Alcoholic drinks mixed with artificial sweeteners get you drunker, new research finds.

It took a group of Australian researchers, lots of orange-flavored vodka and a few tipsy volunteers to reach this scientific conclusion.

They found that artificial sweeteners found in such popular mixers as Diet Coke and sugar-free Red Bull lead to a high rate of alcohol absorption, resulting in a greater blood alcohol peak and concentration than from drinks made with sugar-based mixers.

The reason, Australian investigators told attendees at Digestive Disease Week 2006, is the accelerated emptying of the stomach caused by artificial sweetening agents.

Dr. Chris Rayner and colleagues at Royal Adelaide Hospital studied eight healthy male volunteers. On one day, the subjects consumed an orange-flavored vodka drink made from alcohol and a mixer sweetened with sugar containing 478 calories. On the second day, the men drank the same amount of alcohol with a diet mixer containing 225 calories.

The researchers measured the rate of stomach emptying using ultrasound technology. Blood samples were also taken at 30-minute intervals for three hours.

The stomach had emptied half of its contents in 15.3 minutes after the diet drink and 21.1 minutes with the sugar-sweetened drink.

The peak blood alcohol concentration was significantly higher with the diet drink than with the regular drink. The blood alcohol concentration was also higher with the artificial sweetener than with the sugar-sweetened drink.

It was surprising how much of a difference the artificial sweetener made, Rayner said.

People tend to consume more because of the lower calorie content, he stated. These drinks also tend to be consumed at times other than meal times, when food would slow gastric emptying.

The findings have public health significance, Rayner said. He recommends that product labeling include information on the intoxicating qualities of artificially sweetened alcoholic drinks. There could be legal implications for those driving home, as well, he noted.