Can folate intake reduce arsenic toxicity?
Arsenic-contaminated groundwater is a global environmental health concern. Inorganic arsenic is a known carcinogen, and epidemiologic studies suggest that persons with impaired arsenic metabolism are at increased risk for certain cancers, including skin and bladder carcinoma. Arsenic metabolism involves methylation to monomethylarsonic acid and dimethylarsinic acid (DMA) by a folate-dependent process. Persons possessing polymorphisms in certain genes involved in folate metabolism excrete a lower proportion of urinary arsenic as DMA, which may influence susceptibility to arsenic toxicity. A double-blind placebo-controlled trial in a population with low plasma folate observed that after 12 weeks of folic acid supplementation, the proportion of total urinary arsenic excreted as DMA increased and blood arsenic concentration decreased, suggesting an improvement in arsenic metabolism. Although no studies have directly shown that high folate intake reduces the risk of arsenic toxicity, these findings provide evidence to support an interaction between folate and arsenic metabolism.
Kile
Molly L
ML
Department of Environmental Health, Harvard School of Public Health, 665 Huntington Avenue, Boston, Massachsetts, USA.
Ronnenberg
Alayne G
AG
D001151:Arsenic / Q000378:metabolism* / Q000652:urine; D020261:Arsenic Poisoning / Q000188:drug therapy*; D004781:Environmental Exposure; D005492:Folic Acid / Q000378:metabolism* / Q000627:therapeutic use*; D006801:Humans; D008745:Methylation / Q000187:drug effects*; D009369:Neoplasms / Q000139:chemically induced; D012307:Risk Factors; D014803:Vitamin B Complex / Q000378:metabolism / Q000627:therapeutic use
D014803:Vitamin B Complex; D005492:Folic Acid; D001151:Arsenic