The Scientist: Gina Sam, MD, a specialist in Gastroenterology and assistant professor of medicine at Mt. Sinai Hospital

The Answer: Alcohol “allergy” technically doesn’t exist, but you may still be able to blame your hangover on genetics. If you notice that very little alcohol is making you sick, you could have a mutation in the group of enzymes, called alcohol dehydrogenase enzymes (ADH), that your body needs to break down booze.

Let’s say you drink half as much as your companions and find yourself more sick than others. That could mean you’re lacking the ability to metabolize alcohol. When we ingest alcohol, ADH should get break it down into various chemicals like aldehydes and ketones (AKA the sugar and flavor that make up our drink of choice). Some people are lacking this enzyme or their enzyme simply doesn’t work as well.

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Since this is a genetic issue, there isn’t much sufferers can do beyond monitoring their alcohol intake. (As one of the chosen ones, I have to remind myself to drink slowly and have a full meal after even one glass of wine.) Men tend to metabolize alcohol a little easier; people of Asian descent are prone to have less ADH. About 36% of East Asians (Japanese, Chinese, and Koreans) have a similar symptoms to drinking alcohol that includes facial flushing, nausea, and a faster-than-normal heartrate (called tachycardia).

There is one other potential culprit: Medication from antibiotics to antidepressants can affect your ADH in all kinds of ways. Meds may inhibit ADH or make it work even harder, so you could find yourself way more intoxicated than you’d hoped or nowhere near a buzz depending on your medication. (Another good reason to always check your drug interactions.)

Aside from struggling through a rough night, there isn’t much you can do to test for this ailment. Enzyme tests do exist, but they may not be covered by insurance and are only done by highly specialized labs. If you’ve gotten sick after two ounces of booze, chances are you’re “allergic” to alcohol. At least that’s a good excuse for skipping the next happy hour! 

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