Fish consumption and prenatal methylmercury exposure: Cognitive and behavioral outcomes in the main cohort at 17 years from the Seychelles child development study

Department of Pediatrics, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA.
NeuroToxicology (Impact Factor: 3.38). 08/2011; 32(6):711-7. DOI: 10.1016/j.neuro.2011.08.003
Source: PubMed

ABSTRACT People worldwide depend upon daily fish consumption as a major source of protein and other nutrients. Fish are high in nutrients essential for normal brain development, but they also contain methylmercury (MeHg), a neurotoxicant. Our studies in a population consuming fish daily have indicated no consistent pattern of adverse associations between prenatal MeHg and children's development. For some endpoints we found performance improved with increasing prenatal exposure to MeHg. Follow up studies indicate this association is related to the beneficial nutrients present in fish.

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Available from: Gary J Myers, Sep 27, 2015
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    • "Based largely on the Faroe Islands study, the Federal Drug Administration (FDA) and National Research Council (NRC) in the United States issued seafood consumption advice in 2004 recommending that women who might become pregnant, pregnant women, nursing mothers, and young children should consume no more than 12 oz of low Hg seafood per week and to avoid eating shark, swordfish, king mackerel, or tilefish because of their high MeHg levels [22]. Although meant to protect children of fish consuming populations, mothers that take this advice to the extreme of avoiding seafood altogether could actually harm their own health and diminish child neurodevelopmental outcomes [9] [10] [23]. Seafood is an important source of polyunsaturated fatty acids, which are essential for the neurodevelopment of a growing fetus [8] [9] [24]. "
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    ABSTRACT: Seafood is an important source of nutrients for fetal neurodevelopment. Most individuals are exposed to the toxic element mercury through seafood. Due to the neurotoxic effects of mercury, United States government agencies recommend no more than 340g (12oz) per week of seafood consumption during pregnancy. However, recent studies have shown that selenium, also abundant in seafood, can have protective effects against mercury toxicity. In this study, we analyzed mercury and selenium levels and selenoprotein mRNA, protein, and activity in placenta of a cohort of women in Hawaii in relation to maternal seafood consumption assessed with dietary surveys. Fish consumption resulted in differences in mercury levels in placenta and cord blood. When taken as a group, those who consumed no fish exhibited the lowest mercury levels in placenta and cord blood. However, there were numerous individuals who either had higher mercury with no fish consumption or lower mercury with high fish consumption, indicating a lack of correlation. Placental expression of selenoprotein mRNAs, proteins and enzyme activity was not statistically different in any region among the different dietary groups. While the absence of seafood consumption correlates with lower average placental and cord blood mercury levels, no strong correlations were seen between seafood consumption or its absence and the levels of either selenoproteins or selenoenzyme activity. Copyright © 2015 Elsevier GmbH. All rights reserved.
    Journal of Trace Elements in Medicine and Biology 04/2015; 30. DOI:10.1016/j.jtemb.2015.01.006 · 2.37 Impact Factor
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    • "Additionally, a study in New Zealand found decreased performance on scholastic and psychological tests associated with high prenatal MeHg exposure [6]. In contrast, in the Seychelles study cohort, higher prenatal and postnatal MeHg exposures were not associated with adverse effects in children followed out to 17 years, with beneficial associations being repeatedly noted instead [7]. Additionally, mercury exposure levels below those originally identified as potentially harmful to child and infant health have also shown negative health impacts [8]. "
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    ABSTRACT: Background: Fish consumption is common among the cultures of Hawaii, and given public health attention to mercury exposure in pregnancy, it is important to better understand patterns of fish consumption and mercury in pregnancy. This study examined the influence of maternal fish consumption during pregnancy on umbilical cord mercury (Hg) concentrations in a multiethnic cohort of women in Hawaii. Methods: This secondary analysis of a prospective cohort pilot study examined antenatal seafood consumption and neonatal outcomes in Hawaii. The first 100 eligible women who consented were enrolled. After delivery, umbilical cord blood and a dietary survey were obtained. Results: Most women (86%) consumed seafood during the month prior to delivery. Overall, 9% of women consumed more than the recommended limit of 12 ounces/week. Seafood consumption varied significantly by ethnicity and income, with 30% of poor women consuming more than the recommended limit. Seafood consumption did not vary by age or education.Umbilical cord blood Hg levels were 5 μg/L or more in 44% of women. Filipina were significantly less likely to have elevated Hg levels compared with non- Filipina (p < .05). Mercury levels did not vary by other demographic characteristics.Women reporting consumption exceeding 12 ounces fish per week were significantly more likely to have cord blood Hg levels of 5 μg/L or more, but mean Hg concentrations were not significantly higher (6.1 ± 3.3 v 5.0 ± 3.7). The odds ratio for elevated Hg, however, was significant among seafood-consumers compared with non-consumers (5.7; 95% confidence interval: 1.2, 27.1). Conclusions: Despite Environmental Protection Agency (EPA) guidelines, a significant portion of pregnant women consumed more than the recommended amount of seafood, which was associated with race and income. Further, almost half of study participants had cord blood Hg concentrations at or exceeding 5 μg/L.
    BMC Pregnancy and Childbirth 06/2014; 14(1):209. DOI:10.1186/1471-2393-14-209 · 2.19 Impact Factor
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    • "The use of computerized neuropsychological tests in epidemiological studies has been growing (Davidson et al., 2011; Forns et al., 2012; Jacobson & Jacobson, 2003; Julvez, Debes, Weihe, Choi, & Grandjean, 2010; Lam et al., 2013; Sagiv, Thurston, Bellinger, Altshul, & Korrick, 2012) since their use was first recommended (Letz, 1991). The use of these tests confers a number of advantages over classical face-to-face examination, including sensitivity and efficiency of data collection, reduction of examiner effects, and offering a supportive and friendly platform to keep up children's motivation. "
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    ABSTRACT: Computerized neuropsychological tests offered several advantages for large epidemiological studies to assess child neuropsychological development. We aimed to evaluate the psychometric properties and criterion validity of 2 computerized tests (n-back and attentional network task [ANT]) used to assess the working memory and attention function, respectively. As part of the BREATHE (BRain dEvelopment and Air polluTion ultrafine particles in scHool childrEn) project, we evaluated the neuropsychological development of 2,904 children between 7 to 9 years of age. The main outcomes of the n-back test were d' scores and hit reaction time (RT) (HRT). The outcomes measured for ANT were incorrect responses, omissions, alerting, orienting, and conflict. We also collected data of child's sex, age, school achievement, ADHD symptomatology, behavioral problems, and maternal education. We observed that the d' scores and HRT showed acceptable internal consistency, reasonable factorial structure, as well as good criterion validity and statistical dependencies. Regarding the ANT, incorrect responses, omissions, and conflict score had acceptable criterion validity although the internal consistency of the ANT was low. We strongly recommend the use of these tests in environmental epidemiological studies as valid, objective, and easy-to-apply measures of child neuropsychological development. (PsycINFO Database Record (c) 2014 APA, all rights reserved).
    Neuropsychology 05/2014; 28(4). DOI:10.1037/neu0000085 · 3.27 Impact Factor
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