The science of avoiding a hangover

One festive tipple too many? Hangovers can leave us with headaches, nausea and a general feeling of bitter regret. But perhaps some simple chemistry can help us to enjoy a drink or two without feeling awful the next day. John Emsley, author of Chemistry at Home, gave his top tips to Georgia Mills, starting with how alcohol actually gets us drunk...

John - It makes you drunk because the body's treating it as a toxin - it really doesn't want this.  I mean we get a little bit of alcohol from our intestines every day and the body wants to get rid of it, but if we give it a lot then some rather nice things happen because some of the alcohol replaces the water along the central nervous system.  So we feel more relaxed, less inhibited, so we can say things we wouldn't normally say, and it can all be jolly friendly and wonderful, which is what you want at Christmas of course.

Georgia - And then the less wonderful part comes - the hangover.  Why do we get hangovers?

John - Well, the trouble is of course, as I say, the body regards alcohol as a toxin, it wants to get rid of it and it's got an enzyme called alcohol dehydrogenase, which attacks the alcohol and turns it into something called acetaldehyde, and that's a really nasty chemical which then produces all the symptoms of a hangover: headache, nausea, tight chestedness, feeling sick.  So when we wake up in the morning, when the level of that is quite high, we've got a typical hangover.

Georgia - I know the feeling well.  But is there a way, short of not drinking anything, that we can avoid a hangover.

John - Well, a few things.  First of all, don't drink on an empty stomach.  So, if you're going out for the evening, you're going to go to something, have a glass of milk or something like that so you're not drinking on an empty stomach.  And then during the course of the evening, whatever you're drinking, perhaps occasionally have a soft drink or something with no alcohol in it, because you've got to try and counteract the dehydration that's going to occur which will make the hangover worse.

Georgia - And what's the ultimate hangover cure in the morning would you say?

John - Well, when you get to the morning, the only thing you can do is grin and bear it until the level of acetaldehyde has gone down which will be about midday.  So you can help that though by having a proper breakfast, and the best think you can have is, say something like toast and honey because then you're supplying the body with things that have become depleted as it's been attacking the acetaldehyde, so it will do that more efficiently.

Georgia - Why are some drink worse than others at making you hungover?  I'm thinking now especially of port which, essentially, is a hangover in a bottle.

John - Yes, I know what you mean.  The thing is, of course, some drinks, especially coloured drinks, contain lots of other things like polyphenols which, again, the body doesn't really want.  I mean these are quite useful in some respects but not particularly good in terms of the body dealing with them.  And, of course, the darker the drink the more you're likely to have these other unwanted chemicals.  Acrylene is one, for example, that's really nasty.  Its low levels in most drinks but in the coloured drink it's a slightly higher level of it, and so avoid the coloured drinks.  The best thing is to stick to gin, of course.

Georgia - Oh well.  I'm happy to do that.

John - Well the reason for that, of course, that's doubly or triplely distilled alcohol and I know it's distilled from various herbs and spices, so you get a little bit of a flavour with it but, basically, it's quite a clean drink.  And, of course, if you have that with something like tonic, you dilute it (perhaps one part gin to three parts tonic or something), then you're getting a fairly balanced drink then which isn't going to leave you too dehydrated.  Because the think about alcohol is it affects various organs of the body and it makes it easier for the body to get rid of water (as we always know), and that, of course, is going to lead to dehydration which is going to make the hangover worse in the morning.  The best tip I always give people is, before you go out drinking, put a pint of water on the table in the kitchen or by your bed and drink that before you go to sleep.

Georgia - Is there any truth to the old saying "hair of the dog that bit you?"  Can drinking the morning cure your hangover?

John - It may help a little bit, especially if you have a very dilute drink, but I think if you find that you always get that effect in a morning then it's a sign that you're getting towards alcoholism.  So a "hair of the dog" might work if you're in that state but, otherwise, it's better to have just a non-alcoholic drink in the morning.

Georgia - And how long does it take to process alcohol, both in terms of getting rid of a hangover and in terms of how long it takes you to sober up?

John - Well, it takes the body about an hour to get of one unit which is ten grams of alcohol, so a small glass of wine or half a pint of beer is one unit.  But, of course, the thing is once you start drinking, you perhaps tend to drink more than you realise and, of course, when you stop drinking, it's going to be longer and longer before you can safely have a level which would allow you to do something like driving.