Friday, January 17, 2014

You Can Tolerate More Alcohol if you are of a Certain Genetic Makeup and In Good Shape!

This blog is dedicated to my good friend Christine, who does not have a favorable experience with alcohol. She finds that when she just has one drink she becomes flushed, feels bad, and will become sick if she drinks more than two drinks within a few hours. I, on the other hand, (not that I have ever tried this), can consume a large quantity of alcohol in a short period of time and not experience any symptoms of being drunk. People are often amazed by this phenomenon, considering I am a small female who doesn’t drink a lot; so one would assume I cannot handle my alcohol.

WARNING: Super Sciency terms for the following paragraph:

Did you know that your genetics may play a huge role in how quickly you get drunk and how you metabolize alcohol? There is some truth to those college kids who say “I’m Irish so I can drink a lot!” Certain Asian populations, specifically East Asians such as the Han Chinese, Taiwanese and Japanese, have polymorphisms of the alleles involved in the enzymes used to metabolize alcohol. For alcohol to be metabolized, it must be converted from ethanol (alcohol) to acetylaldehyde, then acetylaldehyde to acetic acid. Alcohol dehydrogenase(ADH)  is the enzyme used for ethanol -> acetylaldehyde and acetylaldehyde dehydrogenase (ALDH) is the enzyme used for the second step. About 50% of people with Asian ancestry experience a mutated ALDH enzyme, which leads to an accumulation of acetylaldehyde. This build up causes facial flushing, increased heart rate, and an increased skin temperature after alcohol is ingested.

In addition to the specific mutations common in Asians that limit their ability to consume alcohol, certain populations have higher rates of alcohol elimination, which allows for more alcohol to be consumed without experiencing immediate negative consequences. Certain countries in Europe, such as Ireland, England, Germany, and Russia drink more than other countries, and some experts believe that is due to their normal ALDH enzymes and higher rates of alcohol elimination and metabolism.
Besides ancestry, body water percentage tends to play a huge role in the ability to metabolize alcohol. Body fat has low water content, whereas lean muscle is mostly water. Women tend to have “lower” tolerances because they have, on average, more body fat than men. Older people tend to have lower tolerances because they have less water (due to decreased muscle mass).  So, you theoretically will have the highest tolerance if you are a young and very lean man who is well hydrated.


My recommendations:  No alcohol is good for you; in fact, it is toxic to the body. Alcohol is very calorie dense (7 cal/gram compared to 4 cal/gram for fat and carbs), and is an easy way to add hundreds of useless calories to your daily intake. However, this blog was meant to be more entertaining and informative....so, if you’re looking to increase your alcohol metabolism perhaps you should hit the gym and start eating healthy! ;-)

My conclusion about why I can drink more is because I am of Eastern European and Irish heritage, I am pretty lean, still relatively young, and am always well hydrated. 

References:
3.     Edenberg HJ, Jerome RE & Li M (1999) Polymorphism of the human alcohol dehydrogenase 4 (ADH4) promoter affects gene expression. Pharmacogenetics 9, 25–30.

4.     Proceedings of the Nutrition Society (2004), 63, 49–63

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