Baby teeth may link autism and heavy metals
NIEHS grantees reported that baby teeth from children with autism contain more lead and lower amounts of the essential nutrients zinc and manganese compared with baby teeth from children without autism. The new findings suggest that autism risk may be influenced by differences in early life exposure to metals and how a child’s body processes them.
The researchers studied twins to help control genetic influences and explore environmental contributors. Participants included 32 pairs of twins and 12 individual twins. The twins had one sibling with autism, both siblings with autism, or neither with autism. The researchers used a method called laser ablation-inductively coupled plasma mass spectrometry to analyze the metal uptake in the teeth’s growth rings, which correspond to different developmental periods, including the prenatal period.
Analyses of the baby teeth revealed that the children with autism exhibited higher lead levels in the prenatal period and in the first five months after birth compared with children without autism. The children with autism also exhibited lower zinc levels during the third trimester and lower manganese levels both prenatally and after birth, with the highest deficiency seen four months after birth. The researchers said that replication in larger studies is necessary to confirm the connection between metal uptake and autism.
Citation: Arora M, Reichenberg A, Willfors C, Austin C, Gennings C, Berggren S, Lichtenstein P, Anckarsater H, Tammimies K, Bolte S. 2017. Fetal and postnatal metal dysregulation in autism. Nat Commun 8:15493.