By Laurine Brown, PhD, MPH
"Fish is good brain food," villagers from Bangladesh told me when I lived with them to learn their nutritional ways. As an honored guest I was served the "best" piece of fish (which to my dismay might be the head with brain and eyeballs!). "Fish is good for you" was a clear message.
Such inherent cultural wisdom is now the focus of scientific studies as the benefits of omega-3-fats take center stage. These good-for-you polyunsaturated fats are especially abundant in oily ocean fish from deep cold waters, like salmon, sardines, mackerel, tuna, and herring. Studies are informing us that upping our consumption of omega-3-fats protects our brains, hearts, reduces blood pressure, eases inflammation from rheumatoid arthritis and asthma, inhibits cancer, improves learning, and even keeps our skin moist. People who eat fish regularly have less chronic disease and live longer. Wow. What a nutritional scorecard.
But turn to the environmental literature and you're warned of the toxins in fish--mercury, PCBs, dioxins, and other pollutants of modern life. The government warns pregnant women to avoid certain fish whose toxins may harm their unborn children's developing brains and nervous systems. Eating these fish may also increase our risk for cancer (see Table 1 below). Which fish contain the most contaminants? Precisely the ones that nutritionists tell us to eat for their omega-3 goodness-- large carnivorous, oily fish. But other fish, including fresh water fish have not escaped contamination. A shocking 71% of US coastal waters and 100% of the Great Lakes and connecting waters were under consumption advisories last year, according to the EPA.
Complicating choices further, guidance from wildlife groups like Audubon Society warn us to avoid over-fished species (like shrimp and swordfish) whose populations are threatened. So, do you choose the most nutritious fish, the least polluted, the least over-fished, or give up fish altogether?
The Green Guide 2001 has compiled a handy list of "Yes" and "No" fish, attempting to synthesize these concerns (see Table 2 below). If you eat fish, protect yourself, your children (including those yet unborn), and our earth's fish populations by considering these guidelines. And if you choose to avoid fish, luckily you can stock up on omega-3's from plants like flax seeds, walnuts, pumpkin seeds, and dark leafy greens.
But ultimately, we should not be toting the "least polluted fish" lists to market. Act now to clean up our murky waters. Support groups like local Prairie Rivers Network (www.prairierivers.org) that work to protect our waterways. The pollutant fingerprints in fish that threaten our own intelligence are ours to own. For the 60% of the world's marginally-nourished people that depend on fish for protein, alternatives are few. Bangladesh villagers scraping to get by must choose what's available, polluted or not. We must find clean ways to be industrious. The rest of the creatures and plants on our tremendously industrious planet are. We can too.
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Mercury a toxic metal emitted from coal burning power plants and incineration of medical waste can permanently damage developing brains and nervous systems, particularly of fetuses and young children. |
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Polychlorinated biphenyls (PCBs) are chemicals used in electrical equipment before 1978. Now banned, they persist in air and water. PCBs in fish eaten by women before or during pregnancy can cause impaired learning and memory and lower IQ scores in their children. Adults exposed to PCBs also show learning deficits and memory loss. |
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Dioxins are exotic chemicals produced during manufacture and incineration of PVC plastic and chlorine bleaching of paper. Potent carcinogens, they also harm reproductive organs and suppress immunity. |
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Chlordane and DDT, banned but persistent insecticides, are "probably" carcinogens and suspected hormone disruptors that continue to contaminate the environment. |
