y, and the greatest energy drainer is mental and emotional stress, which I believe to be the root cause of all illness. Stress is one of the major elements that can erode energy to such a large and permanent extent that the immune system loses all possibility of functioning at an optimum level. The Only Answer to Cancer is a book of hope, and I want you to understand that there is always hope, no matter how bad your health situation is right now. Your journey to ultimate health begins today!