I don’t know how much overlap there is between sugar addicts and alcoholics, but the metabolic pathway (in the liver) that metabolizes ethanol is the same one that metabolizes fructose. Ethanol and fructose also have the same effect on the brain’s reward center, the nucleus accumbens. The one difference between the two substances is that ethanol has immediate toxic effects, whereas fructose does not. The long-term toxic effects are the same.
Since a molecule of sugar (sucrose) is composed of a glucose molecule bonded to a fructose molecule, this explains the addictive nature of sugar. My understanding is that not everyone becomes addicted to sugar, just as not everyone becomes an alcoholic, but that about the same percentage—20%—of the population is vulnerable in each case. As I mentioned, I don’t know how much overlap there is between those two 20%'s, but I imagine there is quite a bit. It is standard advice to newly recovering alcoholics to use sugar to stave off cravings for alcohol, so it would be interesting to know how many alcoholics become sugar addicts because of this advice, and how many would have been sugar addicts in any case.
But addiction is a tricky subject. I worked years ago for a company where we all assumed the chairman of the board was an alcoholic, but when his doctor told him he needed to stop drinking, he did. Turned out he was just a hard drinker who loved to get drunk, but he could stop when necessary, so he wasn’t an alcoholic. Weird! A lot of the other executives were actual alcoholics, and only two that I know of ever managed to get sober.
@PSteinke1122 Ethanol can cause insulin resistance in the liver, so alcoholics can develop diabetes, whether they get sober or not. So whether the sugar use by the alcoholics you know is what caused their diabetes, or whether they were alread well on their way and the sugar only made it worse is an open question—but either way, the sugar certainly did not help! Knowing what I know now, I would certainly advise any newly-sober alcoholic to go keto.