Early life cold and heat exposure impacts white matter development in children

Prenatal life and childhood represent periods that are vulnerable to environmental exposures. Both cold and heat may have negative impacts on children’s mental health and cognition, but the underlying neural mechanisms are unknown. Here, by a magnetic resonance imaging assessment of 2,681 children from the Netherlands Generation R birth cohort, we show that heat exposure during infancy and toddlerhood as well as cold exposure during pregnancy and infancy are associated with higher mean diffusivity at preadolescence, indicative of reduced myelination and maturation of white matter microstructure. No associations for fractional anisotropy were observed. Children living in poorer neighbourhoods were more vulnerable to cold and heat exposure. Our findings suggest that cold and heat exposure in periods of rapid brain development may have lasting impacts on children’s white matter microstructure, a risk that must be considered in the context of ongoing climate change.