biochemistry - Decreasing the alcohol proof and faster in hangover, why?

My russian friend says that the USSR agents used/use the trick that they offered the victim first vodka and then last wine.

I have noted that this puts you faster to hangover: decreasing the alcohol proof. Some people lose their motor function immediately and some their memory only.

Why does a decrease in the alcohol proof cause you a) faster intoxication and b) faster hangover?

Probably the change in the concentration of alcohol inside cells of brain tissue affects some parts of your brain like the cerebellum. I would like to have an explanation in Biochemistry.

Is there any truth in my friend's argument?

Answer

I would argue that your central point is intrinsically flawed. Your claim is that starting at a high alcohol percentage, then gradually decreasing alcohol content, gets you intoxicated faster. @nico is correct that you will get drunk faster this way (more alcohol sooner rather than later, so this is trivial). If we allow only one variable to change, the alcohol content (and therefore the water content), then the first drink is the most potent, and each drink afterwards is getting progressively more dilute, then this implies you are able to rehydrate better the more you drink. This argues exactly opposite to your claim.

Since you offered up the example of vodka to wine, this introduces two new important aspects: fermentation impurities and sugar content. Vodka is distilled and relatively pure, so it offers little in addition to alcohol and therefore easy to process by the liver. Scotchs and whiskeys are low sugar, higher impurities, and so would be a bit more troubling to filter and process. As you move down to wine, impurities rise and sugar content is much higher. This added sugar load dehydrates faster as well as causes a cascade of hormonal changes that are more immediately troubling than the alcohol. Beer would generally be the extreme end of the impurity and sugar continuum.

Since you bring up the USSR and the KGB, I imagine that if they did stick to this regimen of interrogation, it could be more effective by power of suggestion. The victim believes they are more intoxicated than they are, and perhaps more likely to offer up their secrets.