Deborah Fellner must have really, really liked tuna. Between 1999 and 2004, Chicken of the Sea canned tuna was almost all she ate.

After five years of a nearly all-tuna diet, Fellner developed severe mercury poisoning, which caused “extreme physical and emotional injuries,” according to the lawsuit she subsequently filed.

Fellner sued Tri-Union Seafoods, which owns Chicken of the Sea, claiming that the company failed to warn consumers that excessive consumption of tuna could lead to mercury poisoning. The U.S. District Court in New Jersey dismissed the case, finding that Food and Drug Administration (FDA) warnings about the dangers of mercury in seafood pre-empted state law. However, in August the 3rd Circuit revived Fellner v. Tri-Union Seafoods. The appeals court found that the lower court had improperly dismissed the class action lawsuit.