Mercury, selenium and fish oils in marine food webs and implications for human health

Abstract

Humans who eat fish are exposed to mixtures of healthful nutrients and harmful contaminants that are influenced by environmental and ecological factors. Marine fisheries are composed of a multitude of species with varying life histories, and harvested in oceans, coastal waters and estuaries where environmental and ecological conditions determine fish exposure to both nutrients and contaminants. Many of these nutrients and contaminants are thought to influence similar health outcomes (i.e., neurological, cardiovascular, immunological systems). Therefore, our understanding of the risks and benefits of consuming seafood require balanced assessments of contaminants and nutrients found in fish and shellfish. In this paper, we review some of the reported benefits of fish consumption with a focus on the potential hazards of mercury exposure, and compare the environmental variability of fish oils, selenium and mercury in fish. A major scientific gap identified is that fish tissue concentrations are rarely measured for both contaminants and nutrients across a range of species and geographic regions. Interpreting the implications of seafood for human health will require a better understanding of these multiple exposures, particularly as environmental conditions in the oceans change.

Mercury exposure and risk of cardiovascular disease: a nested case-control study in the PREDIMED (PREvention with MEDiterranean Diet) study

“…Thus, we could not obtain direct measurements of association between type of fish intake and toenail mercury concentrations. Seafood varies in mercury content [49], although mercury content of popular Spanish seafood have relatively consistent mercury levels [50]. Lastly, our sample size is small and many models are adjusted for many covariates, thus limiting our power, particularly when we adjust rather than match for sex and age in unconditional logistic regression models.…”

Using Domestic and Free-Ranging Arctic Canid Models for Environmental Molecular Toxicology Research

“…In other words, it is important to consider that changes in physiology associated with Hg exposure in a laboratory setting might be absent in a fish-based diet exposure due to protective nutrients collocated in fish (i.e., selenium and polyunsaturated fatty acids). 43 …”

Past, Present, and Future of Mercury Pollution Issues

“…3.1 for scientific names of species that are assigned numbers from 1 to 25 in parentheses. (Gribble et al 2016). That is, the positive association of mercury with neurodevelopment was found in four of nine populations, while five populations did not show any evidence (Kjellström et al 1989;Davidson et al 1998;Myers et al 2003;Valent et al 2013;Tatsuta et al 2014;Strain et al 2015).…”

“…Gribble et al (2016) summarized major cohort studies examining early-life mercury exposure and neurodevelopment in children. Four of nine populations showed the positive association.…”