"There's only one hard and fast rule in running: sometimes you have to run one hard and fast."

Sunday, June 28, 2009

The Latest in Bad Biochemistry

There have been anecdotes, seemingly forever, about the fat-burning properties of vinegar. Recently, there was a study (I'm missing the citation, I can find it if anyone really cares) in Japan that showed that feeding acetic acid to mice did indeed cause them to lose fat reserves. The study is flawed and, even if it weren't, it might not be applicable to humans (the biochemistry is slightly different; for example, vitamin C is not a vitamin for mice). Here's what would happen if you tried to lose weight as fat by drinking vinegar:

You'd get sick. Drinking appreciable amounts of this will cause nausea and, if one drank smaller amounts for a longer time, one's teeth would decay.

Acetic acid is known to be an effector of only a few enzymes. It is immediately turned into acetyl-coenzyme A, which in large amounts, triggers mitochondria to make oxaloacetate from acetate (in a few steps).

If the body is running an energy deficit, through fasting or exercise, acetyl-CoA enters the tricarboxylic acid cycle (one step of which requires oxaloacetate) and gets converted into energy. This happens at the expense of burning other energy sources, so it actually decreases fat burning.

If the body has an energy glut, acetyl-CoA condenses with two more acetyl groups to form hydroxymethylglutaryl-CoA (HMG-CoA). This HMG-CoA can be converted into cholesterol, but this is tightly controlled and would be a minor route of getting rid of excess acetyl groups. Alternatively, HMG-CoA can be degraded into ketone bodies in the same way that fats are used for fuel. This would retard fat burning.

So, you can drink vinegar, but it won't make you skinnier, unless it spoils your appetite.


Anonymous said...

As I'm sure you also know, cytoplasmic acetyl-coA is also directly converted into malonyl-coA which in turn is used in fatty acid synthesis

Matthew Patten said...


And I was going to switch to vinegar as my sports drink for my next race.

My boys would like the vinegar/skinnier comment.

They always say "People go to Jupiter to get more stupider"

SteveQ said...

Anonymous (DCS, is that you?), you're right, of course, and it's interesting to me that the process involves directly adding carbon dioxide in the form of carbonic acid.

Beth said...

I am reminded of why I became an accountant and not a scientist. You lost me at acetylcoenzyme A. I'll assume the main point is not to drink vinegar. Good advice! :)

johnmaas said...

During my diet in the last few months, I would use vinegar as a dressing choice on salads because it has less calories. Didn't realize there was so much biochemistry involved.

Karen G said...

I am happy to know this. I tried the drinking vinegar but it was horrible, was thinking of ways to make it taste better.
And Matt obviously has boys not girls because everyone knows it is "Boys go to Jupiter...".