A Sao Paulo university team plied 26 male volunteers* with booze, Red Bull or a mixture of both, and demonstrated what deranged clubbers already knew: mixing energy drinks with alcohol provokes "an increased sensation of pleasure and a reduction in sleepiness". Or, as team leader professor Maria Lucia Souza-Formigoni told the BBC: "The person is drunk but does not feel as drunk as he really is."

Souza-Formigoni explained: "In Brazil, as in other countries, people believe that Red Bull and other energy drinks avoid the sleepiness caused by alcoholic beverages and increase their capacity to dance all night." Her subjects fuelled with the Red Bull and alcohol mix did indeed report "less perception of headache, weakness, dry mouth and impairment of motor coordination".

And the danger? Thinking you're less legless than you really are and then taking the car for a spin. Souza-Formigoni's fellow researcher professor Roseli Boergnen de Lacerda, of the Federal University of Parana, duly warned: "The implications of these findings are that this association of alcohol and energy drinks is harmful rather than beneficial as believed by consumers."

A Red Bull spokeswoman declared: "Red Bull strongly advocates the responsible use of alcohol at all times. The position of Red Bull, in line with responsible adults and driving organisations worldwide, is that it is absolutely wrong to drink alcohol and drive at any time, regardless of whether alcohol has been mixed or not."

And the case for Red Bull? The spokeswoman added: "Driving organisations, including the RAC, have endorsed the sole consumption of Red Bull or other caffeine-based drinks whilst driving to improve concentration and reaction time, and therefore safety."