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Does mixing alcoholic drinks cause hangovers?


Many people believe that mixingwine, beer and spirits causes nasty hangovers. Are they right? Claudia Hammondstudies the evidence


"Grape or grain, but never the twain." So runsthe old folk wisdom that advises against drinking wine or beer on the samenight. It is far from uncommon to hear people who have woken up feeling sick,dehydrated and with a splitting headache blaming their hangovers on havingunwisely mixed their drinks.


Then there are the theories about the order in which toconsume different tipples. One version suggests: "Wine before beer and you'llfeel queer. Beer before wine and you'll feel fine." Or is it the other wayround? After a couple of drinks it's not always easy to remember. All of whichbegs the question of how reliable these sayings are. Is there any evidencebeyond the anecdotal that drinking wine followed by beer or vice versa makeshangovers worse?


A review of previous research published in 2000 confirmsthat the causes of the main symptoms of hangovers are dehydration, changes inthe levels of hormones such as aldosterone and cortisol, and the toxic effectsof alcohol itself. In addition there's evidence that the immune system isdisrupted and that this could be the cause of the headache, the nausea and thefatigue.


The first of the two main ingredients of a drink that affect the severity of ahangover is obvious. The higher the alcohol content, and the faster you drinkit, the worse the hangover. This is however just an average. The same quantityof alcohol does not always result in the same severity of hangover. Many reportthat they don't get hangovers and no one quite knows why. In a study of youngDanes on holiday, almost a third of those who consumed at least 12 units ofalcohol (roughly equivalent to four pints of lager or four 250ml glasses ofwine) avoided hangovers.


Many drinkers report that they don't get hangovers at all,but it's unclear why (Thinkstock)


Mixing drinks needn't necessarily increase the overallamount of alcohol consumed, but it may do with cocktails. If combining three orfour measures of spirits alongside other ingredients, a throbbing head and drythroat is probably just the result of consuming more alcohol in total.


Beyond the ethanol that triggers intoxication, the otherkey ingredients that affect hangovers are what the beverage industry callscongeners. These are the other substances produced during fermentation, such asacetone, acetaldehyde, fusel oil and the best-known, tannins, which give darkerdrinks their colour and part of their flavour. Bourbon whisky, for example,contains 37 times the quantity of congeners as vodka.


To find out the effect of these substances on hangoverseverity, researchers in the USrecruited university students who were regular drinkers, without alcoholproblems. On different nights they were given either bourbon and cola, vodkaand cola or a placebo which consisted of cola mixed with tonic, with a fewdrops of either bourbon or vodka to make it taste similar to the real stuff.They drank anything between three and six drinks, however much was enough togive them a concentration of 0.11g of alcohol per 100ml of breath. This wouldput them two to five times over the drink drive limit, depending which countrythey were in. They then spent the night in the clinic and were woken at 7am forbreakfast before taking part in a battery of tests. For this they were paid arather generous $450. The researchers found the students who drank bourbonrated their hangovers as worse, but interestingly they performed just as wellon tasks such as reaction time tests.


Whisky contains high levels of 'congeners', which can makehangovers worse than paler drinks (Thinkstock)


Clear drinks such as white rum, vodka and gin tend to causefewer and less severe hangovers because they contain relatively low levels ofcongeners. Perhaps those who mix their drinks are more likely to choose adark-coloured drink containing higher levels of these substances simply byvirtue of their wider drinking range, but again it isn't the mixing in itselfthat causes the problem.


No scientist seems to have done the perfectcounter-balanced study where people are randomly assigned to drink beerfollowed by wine or wine followed by beer. But perhaps it's not the grape orthe grain that matters, but the effect that the strength of those drinks has onjudgement. Beer is only between a third and half the strength of wine, sostarting on it leads to less intoxication if followed by the stronger stuff.But if a person starts on wine or spirits, then their judgement may be impairedenough to drink more heavily later. There's certainly evidence that people arenot good at judging their own drunkenness. At low levels people overestimatethe amount of alcohol in our blood, but after a few drinks they start tounderestimate it.


So, the existing evidence suggests that hangovers can't beblamed on mixing drinks. It's probably down to the high congener count of thebooze, or over-drinking. As for hangover cures, scientists have looked intothose too, and the British Medical Journal published a review of trials ofeverything from borage to artichoke and glucose to prickly pears in 2005. Thebad news for drinkers is that none of them work.