Diet mixers make people drunk faster
Taking a drink with sugar-free versions of mixers, such as tonic water, cola, bitter lemon and lemonade, produces higher blood-alcohol levels.
The findings were revealed by Dr Chris Rayner, of the Royal Adelaide Hospital in Australia, at a conference in the United States. Dr Rayner, the lead author of the study, found that combining alcohol with a mixer containing artificial sweeteners resulted in significantly higher levels of blood-alcohol than the same drink taken with an ordinary mixer.
The blood-alcohol concentration peaked at 66 per cent higher, according to a study in which volunteers were given an orange-flavoured vodka drink made with either a diet or non-diet mixer.
An alcohol counselling organisation warned that people choosing to have a diet mixer should be aware of the effect.
Dr Rayner, appearing yesterday at Digestive Disease Week, a conference in Los Angeles, said: "More and more people are choosing diet drinks as a healthier alternative.
"What people do not understand is the potential side-effects that diet-mixed alcoholic drinks may have on their body's response to alcohol."
Researchers studied eight volunteers, tracking the rate at which the regular and diet alcoholic drink was emptied from the stomach and their subsequent blood-alcohol levels for three hours.
It took 21 minutes for half the diet drink to leave the stomach, compared with regular drinks, which took 36 minutes.
Peak blood-alcohol concentrations were found to be "substantially greater" with diet drinks at 0.05 per cent, while regular drinks measured at 0.03 per cent.
Alex Meikle, of the Glasgow Council on Alcohol, said his counsellors would be made aware of the study and the information would form part of its advice if the study was confirmed to be accurate.
"It is quite a significant finding and I will alert my counselling staff," he said.
"Obviously, you should be very careful how you mix your drinks. It is a message we have to give to female clients. A lot of women will go for Diet Coke or Diet Irn-Bru."
Dr Peter Rice, a senior Dundee University psychiatry lecturer specialising in alcohol misuse, said the key advice to people was to know their own limits.
However, Dr Rice added the main factor affecting absorption of alcohol was still likely to be the amount of food in the stomach.
Paul Waterson, of the Scottish Licensed Traders Association, said it was already known that fizzy drinks increased the rate of alcohol absorption. But he added: "The level of absorption isn't the problem - it's actually the alcohol that's the problem."