I wouldn't be quite as cavalier as Travis. Check out some TwoYubes videos of guys reviewing old MREs and you'll see plenty where several if not most of the items have gone bad - sometimes spectacularly so.
The bravest (most foolhardy) of those reviewers is
Steve1989 who boldly goes where no sane tastebud has ever gone. Some of his experiences with MRE cheese and anything with nuts will give you pause as you eye your old stock of rations, I guarantee.
