[ I know that I can't eat anything with oatmeal, or any kind of fish/sea food,
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I had a friend who worked with me in the hospital, who was very allergic to sea foods. She fixed her own sandwiches and instead of tuna she used chicken breast, ground up. Mayo, lettuce and tomato, on good bread. One day she had such a terrible reaction that she was in ER for hours before being able to go home.
At about that same time, my late DH, a nurseryman, was reading to me some new (1980s) research on how to grow tomatoes in colder weather and with more salt in the dirt. They were trying to put cold weather fish DNA into the tomatoes and growing them near the ocean. I've never heard anything more of that, but it would be relatively easy to get this DNA into the general population of commercial tomatoes. Wind can carry pollen for many miles, as can humans. Even someone liking the looks of a tomato plant can take cuttings and grow them at home, many miles away. And save and share the resulting seeds!! That's why we fear new plants coming into this country, it's way too easy to get what we don't want started. Almost impossible to kill them all after they get started.
I told this to my friend and she reluctantly crossed tomatoes off her diet plan.
I'd suggest you try to find out what was put into this cake, because some of the dyes, Red Dye number 5 is in most of them but some I'm sure is not required to be on the printed list.