I dunno about nightmares necessarily but I do have more dreams when I eat cheese. My imagination goes haywire! I haven't had any nightmares about a huge chunk of killer cheese chasing me yet. Ooooh, that'd be scary!! :o\
I watched a programme last week that says that contrary to popular belief, cheese does not affect your dreaming patterns or how you remember them, and is actually a good thing to eat before going to bed at night.
My friend conducted an experiment where she and a friend ate different types of cheses and compared the craziness of their dreams. Blue Cambazola(sp?) Brie was found to be the most effective at conjuring up crazy dreams they dubbed 'brieams'.
It's *kinda* scientific!
cheese takes a long time to digest. While you are digesting, your brain is active. If you are digesting while sleeping, although you are asleep, your brain is still in overdrive. Hence the crazy dreams. They're not always nightmares, just vivid dreams. The same thing will happen if you eat something heavy and then go to sleep.
One night I listened to Steps, S Club 7, Chesney Hawkes and Take That before going to bed and had the most horrible dreams so I guess too much cheese really does give you nightmares.