Balancing the benefits of n-3 polyunsaturated fatty acids and the risks of methylmercury exposure from fish consumption. Nutr Rev

Department of Occupational and Environmental Health, George Washington University School of Public Health, Washington DC, USA.
Nutrition Reviews (Impact Factor: 6.08). 09/2011; 69(9):493-508. DOI: 10.1111/j.1753-4887.2011.00415.x
Source: PubMed


Fish and shellfish are widely available foods that provide important nutrients, particularly n-3 polyunsaturated fatty acids (n-3 PUFAs), to many populations globally. These nutrients, especially docosahexaenoic acid, confer benefits to brain and visual system development in infants and reduce risks of certain forms of heart disease in adults. However, fish and shellfish can also be a major source of methylmercury (MeHg), a known neurotoxicant that is particularly harmful to fetal brain development. This review documents the latest knowledge on the risks and benefits of seafood consumption for perinatal development of infants. It is possible to choose fish species that are both high in n-3 PUFAs and low in MeHg. A framework for providing dietary advice for women of childbearing age on how to maximize the dietary intake of n-3 PUFAs while minimizing MeHg exposures is suggested.

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Available from: Chong-Huai Yan, Oct 09, 2015
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    • "Also, larger fish (swordfish, shark, king mackerel and tilefish ) that eat smaller fish, have the highest levels of MeHg due to bioaccumulation . In general concentrations of MeHg vary ~ 2 orders of magnitude between species (Mahaffey et al., 2011). Only a few species of fish could have MeHg levels of 1 ppm or greater. "
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    ABSTRACT: Exposure assessment and risk management considerations for tribal fish consumption are different than for the general U.S. population because of higher fish intake from subsistence fishing and/or from unique cultural practices. This research summarizes analyses of available data and methodologies for estimating tribal fish consumption exposures to methyl mercury (MeHg). Large MeHg fish tissue data sets from the Environmental Protections Agency's (EPA's) Office of Water, USGS's EMMMA program, and other data sources, were integrated, analyzed, and combined with fish intake (consumption) data for exposure analyses using EPA's SHEDS-Dietary model. Results were mapped with GIS tools to depict spatial distributions of the MeHg in fish tissues and fish consumption exposure patterns. Contribution analyses indicates the major sources for those exposures, such as type and length of fish, geographical distribution (water bodies), and dietary exposure patterns. Sensitivity analyses identify the key variables and exposure pathways. Our results show that MeHg exposure of tribal populations from fish are about 3 to 10 times higher than the US general population and that exposure poses potential health risks. The estimated risks would be reduced as much as 50%, especially for high percentiles, just by avoiding consumption of fish species with higher MeHg concentrations such as walleye and bowfin, even without changing total fish intake. These exposure assessment methods and tools can help inform decisions regarding meal sizes and frequency, types of fish and water bodies to avoid, and other factors to minimize exposures and potential health risks from contaminated fish on tribal lands. Published by Elsevier B.V.
    Science of The Total Environment 07/2015; 533:102-109. DOI:10.1016/j.scitotenv.2015.06.070 · 4.10 Impact Factor
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    • "Therefore, only one same-sex pup is assigned to a single experiment, although when examining sex differences some investigators treat male-female siblings as a repeated measure (Maurissen, 2010; Spyker and Spyker, 1977). Human MeHg exposure is almost exclusively through fish consumption (Mahaffey, 2004), raising a scientific and regulatory dilemma because fish are also the source of a number of important nutrients, including selenium (Se) and the n-3 polyunsaturated fatty acid, DHA (Budtz-Jorgensen et al., 2007; Mahaffey et al., 2011; Rice, 2008). Our laboratory was interested in whether nutrients found in fish influenced the impact of MeHg exposure during gestation . "
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    ABSTRACT: Events that disrupt the early development of the nervous system have lifelong, irreversible behavioral consequences. The environmental contaminant, methylmercury (MeHg), impairs neural development with effects that are manifested well into adulthood and even into aging. Noting the sensitivity of the developing brain to MeHg, the current review advances an argument that one outcome of early MeHg exposure is a distortion in the processing of reinforcing consequences that results in impaired choice, poor inhibition of prepotent responding, and perseveration on discrimination reversals (in the absence of alteration of extradimensional shifts). Neurochemical correlates include increased sensitivity to dopamine agonists and decreased sensitivity to gamma-aminobutyric acid (GABA) agonists. This leads to a hypothesis that the prefrontal cortex or dopamine neurotransmission is especially sensitive to even subtle gestational MeHg exposure and suggests that public health assessments of MeHg based on intellectual performance may underestimate the impact of MeHg in public health. Finally, those interested in modeling neural development may benefit from MeHg as an experimental model. Copyright © 2015. Published by Elsevier B.V.
    Behavioural processes 03/2015; 114(1). DOI:10.1016/j.beproc.2015.03.007 · 1.57 Impact Factor
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    • "cardiovascular disease prevention or neurodevelopmental benefits) and values are presented as an adequate intake (AI) or saturation level of PUFAs or EPA + DHA. This issue has been addressed in several previous studies (Dewailly et al., 2007; Mahafferty et al., 2011; Oken et al., 2012; Turyk et al., 2012). "
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    ABSTRACT: Fish are an easily-obtainable source of low-fat protein and fatty acids (FAs), particularly beneficial omega-3 and omega-6 polyunsaturated fatty acids (PUFAs). While data concerning FAs in marine and/or farmed fish are readily available, data regarding spatial variation in FA concentrations in wild, freshwater sport fish species are lacking. To begin addressing this data gap and to provide the general public with more comprehensive consumption advice, we analyzed 13 sport fish species from several of Wisconsin's inland and Great Lakes waters for 16 FA analytes. FA concentrations were compared between species, trophic levels, and with research previously published on freshwater species in our study. We found that fish length was positively correlated with total FA content (r = 0.617, P < 0.0001) for the whole dataset, but not for any individual species. Salmonids generally contained the highest total FAs while percids and centrarchids contained the lowest concentrations. However, diet was a better predictor of FA concentration than taxonomic family. Species that were completely or partly piscivorous contained higher PUFAs (P ≤ 0.001) than those that consumed primarily invertebrates. We also found that Wisconsin sport fish generally contained lower concentrations of monounsaturated and saturated FAs than those found in reference studies, whereas omega-3:omega-6 FA ratios and concentrations of omega-6 FAs were largely similar. Incorporating beneficial FA data into existing fish consumption advice is a challenge at this time, and it is recommended that additional FA information be obtained with the goal of quantitatively incorporating benefits into risk assessments and advisory protocols.
    Journal of Great Lakes Research 09/2014; 40(3). DOI:10.1016/j.jglr.2014.05.002 · 1.75 Impact Factor
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