I have fibrocystic breast disease but have had no effects since I stopped drinking caffeine (over 15 years now). However, recently I started eating a high fiber cereal and all of a sudden my breasts started to hurt. All of the ingredients were benign except Aspartame.
I asked my doctor if that could be causing my problems; she said no. However, I stopped eating the cereal and no more pain. I never eat anything with Aspartame and have never had pain again.