The Devil and the Deep Blue Sea

Atlantic bluefin tuna                            © Wild Wonders of Europe/Zankl/WWF

To eat tuna, or not to eat tuna? It's a quintessential dilemma of our times. First we heard it is high in omega-3s and other anti-inflammatories. That's good. Let's eat more. Then we learned that it also has unacceptably high levels of mercury, especially the yellowfin (ahi), and that that level has been rising quickly. Not so good. Stop eating it. Now, it seems that it also has a form of selenium that mitigates mercury's dangerous effects. This antioxidant protects the fish and could protect us, as well: http://www.whfoods.com/genpage.php?tname=foodspice&dbid=112
   As far as canned tuna is concerned, however, mercury is just one of the concerns. For more than three decades, cans have been lined with something called BPA, or bisphenol A. (FYI, it's also in credit card and ATM receipts, among other things.) According to the Mayo Clinic, "Some research has shown that BPA can seep into food or beverages from containers that are made with BPA. Exposure to BPA is a concern because of possible health effects of BPA on the brain, behavior and prostate gland of fetuses, infants and children." Some companies are switching to alternative linings, but of those, only a couple will release information about what, exactly, they're using: http://www.inspirationgreen.com/index.php?q=bpa-lined-cans.html
   And here's the information that started this whole post: a list of canned tunas ranked according to the sustainability of the company's fishing practices, the company's ethics, and its fair trade practices (interactive infographic): http://www.greenpeace.org/usa/tunaguide/