Which Fish Should I Eat?

After reviewing numerous fish advisories, researchers conclude that we need simpler consumer guidelines and more stringent fish management policies.

Focus article photo

Margaret Karagas, co-director, Cancer Epidemiology & Chemoprevention program at Norris Cotton Cancer Center, wants to see more comprehensive, simpler fish advisory guidelines and policies that reduce contaminant levels.

As part of The Dartmouth Toxic Metals Superfund Research Program, Margaret Karagas, co-director, Cancer Epidemiology & Chemoprevention program at Norris Cotton Cancer Center, and Professor of Community and Family Medicine at the Geisel School of Medicine, contributed to a study—funded by the National Institute of Environmental Health Sciences—that reviewed fish advisories, scientific literature, and public health guidelines, seeking one, comprehensive guideline that "summarized the issue of fish consumption choice from toxicological, nutritional, ecological, and economic points of view." Such an advisory, Karagas et al concluded, does not exist.

Of the advisories available, many focus on levels of mercury (a known neurotoxin, ranking third on the ATSDR’s (Agency for Toxic Substances and Disease Registry) list of contaminants affecting human health, some on which species of fish are caught or farmed using the most ecologically sound practices, and a few on the economic aspects of the fishing industry. Almost none, according to the summary, also promote the nutritional benefits of fish.

Consumers as decision-makers: The need to weigh risks and benefits

Consumers tend to be very bad decision makers when balancing risks, the paper states. We overestimate some risks, underestimate others, and tend to focus on worst-case scenarios. As a result, most consumers are better aware of the harmful aspects of consuming fish, than of its benefits.

And there are many benefits. "Omega-3 and long-chain fatty acids," says Karagas, "prevent cardiovascular disease and improve neurodevelopment during pregnancy." Fish, generally low in fat and high in protein, offers a winning combination.

Karagas advocates not only for a more comprehensive and simpler fish advisory guideline, but also new fishery management practices and federal policies aimed at reducing contaminant levels. (Many of the sources of mercury are coming from air pollution.)

For now, Karagas hopes consumers will become aware of the advisories available at many grocery stores and on-line, and realize the need to weigh risk against benefit. "The consumption advice that people are currently getting," Karagas notes, "can be very confusing. We need a holistic recommendation that the public can understand, interpret, and carry out."

How contaminates get into fish

Want to learn more? Watch this 10-minute movie by Dartmouth, which explains how mercury enters the seafood we eat, why eating low-mercury fish is important for good health, and the need to keep mercury out of the environment.

October 15, 2012