Alcohol concentration and carbonation of drinks: the effect on blood alcohol levels

J Forensic Leg Med. 2007 Oct;14(7):398-405. doi: 10.1016/j.jflm.2006.12.010. Epub 2007 May 16.


Alcohol absorption and elimination vary considerably amongst individuals, and are subject to influences from a variety of factors. The effects of alcohol concentration and beverage mixer type on the rate of alcohol absorption, in a controlled environment was studied. 21 subjects (12 male, 9 female) consumed a solution containing alcohol, on three separate occasions. The three solutions were, A: Neat vodka (37.5 vol%), B: Vodka mixed with still water (18.75 vol%), C: Vodka mixed with carbonated water (18.75 vol%). The volume of alcohol each subject consumed was determined by Widmark's equation. The alcohol was drunk in a 5 min period following an overnight fast and breath alcohol concentrations were measured over a 4h period using a breathalyser. 20/21 subjects absorbed the dilute alcohol at a faster rate than the concentrated alcohol. The difference between the absorption rates was found to be significant (p<0.001). The use of a carbonated mixer had varying effects on the alcohol absorption rate. 14/21 subjects absorbed the alcohol with the carbonated mixer at a faster rate, with 7 subjects showing either no change or a decrease in rate. The mean absorption rate for solution C was 4.39+/-0.45 (mg/100ml/min), and the difference between this absorption rate and that with the still mixer (1.08+0.36) was significant (p=0.006).

MeSH terms

  • Adolescent
  • Adult
  • Breath Tests
  • Carbonated Beverages*
  • Central Nervous System Depressants / blood*
  • Central Nervous System Depressants / pharmacokinetics*
  • Ethanol / blood*
  • Ethanol / pharmacokinetics*
  • Female
  • Forensic Toxicology
  • Humans
  • Male
  • Sex Factors


  • Central Nervous System Depressants
  • Ethanol