I agree that the question as asked is off-topic, though I disagree with the vehemence that our mods seem to be arguing about how it is so clearly off-topic. I also have spent the past few years trying to really understand what our community policing is regarding the difference between "health effects" vs. "food safety" vs. other random effects. I disagree that there is a clear and unambiguous line between "health topics" and everything else, with "food safety" being the only exception.
This question as asked is off-topic for the simple reason that it's trying to ask about biology. I agree. On the other hand, I do not think we should out-of-hand dismiss very similar questions as "off-topic" if they are phrased in a way that is relevant to cooking and serving food. I'm sure my response here may be modded down to oblivion -- go ahead if you feel that necessary, but I hope you'll at least note some of the problems in the inconsistency about this boundary that I'd like to draw attention to.
To get to the alternative questions I was mentioning -- to me, it's NOT a priori clear that we should close questions like this as off-topic:
I'm a sommelier. We've been introducing longer paired flights of wine with dishes of many courses, and due to cutbacks in our budget, I've been trying out cheaper paired alcohol options (but still very lovely and workable, from my perspective). I've heard it said that cheaper booze often causes more hangovers, and I don't want our patrons going home, getting a hangover, and thinking that we served them junk. Is there anything I can look for when choosing wines for a part of a tasting menu that would lessen the possibility of a "hangover" effect?
Hi. I'm hosting a dinner party, and I have friends who like to drink a lot. I don't want to skimp on the alcohol cost, but to buy in quantity, I may need to sacrifice quality. On the other hand, I don't want my guests to go home with hangovers. Is there something I should look for in purchasing less expensive booze to avoid this?
From my perspective, such questions should still likely be closed because they are too broad and unanswerable within current science. But they shouldn't be off-topic on a site about food culture where such concerns are a legitimate part of planning a meal or serving beverages at a party. I think such a question is really quite different from a broad "nutrition" question, since no one's asking for a way to prevent heart disease or avoid making their spouse fat over a period of months or whatever. This is about an acute and specific response to food/beverage intake which is generally as undesirable as food poisoning (if not more so).
Now, you may say, "Food safety is our only exception. This isn't a food safety issue." But that's not true. We make exceptions for:
Allergies. Granted, most of these questions are of the form, "My guest is allergic to X. How can I make a substitution to avoid X in a dish." But there are also questions about whether various things will "set off" an allergy (like here and here), or why some allergies may "overlap" in a single person (like here). The former questions about "setting off an allergy" are clearly not culinary in nature -- since they primarily have to do with physiological effects -- but I gather they haven't been closed because of the practical culinary application necessary to prevent acute illness. Is it really necessary to remove all wheat from my house for someone with Celiac Disease? That's not someone you find on a food safety website, but I agree it should be potentially on-topic here.
Other physiological effects. There are questions about indigestion (although "food safety" is mentioned in the question, it's really about "getting a bellyache," etc.) and flatulence (see here, here, and here for questions that are solely about the physiological impact of food on avoiding flatulence, though there are many other questions which invoke that as a concern in the question).
Then there's the somewhat recent question about getting mysterious headaches while cooking, which no one even seemed to flag as potentially off-topic. That's despite the fact that it has nothing to do directly with food and is solely about a physiological effect that the OP was only speculating might have to do with cooking.
There's even at least one question from the past few years about the physiology of getting drunk, with questionable culinary connection.
I want to be clear that I'm NOT at ALL criticizing mods or the policing of such things, nor am I implying that we should close all of these questions. I'm okay with these questions, because I think they all have to do with the larger context of cooking and direct physiological effects of preparing and serving food.
Hangovers, to my mind, are just as clearly connected and as undesirable an effect as flatulence is to beans. In fact, I have trouble coming up with anything else that I'd put into that category -- alcohol and beans are two things that lots of people around the world eat, and they both have a specific undesirable reaction that most people want to avoid. If there's a way I could select, prepare, or cook beans to avoid gas, I think that should be on-topic here. And if there's a way that I could select, produce, or serve alcoholic beverages that would avoid hangovers, I similarly think that would be of great interest to the broad culinary vision of this community.
The problem, of course, is that most hangover research is crap so far. Just about every study claiming they've found the magical ingredient is contradicted or heavily qualified by another study. And many studies are small, without adequate controls, etc. (This is a huge problem with alcohol studies -- you can't really have a legitimate control group when the vast majority people will realize they've been given a placebo rather than enough alcohol to cause a hangover.)
And what people don't want to admit is that most of the hangover effects are just withdrawal symptoms after a drug leaves your system, pure and simple. Drink less or avoid a heavy concentration at once, and the effects will be less. So the very idea that there is a "magical way" to prevent ALL hangovers by avoiding certain chemicals in certain drinks seems crazy -- if there were such a magical formula, why would people still be making wine or other booze that has those things in it?
Nevertheless, there have been headlines in the past couple years with scientists claiming they could produce an alcoholic beverage which would NOT cause hangovers. I don't believe this is likely, but if it proves to be true, then I think a question asking about how to find similar beverages SHOULD be on-topic here. Regardless of whether someone knows the specific thing in alcoholic beverages that causes hangovers, they may want to avoid them or want to avoid serving guests those things, just as someone may want to ask how to avoid flatulence from beans without knowing it is caused by oligosaccharides and whatnot.
Again, I'm NOT arguing the present question under discussion should be re-opened. Nor am I really arguing that any hangover questions should currently be allowed, because I just think the science is still too confusing. But if we start seeing actual "designer booze" in the next few years that significantly and verifiably reduces hangover risk, or if scientists do finally come up with a list of "these four things definitely cause 85% of hangovers; avoid booze with them, and you'll be much better off," I don't think we should dismiss a question that's trying to plan a dinner party and avoid bad drinks as "off-topic" on the nutrition/health rationale. I don't think it's so clearly off-topic when considered in light of some of the questions cited above as has been suggested so far.
And if nothing else, hangovers are a fundamental part of culinary and foodie culture, yet as undesirable as a fallen souffle. For that reason alone, I think there's a strong argument that a specific and pointed question with a known verifiable answer about food/beverage choices to avoid hangovers might be allowed (if not now, at some point in the future).