I was shocked to find GMO soy in my canned tuna fish. Apparently, it’s not that unusual to have soy in tuna. How do I know it’s GMO soy? If the label doesn’t have the certified organic symbol, or clarify that the soy is non-GMO, you can assume that the soy is genetically modified. Luckily, there are brands that don’t have any soy, just check the label to be sure.