient in the developing infant brain,” wrote researchers from Brigham and Women’s Hospital, Harvard Medical School, University of Southern California, Children’s Hospital Los Angeles and Columbia University Medical Center.
“Early exposure may play a critical role in neurobiological processes, such as dendritic arborization, synaptogenesis, and axonal growth, which are the structural bases for future neurodevelopmental outcomes.”
The importance of zinc for pregnant women
Zinc has many reported benefits, including reducing inflammation, boosting immunity and improving cognitive function. However, it is estimated that up to 17% of the global population is at risk of inadequate zinc intake.
Pregnant women are particularly vulnerable, as their zinc requirements can double during pregnancy and lactation, with the effects continuing up to two months postpartum.
The researchers therefore recruited 41 adolescent mothers—who have the highest recommended dietary allowance for zinc compared to other age groups—from Columbia University Medical Center and Weill Cornell Medical College.
The participants were assessed three times during their pregnancy (once per trimester). Information about dietary intake was collected during the third trimester using 24-hour dietary recalls.
At three weeks of age, the infants underwent MRI scanning procedures. The Bayley Scale of Infant Development was then used to assess cognitive, language, and motor skill scores at 4, 14 and 24 months.
Zinc has ‘multifaceted effects’ on newborn brain development
Results from the MRI scans showed that zinc intake during pregnancy seemed to influence infant brain development in several ways.
Firstly, greater maternal zinc intake was associated with denser nerve fibres in the newborn brain, which is linked to faster and more efficient communication between brain regions and more effective signal coordination.
Higher zinc intake was also linked to more complex branching of brain cells and synapse formation, which may enhance the brain’s ability to communicate efficiently and process information effectively.
These findings were supported by cognitive development scores at 14 and 24 months, which were higher in infants whose mothers had higher zinc intake during pregnancy.
“Collectively, the data suggest that early zinc exposure has multifaceted effects on newborn brain maturation in diverse regions and tissue types, with potential sustained benefits for cognitive function up to 24 months,” the researchers wrote.
However, while the study confirms a positive association between maternal zinc intake and cognitive development in infants, they noted that the exact pathways through which zinc exerts its influence on cognitive function remain to be fully understood.
“The prospective observational design does not support causal inferences,” the added. “Randomized controlled trials are needed to manipulate maternal diet and zinc intake to discern the causal effects of zinc on newborn brain development.”
The study also noted that biological specimens to assess maternal zinc status were not collected and called for further research with more reliable measures—and with diverse cohorts—to confirm the findings.
Source: Nutrients. doi: 10.3390/nu17020303. “Associations of Maternal Prenatal Zinc Consumption with Infant Brain Tissue Organization and Neurodevelopmental Outcomes.” Authors: P. Berger, et al.
