Summary: A recent study suggests that folic acid supplementation during pregnancy may help mitigate the link between maternal blood lead levels and autistic-like behaviors in children. Researchers analyzed data from pregnant women and their toddlers, revealing that stronger associations between lead exposure and autism traits were present in cases of low folic acid intake.
Adequate folic acid intake of 0.4 mg daily appears to lessen these neurotoxic effects, while no additional benefits were observed with higher dosages. This aligns with recommendations for folic acid intake to support neurodevelopment and reduce potential environmental risks.
Key Facts:
- Folic acid may reduce autism risks linked to lead exposure during pregnancy.
- Stronger lead-autism associations were noted in cases of low folic acid intake.
- High levels of folic acid (>1.0 mg/day) did not confer extra protective effects.
A new study by Simon Fraser University researchers has indicated that folate may weaken the link between blood lead levels in pregnant women and autistic-like behaviors in their children.
Researchers from SFU’s Faculty of Health Sciences, led by PhD candidate Joshua Alampi, published their findings in the journal Environmental Health Perspectives.
“Folic acid supplementation during pregnancy has numerous benefits to child health, particularly for brain development,” states Alampi. “Our study suggests that adequate folic acid supplementation can reduce the neurotoxic effects of lead.”
This SFU-led study is the first to identify that sufficient folic acid supplementation may lower the risk associated with gestational lead exposure and autism. It found that the connections between blood lead levels and autistic-like behaviors in toddlers were significantly stronger among pregnant women consuming less than 0.4 milligrams per day of folic acid.
Folate, as well as folic acid—a synthetic form found in fortified food—has been recognized as a crucial nutrient during pregnancy. Folate consumption is vital for brain development and plays a role in preventing neural tube defects.
Prior studies indicate that associations between autism and exposure to pesticides, air pollutants, and phthalates are more pronounced when folic acid intake is insufficient.
The research team analyzed data collected from 2008 to 2011 involving 2,000 Canadian women enrolled in the MIREC study (Mother-Infant Research on Environmental Chemicals). Blood lead levels were measured during the first and third trimesters, while participant surveys quantified their folic acid supplementation.
Children in this cohort were evaluated at ages three to four using the Social Responsiveness Scale (SRS), which documents autistic-like behaviors in toddlers.
“The study’s findings correspond with Health Canada’s recommendation that all individuals who are pregnant, lactating, or could become pregnant should take a daily multivitamin containing 0.4 milligrams of folic acid,” Alampi added.
About This Neurodevelopment and Autism Research News
Original Research: Open access.
“Combined Exposure to Folate and Lead during Pregnancy and Autistic-Like Behaviors among Canadian Children from the MIREC Pregnancy and Birth Cohort” by Joshua Alampi et al. Environmental Health Perspectives
Abstract
Combined Exposure to Folate and Lead during Pregnancy and Autistic-Like Behaviors among Canadian Children from the MIREC Pregnancy and Birth Cohort
Background:
Folic acid (FA) supplementation may hinder the associations between gestational exposure to certain chemicals and autism or autistic-like behaviors, but this has not been thoroughly examined for lead.
Objectives:
This study aimed to assess whether the relationship between gestational blood lead levels (BLLs) and autistic-like behaviors was influenced by gestational plasma total folate concentrations, FA supplementation, and maternal methylenetetrahydrofolate reductase (MTHFR) 677C>T genotype.
Methods:
Data from the Maternal–Infant Research on Environmental Chemicals study (2008–2011), a Canadian pregnancy and birth cohort study, was utilized. Autistic-like behaviors were documented in 601 children aged 3-4 years using the Social Responsiveness Scale-2 (SRS-2), where higher scores indicate more autistic-like behaviors. BLLs and plasma total folate concentrations were measured during the first and third trimesters of pregnancy.
Gestational FA supplementation was estimated via surveys, and maternal MTHFR 677C>T single nucleotide polymorphism (SNP) was genotyped. Associations between log2-transformed BLLs and SRS-2 scores were estimated using linear regression.
Results:
Third-trimester BLLs correlated with increased SRS-2 scores [β𝑎𝑑𝑗=3.3; 95% confidence interval (CI): 1.1, 5.5] among participants with low (<10th percentile) third-trimester plasma total folate concentrations, while null associations were observed among those in the middle category (≥10th and <80th percentiles) (p-interaction <0.001). FA supplementation also attenuated these associations.
Both folate indicators impacted first-trimester BLL-SRS-2 associations, albeit to a lesser degree. Third-trimester BLL-SRS-2 correlations were slightly stronger among participants homozygous for the T (minor) allele of the MTHFR 677C>T SNP (β𝑎𝑑𝑗=0.9; 95% CI: -1.2, 3.1) compared to those without the T allele (β𝑎𝑑𝑗=-0.3; 95% CI: -1.3, 0.7), although the difference was not statistically significant (𝑝-interaction=0.28).
Discussion:
Folate may modify the relationships between gestational lead exposure and childhood autistic-like behaviors, indicating that it mitigates the neurotoxic effects of prenatal lead exposure.