Thank you for your question!
Both you and your daughter is correct. Drinking alcohol is better
known as ethanol, and it is indeed a primary alcohol. Primary alcohols
break down through oxidation into structures called aldehydes, rather
than the ketones that come from oxidation of secondary alcohols. The
aldehyde produced by ethanol, or drinking alcohol, is known as
ethanal. Ethanal does not have a displeasing odor, but rather an
So your daughter is correct about the chemistry of this question.
However, alcohol does contribute heavily to bad breath, due to its
mouth drying effects, according to several independent sources on
"Alcohol, alcohol-containing mouthwashes, heavy exercise and fasting
can all result in a dry mouth and worsen a bad breath problem."
"Alcohol causes horrible bad breath and lousy taste. Alcohol makes the
mouth extremely dry and will cause instant bad breath. It doesn't
matter if the alcohol is in wine, beer or even commercial mouthrinse.
In addition, several studies have shown that too much alcohol over a
period of time can destroy oral tissue."
"Alcohol is a very good drying agent, and therefore should be avoided
when ever possible. It drastically increases the numbers of anaerobic
bacteria and is a major cause of dry mouth. Apart from this fact
alcohol is known to cause pre cancerous changes to oral tissue. This
also includes the alcohol found in most commercial mouthrinse."
Google Search Strategy:
alcohol bad breath ketones
alcohol "bad breath"
alcohol primary secondary
smell OR odor aldehydes
smell OR odor ethanal
I hope this helps. If you need any clarifications, please don't
hesitate to ask. I would be more than happy to assist you further.
Clarification of Answer by
01 Nov 2002 18:21 PST
Thanks goes to Alexander-ga for the information in the comments below,
it appears to be right on point. He is correct. Acetic acid is another
name for the aldehyde ethanal, which is the oxidation of ethanol. I
maintain that the principle reason for the bad breath is due to the
diuretic properties of alcohol. However, according to the Berkeley
Smell Database, ethanal (acetic acid) may not be as pleasant an odor
at all. In fact, it can smell like vinegar.
I suspect that it is this combination of vinegar odors combined with
the mouth drying effect of ethanol that is responsible for the
If you have any more clarifications requests, please don't hesitate