Food can definitely help with LDs. Some of my best LDs occurred unexpectedly after eating fish and salad for dinner. The bottom line is that lucid dreaming depends ENTIRELY on the presence of various specific neurotransmitters in the brain, regardless of the induction technique. If the neurotransmitters are not present, LDs are not possible no matter how good your technique. It's like having a high powered car. If you don't have any gas in the tank, it ain't going nowhere.

There are a lot of psychoactive substances that produce vivid and often lucid dreams, but I agree with Luigi to keep things natural and develop a good induction technique before taking that route. If you want to experiment with something natural, however, many people report LDs after drinking chocolate milk during the night...