Under the Influence explains in detail about the disease aspect of alcoholism. According to it, only about 10% of the poplulation CAN become an alcoholic,because of the way these bodies metabolize alcohol when it is ingested. I found it to be really interesting reading.
I'm glad your husband has both accepted the fact that it is a disease and he has it and that he is doing what he can to stay healthy. Knowing he can not drink and then taking the action of not drinking is such a major accomplishment!!