They say cabbage heals ulcers and prevents cancer. Here is one great site for finding information: The World’s Healthiest Foods: Cabbage.
Some people drink cabbage juice (the fresh juice is sweet, with a bit if an edge). If you buy a good WIDE MOUTHED juicer, the process is quite easy.
Others go on cabbage soup diets, but I am sure that you would want to investigate its health effects, since boiling the cabbage destroys nutrients and since protein is an important component of all healthy dietary regimes.