How harmful is it to drink a mix of beverages?

Question

I remember a long time ago (perhaps 20 years ago) that an elementary school textbook on health said "mixing alcohol beverages exacerbates the strength of the alcohol in the drink, thereby potentially being fatal to those who drink mixed beverages."

Is this actually true? To my knowledge, basic chemistry dictates that you cannot have more concentration of an element than there was before you mixed the two beverages; for instance, if you mix 100ml of beer(4.5%) and 10ml of spirits(20%), you will only have a 110ml of mixed beverage with 6.5ml of alcohol(4.5%*100+20%*10). In other words, you will have a 110ml(5.9%) drink. Which can't be that much more dangerous than drinking 100ml of beer(4.5%).

So maybe I am remembering the textbook wrongly -- maybe it said that mixing drinks leads you to drink more alcohol? Or is it true that there is a third effect going on -- maybe mixing two different drinks leads to a new, more stronger substance that is greater than the mix of the two drinks? Perhaps because different drinks have different kinds of ethanol mixed into them such that when you combine the two there is a sort of alchemy that makes two seemingly harmless drinks into a sip of poison?

I wonder...

Answer 1

The cumulative dose of ethanol is the actual issue, from the medical standpoint. However, if you start with beer or mixed drinks by the time they take effect someone has suggested drinking straight vodka and your ability to make decisions has been compromised such that you just go along with it even though sober you would not consider it. In the end, you are in my emergency department vomiting and barely responsive with an ethanol level of 400 mg/ dL.

Beer is a very weak alcoholic beverage relative to distilled spirits, but it takes very little alcohol in the system to impair judgment enough to move onto more dangerous solutions, hence the downward spiral of college fraternity parties.