I remember reading during my research that eating fresh-baked bread could trigger headaches. But bread in itself was not an issue, if was older than one day. So having bread in the fridge that you use for toast or sandwiches or whatever is not a problem. When I was first learning about all these headache triggers (the Do-Not-Eat list), I used to think that if I ate something in small quantities, it wouldn't effect me that much. But I learned through a lot of trial and error that sometimes it doesn't take much of a trigger to flip the switch and launch a headache. About a year ago, I was having lunch in a restaurant. I was really careful to order food that wasn't on the Do-Not-Eat list. But before my meal arrived, the waiter brought a small basket of bread. It was warm and toasty, and tasted really good on my empty stomach. I left my meal feeling okay, but shortly after I began to notice a growing headache. In typical form, the small headache increased with every passing hour. By that evening it was a full-blown migraine. I was baffled about this headache, and analyzed everything I had eaten that afternoon that might have caused this. Then I remembered how I had eaten a couple pieces of that delicious bread at lunch. Fresh-baked bread is on the Do-Not-Eat list because it's a headache trigger. If I didn't believe it before, I definitely believed it after this!
