Cabbage is really healthy for you in moderation due to the good antioxidants, vitamins such as vitamin K and other nutrients.
Cabbage can help to prevent dementia and boost your immune system and protect your body from many diseases including cancer as well as boosting your energy levels.
But when you do consume too much cabbage it can lead to bloating, stomach pain and possible diarrhea.
Other than that nothing harmful will happen to your health by eating too much cabbage but if you're experiencing stomach pain, bloating or diarrhea after eating too much cabbage then you should slow down on the consumption of the cabbage.
But eating cabbage is moderation will actually improve your health.