Smells Fishy: Toxins in Your Seafood

Feel like freaking yourself out today? Google “toxins in fish,” and just scan the first page of hits alone. Outbreaks, diabetes, unknown poisons, heavy metals, pesticides… aye aye aye! Who knew fish could be so scary?

As a pescetarian (a person who eats seafood, but no other meat products), the issue of toxins in fish is important to me, so I’ve been studying up. Here are a few things I’ve learned:

1. Large, top-of-the-food-chain fish such as tuna and swordfish often contain high levels of mercury, since their long lives allow them plenty of time to consume lots of smaller fish, which often contain methylmercury (a naturally occurring substance created when microorganisms munch on ocean sediment). Over time, methylmercury builds up in predator fish and is then transferred into our bodies when we sit down to a tuna sandwich. Children and pregnant women are especially prone to mercury’s detrimental effects — among them, seizures, brain damage and learning disabilities — so those populations are urged to eat only small amounts of certain fish species. This wallet-sized card from the Natural Resources Defense Council is helpful for determining which types of fish are safe to eat, and in what quantities.
2. Other toxins sometimes found in fish include polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT), polybrominated diphenyl ethers (PBDEs) and other halogenated hydrocarbons, some of which have been linked to breast cancer, diabetes, liver damage and nervous system disorders.
3. As if those things weren’t bad enough, animal waste from factory farms has been known to seep into waterways, polluting fish with E. coli and other bacteria that can be passed on to humans.

Gross! As much as I love the taste of fish, and the essential fatty acids they provide, bacteria, mercury poisoning and toxicity sure put a damper on things. I always try to eat fish that’s sustainable, but from now on I’m also going to try harder to buy and eat fish that’s low in toxins. Living in a big city, I breathe in enough toxins every day as it is. I don’t need my diet to make things worse.