A “major scientific gap” exists in the understanding of the risks and benefits of eating seafood, according to a Dartmouth College researcher and her collaborators.
Celia Chen, a research professor of biological sciences and a project leader in Dartmouth's Toxic Metals Superfund Research Program, and her research team have found that when studying fish, fish tissue is seldom measured for concentrations of both harmful contaminants and healthful nutrients. A more complete understanding of these multiple exposures will be necessary for interpreting the implications of seafood for human health moving forward, especially as the environment and ocean conditions change, said the research team.
"The factors affecting marine fish may be altered by climate change impacts such as ocean warming and acidification, by increases in precipitation and nutrient loading and by changes in contaminant sources," Chen said. "Together, these changes indicate a need for continued research on fish nutrients and contaminants in marine and biomedical science as well as ongoing communication between these disciplines."
For their study, the research team looked to human exposure of fish oils, selenium, mercury and methylmercury; data from 10 studies carried out over two years involving 63 fish species was also scrutinized by the team. What they ultimately discovered was that “our ability to estimate the risks and benefits of seafood consumption is hampered by the common practice of separately studying contaminants or nutrients in fish.” Moreover, a tremendous variability between and within fish species in their mercury and fatty acid concentrations was observed – this inevitably complicates how epidemiological studies on seafood health implications are interpreted, said Chen and her collaborators.
Future studies that seek to examine the human health benefits of fish and seafood will require “greater understanding of exposures to both fish contaminants and nutrients as well as the environmental and ecological drivers that control uptake of contaminants and nutrients in marine food webs,” concluded the team.
The study appears in the latest edition of the Journal of the Marine Biology Association of the United Kingdom.
