You wouldn't think that something as mundane as making a sandwich for my daughters on a weekend afternoon would be loaded with controversy, but it is. You see, my daughters love tuna fish sandwiches. Easy enough, right? We all grew up on sandwiches made of canned white tuna mixed with mayonnaise and served with a pickle. Yet although this quintessential American lunch may seem benign, it's something I refuse to serve my children. The tuna fish sandwich we all grew up on is now too controversial, and potentially dangerous, for my daughters to eat.