Summary: A study has shown that folic acid supplementation during pregnancy may reduce the link between maternal blood lead levels and autistic-like behaviors in children. By examining data from pregnant women and their toddlers, researchers found stronger associations between lead exposure and autism traits in cases of low folic acid intake.
Adequate folic acid intake of 0.4 mg daily appears to lessen these neurotoxic effects, but no added benefits were seen with higher dosages. This finding 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 seen in cases of low folic acid intake.
- High levels of folic acid (>1.0 mg/day) didn’t show extra protective effects.
Source: Simon Fraser University
A new study by Simon Fraser University researchers has found that folate may weaken the link between blood-lead levels in pregnant women and autistic-like behaviours in their children.
Researchers from SFU’s Faculty of Health Sciences, led by PhD candidate Joshua Alampi, published the study in the journal Environmental Health Perspectives.
“Folic acid supplementation during pregnancy has numerous benefits to child health, especially brain development,” says Alampi. “Our study suggests that adequate folic acid supplementation mitigates the neurotoxic effects of lead.”
The SFU-led study is the first to observe that adequate folic acid supplementation may reduce the risk between gestational lead exposure and autism. It found that associations between blood lead levels and autistic-like behaviours in toddlers were stronger among pregnant women with less than 0.4 milligrams per day of folic acid supplementation.
Folate and folic acid, a synthetic version of folate found in fortified food, have long been established as a beneficial nutrient during pregnancy. Folate consumption plays a key role in brain development and prevents neural tube defects.
Previous studies have found that the associations between autism and exposure to pesticides, air pollutants and phthalates (chemicals commonly found in soft plastics) during pregnancy tend to be stronger when folic acid supplementation is low.
The team used data collected during 2008-2011 from 2,000 Canadian women enrolled in the MIREC study (Mother-Infant Research on Environmental Chemicals). The MIREC team measured blood-lead levels collected during first and third trimesters and surveyed participants to quantify their folic acid supplementation.
Children born in this cohort study were assessed at ages three or four using the Social Responsiveness Scale (SRS), a common caregiver-reported tool that documents autistic-like behaviours in toddlers.
However, researchers also found that high folic acid supplementation (> 1.0 milligram per day) did not appear to have any extra benefit for mitigating the neurotoxic effects of lead exposure.
“The study’s finding aligns with Health Canada’s recommendation that all people who are pregnant, lactating, or could become pregnant, should take a daily multivitamin containing 0.4 milligrams of folic acid.”
About this neurodevelopment and autism research news
Author: Jeff Hodson
Source: Simon Fraser University
Contact: Jeff Hodson – Simon Fraser University
Image: The image is credited to Neuroscience 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 attenuate the associations between gestational exposure to certain chemicals and autism or autistic-like behaviors, but to our knowledge, this has not been assessed for lead.
Objectives:
We examined whether the relationship between gestational blood-lead levels (BLLs) and autistic-like behaviors was modified by gestational plasma total folate concentrations, FA supplementation, and maternal methylenetetrahydrofolate reductase (MTHFR) 677C>T genotype.
Methods:
We used data from the Maternal–Infant Research on Environmental Chemicals study (2008–2011), a Canadian pregnancy and birth cohort study. Childhood autistic-like behaviors were documented in 601 children 3–4 y of age with the Social Responsiveness Scale-2 (SRS-2), where higher scores denote more autistic-like behaviors. We measured BLLs and plasma total folate concentrations during the first and third trimesters of pregnancy.
We also estimated gestational FA supplementation via surveys and genotyped the maternal MTHFR 677C>T single nucleotide polymorphism (SNP). We estimated the confounder-adjusted associations between log2-transformed BLLs and SRS-2 scores by two indicators of folate exposure and maternal MTHFR 677C>T genotype using linear regression.
Results:
Third-trimester BLLs were associated 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, but BLL-SRS-2 associations were null (β𝑎𝑑𝑗=−0.3; 95% CI: −1.2, 0.5) among those in the middle category (≥10th and <80th percentiles) (p-interaction <0.001). FA supplementation also attenuated these associations.
Both folate indicators modified first-trimester BLL-SRS-2 associations, but to a lesser extent. Third-trimester BLL-SRS-2 associations were slightly stronger among participants who were homozygous for the T (minor) allele of the MTHFR 677C>T SNP (β𝑎𝑑𝑗=0.9; 95% CI: −1.2, 3.1) than those without the T allele (β𝑎𝑑𝑗=−0.3; 95% CI: −1.3, 0.7), but the difference was not statistically significant (𝑝-interaction=0.28).
Discussion:
Folate may modify the associations between gestational lead exposure and childhood autistic-like behaviors, suggesting that it mitigates the neurotoxic effects of prenatal lead exposure.
