Yeah, aluminum is even for sale for ingesting, as 'alum' and I heard that it is used in making processed cheese and other food items. I'm thinking it is one of those things that SHOULD have been banned from certain uses, decades ago. I'd vote for it to be banned from food products and cooking items/cooking bags. As for the foil, I have probably used it one time in many years for cooking, to cover a large turkey that my roaster lid wouldn't cover. I do use it as a cover for non-cooking, like to transport pies. But I snarl, every time that I do these little things, even.
check it out and make up your own mind. If/when you see the foil discolored, please do think about this.
It is worse with higher acid food, like tomato, I would think.