Very nice post, addictions are very complex physical and psychological phenomenon. It wouldn't surprise me that our reward complex for sugars (which are addicting!) would be involved in setting us up for alcohol or other addictions. In essence when eating sweets we are priming these reward pathways to be responsive to other pleasure molecules like alcohol.

However as you point out, its not just these reward pathways, there are a variety of other mechanisms by which the body craves this sort of stuff.

Interesting :)