Does Eating Yeast Really Mitigate Alcohol Intoxication?

Jim Koch of the Boston Beer Company recently stated in an interview with Esquire Magazine that his secret to drinking without the intoxicating side effect was to eat  a teaspoon of baker’s yeast (mixed with yogurt). He claims that the enzyme alcohol dehydrogenase (ADH) in the yeast supplements our own ADH breaking down some of the alcohol reducing the amount that is absorbed by our bodies. Sounds too good to be true right? Well, I have a sinking suspicion that it is, so let’s take a look at the science.

Alcohol dehydrogenase in humans is an enzyme that catalyzes the reaction of alcohol to acetaldehyde that is found in the liver. It helps to clear alcohol from the body in a form that can be excreted. In contrast to humans, baker’s yeast have three types of ADH enzymes: ADH1, ADH2, ADH3 (similar to ADH1)¹. This is where things start to get a little fishy.

ADH1 in yeast actually reduces acetaldehyde and NADH to ethanol (making more alcohol) to regenerate NAD⁺, an important part of glycolysis (the cycle used to create energy from glucose)². As luck would have it, the most active form of ADH in baker’s yeast (the kind that Koch is eating) is ADH1¹. So essentially, as you’re breaking down ethanol in your body, yeast could be converting it back into ethanol canceling out what your body is doing increasing the effect of that beer.

The second form of alcohol dehydrogenase (ADH2), does in fact catalyze alcohol into acetaldehyde. The only issue is that ADH2 production is inhibited by the presence of glucose (sugar) in the environment³. So, Koch’s recommendation of mixing the yeast with yogurt would effectively repress the transcription of ADH2 reducing its activity.

If you’re still not convinced, the optimum range for these enzymes is in the neutral to alkaline range ¹. Your stomach, as I’m sure you know, is acidic (low pH), and would decrease the activity of the enzymes (if it didn't completely destroy them). Not to mention the fact that there are many beers produced that remain unfiltered, containing live yeast cultures in the beer, and do not lose the amount of alcohol in them as they age.

Sadly, it seems like the only way to "drink" without getting drunk is to stick with non-alcoholic beer (e.g. O'Doul's) or you could just drink responsibly, know your limits, and have a designated driver. If you have any other tips to mitigate the effects of alcohol while drinking let us know, and we will check them out to see if they are scientifically sound! Happy brewing.

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1. Leskovac, V., Trivic, S., Pericin, D. 2002. The three zinc-containing aclohol dehydrogenases from baker's yeast, Saccharomyces cerevisiae. FEMS Yeast Research 2:481-494
2.  Bennetzen, J.L., Hall, B.D. 1982. The primary structure of Saccharomyces cerevisiae gene for Alcohol Dehydrogenase I. The Journal of Biological Chemistry 257:3018-3025
3. Vallari, R.C., Cook, J.W., Audino, D.C., Morgan, M.J., Jensen, D.E., Laudano, A.P., Denis, C.L. 1992. Glucose repression of the yeast ADH2 gene occurs through multiple mechanisms, including control of the protein synthesis of its transcriptional activator, ADR1. Molecular and Cellular Biology 12: 1663-1673