A new study published in Environmental Health Perspectives looked at the combined exposure to folate and lead during pregnancy and autistic-like behaviors among Canadian children from the Maternal-Infant Research on Environmental Chemicals (MIREC) Pregnancy and Birth Cohort.
“Our study assessed whether the relationship between blood-lead concentrations during pregnancy and childhood autistic behaviours could be mitigated by folate concentrations or folic acid supplementation,” study author Joshua D. Alampi told us. “We hypothesized that the relationship between lead and autistic behaviours would be stronger among study participants with low folic acid supplementation and lower plasma-folate concentrations.”
The research team suspected this to be the case because previous research found that the relationship between pesticides, air pollutants, and phthalates (a component of plastic) and autism/ autistic behaviours was stronger when mothers had lower folic acid supplementation during pregnancy.
“Lead has a tremendous impact on our well-being, as it is toxic at all levels and has numerous health impacts, particularly on brain development,” Alampi told us. “Identifying strategies to mitigate lead’s neurotoxic effects is a step towards improving everyone’s wellbeing. This would be especially beneficial for communities with higher lead exposure.”
The research team used data from a pan-Canadian cohort study, known as the Maternal-Infant Research on Environmental Chemicals (MIREC) study. Participants were recruited during the first trimester of pregnancy. Blood samples were taken during pregnancy to assess lead and folate concentrations. Information was collected on demographics and folic acid supplementation via surveys.
“We documented autistic behaviours with the social responsiveness scale, which is a survey completed by caregivers (parents),” Alampi told us. “Using this data, we built statistical models to assess the lead-autistic behaviour relationship among participants with low, middle, and high folic acid supplementation/ folate concentrations.”
The results from the study suggests that the link between blood-lead levels during pregnancy and childhood autistic behaviours is stronger among participants with lower plasma-folate levels during pregnancy. The researchers measured lead and folate concentrations during the first and third trimester of pregnancy and they found stronger evidence of this mitigation using third trimester samples.
“Our results suggest that having low folic acid supplementation also attenuated the lead-autistic behaviour relationship, but to a lesser extent than plasma-folate levels attenuated it,” Alampi told us. “Our results affirm the current Canadian recommendations regarding folic acid supplementation. If anything, they give another reason to take folic acid supplements, especially if you are at a higher risk of lead exposure.”
Alampi also explained that it would be interesting to repeat this study in a population with higher lead exposure and lower folic acid supplementation.
“Such a population would benefit most from folate mitigating the lead-autistic behaviours relationship,” Alampi told us.