Ask A Scientist: Why do you crave greasy food when you have a hangover?

By: Kylia Goodner

We’ve all been there: hungover and craving cold pizza the morning after a fun night out. But why do we crave pizza and greasy foods, instead of a large bowl of lightly seasoned quinoa and grapes? Biology has the answer in a little peptide called Galanin.

Galanin is a neuropeptide, which just means that it’s a very small protein that resides mainly in the nervous system, including the brain and spinal cord. Neuropeptides control many aspects of our day-to-day life. They tell us to move our hands when we’re touching a hot stove, and help us to remember our route to work. Although the main function of galanin is unknown, scientists have found exposure to fatty foods and ethanol causes more of it to be produced.

In laboratory rats, injection of galanin into a specific area of the brain, called the paraventricular nucleus, increased food intake in the hour after injection. Further, when scientists created mice without the ability to produce galanin, they found that they ate less fat and subsequently gained less weight than mice with galanin. So even without alcohol, if you eat fatty foods you’re going to produce galanin, which is then going to encourage you to eat fatty foods more often.

But what happens when you add alcohol? Unfortunately for us, the consumption of alcohol also increases the amount of galanin in our brains. Researchers have found that if they give ethanol to rats, through ethanol injections or by adding it to their water, the amount of galanin the rats produce increases compared to rats not receiving ethanol. Scientists further confirmed the relationship between galanin and alcohol by injecting mice with galanin and then observing how much ethanol they voluntarily drank after the injection. They found that after injection of galanin, the rats voluntarily drank more ethanol than the rats that did not receive an injection.

So, eating fatty foods and consuming alcohol both cause your body to produce more galanin, which in turn drives you to eat more fat and drink more alcohol. It’s a vicious cycle, which can lead to numerous cold-pizza hangover binges. Luckily, scientists may have identified a way out. Recent research has found that properties in the ginseng berry may act as an anti-hangover agent by getting rid of some of the harmful chemicals, called free radicals, which cause hangovers. So, next time you’re feeling the ill-effects of a night out, grab some ginseng berries instead of the cold pizza. You’ll thank yourself for decreasing your galanin production and escaping the vicious cycle it causes!