Fungal toxins in corn may be the reason for neural tube defects outbreak in the Rio Grande Valley during the early 1990's.
The study published in the on line journal Environmental Health Perspectives suggests that corn and its products that have been infected by fungal toxins might give rise to neural tube defects (NTD), if consumed during the first trimester of pregnancy.
Talking about "Neural tube defects" these are embryonic defects of the brain and spinal cord resulting from failure of the neural tube to close.
The aim of the study was to investigate whether tortillas contaminated with fumonisin caused the neural tube defects outbreak (1990-1991) in Cameron County, Texas.
The human outbreak of neural tube defects occurred during the same crop year as epizootics, attributed to exposure to fumonisin, a mycotoxin produced by the molds Fusarium verticillioides that often contaminates corn, according to the article.
The type of the study was population-based case control study, in which the researchers estimated the exposure to fumonisins during the first trimester from a postpartum sphinganine:shingosine ratio (sa:so ratio), a marker for fumonisin exposure measured in maternal serum, and corn tortilla intake based on the maternal recall.
225 Mexican-American women with NTD-affected pregnancies and 378 Mexican-American women with healthy births were the study group. Among them, 184 NTD-affected women and 225 control women participated in an interview. Among the interviewed, 163 case women and 189 control women provided blood samples for the sa:so ratio test.
The results based on the study was that those who consumed 301 to 400 tortillas during the first trimester were more than twice likely to have NTD-affected pregnancies compared to those who consumed 100 or less. Additionally, 401-800 tortillas during the first trimester were associated with a slightly decreased risk of NTD.
Based on the postpartum sa:so ratio, increased exposure to fumonisins was associated with an increased risk of NTD.
The results of the study suggest the risk of neural tube defects increases as exposure to fumonisins increases to a threshold, at which fetal death can be caused.
Stacey A. Missmer and colleagues at Harvard School of Public Health, Boston, MA, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, Texas Department of State Health Services, Austin, TX, and Boston University School of Public Health, Boston, MA, and the Medical Institute, Austin, TX were the researchers who took upon themselves the mantle if the study and proved a thought hypothesis. They established the link between corn consumption and NTD outbreak linking it to fungi toxins.