Superfund Research Program
Nutritional Influences on Blood Arsenic, Arsenic Methylation and Cognitive Function in Children
Final Progress Reports
Aims 1 and 2 of the Nutritional Influences on Blood Arsenic, Arsenic Methylation and Cognitive Function in Children Project were to conduct a RCT of folate+B12 supplementation in eight- to ten-year-old children to determine if this nutritional intervention can increase arsenic methylation and lower blood arsenic. In 2019, the team completed enrollment and follow up of all 240 participants. Biological samples from this RCT were shipped to Columbia University. All analyses of plasma folate and B12 and RBC folate are completed as are the urinary and blood arsenic and urinary and blood arsenic metabolites. Analyses currently underway include measures of plasma homocysteine and water arsenic. Should supplementation of folate+B12 prove to increase arsenic methylation and lower blood arsenic in children, this will have substantial implications for a low-cost, low-risk intervention for children as has been previously shown in adults.
For Aim 3, using data from 405 American Indians from the Strong Heart Family Study (SHFS), the team evaluated the effects of dietary intake of one-carbon metabolism (OCM) related micronutrients on arsenic methylation capacity in a US population exposed to moderate arsenic levels. Arsenic metabolism was measured as the percentages of each metabolite, i.e., inorganic arsenic (iAs), monomethylarsonate (MMA), and dimethylarsenate (DMA) in urine. Higher intakes of vitamins B2 and B6 were associated with modest but significant decreases in percentage of iAs and MMA and increases in percentage of DMA. These findings suggest higher dietary intake of nutrients that influence OCM may increase arsenic metabolism in populations with moderate arsenic exposure. While arsenic remediation should remain the top priority, study findings indicating a positive influence of OCM nutrients on arsenic metabolism suggest that nutritional interventions may serve as low-cost low-risk approach to increase arsenic metabolism and thereby lower blood arsenic concentrations.