After a night out of drinking, you might be searching for any remedy to relieve your hangover such as aspirin, hangover supplements, energy drinks, or coffee. However, while coffee has been traditionally seen as a hangover cure, a deeper look into the effects that coffee can have on your already abused body suggests that it offers quite the opposite of hangover relief.
Having said that, extensive research has shown that there are several beneficial effects of caffeine in the diet, such as improved attention, alertness, and physical performance. However, there can be adverse effects, such as dehydration and disturbed sleep patterns.
So does caffeine help hangovers or not?
Coffee Won’t Sober You Up
First of all, coffee won’t sober you up. Drinking espresso after alcohol will neither lower your blood alcohol level nor prevent you from staying drunk. Caffeine will help you with improved attention and physical performance, however, the effects of alcohol will still linger.
As a matter of fact, one study with rats found that caffeine – the equivalent of between one and eight cups of coffee for humans – made the rodents more alert but did nothing to reverse the cognitive impairment caused by alcohol, such as their inability to avoid stimuli they should have known were unpleasant [2, 3]. In other words, a shot of caffeine after a binge may simply fool drunk people into thinking they are sober.
Mild Dehydration From Coffee
Water makes up between 55-75% of the human body. It is needed to maintain the health and integrity of every cell in the body and is also necessary for most body functions. There are many ways we lose water on a daily basis, and that includes drinking alcohol and coffee.
Alcohol is a diuretic as well which makes our body dehydrated - therefore rehydration, in order to cure a hangover, is needed. Caffeine works as a diuretic through several mechanisms – it causes more frequent urination, prevents water depletion and causes the bladder to be incapable of holding larger amounts of urine.
Coffee, tea, soda, and energy drinks are all popular caffeinated beverages. All of these beverages also have mild diuretic effects on the body.
In other words, having a lot of coffee the morning after heavy drinking would make your body even more dehydrated and therefore your hangover worse. Therefore, if you absolutely can't go without a cup of coffee, you have to be sure to drink lots of water to avoid double dehydration from alcohol and coffee.
Caffeine May Avoid a Withdrawal Headache
If you’re a regular coffee drinker, you may have a mild caffeine addiction and need to drink coffee every morning. Should you skip your morning coffee, withdrawal symptoms may make your hangover worse. The headache you already have from drinking alcohol could become more severe if you don’t have at least a little caffeine.
The only way coffee helps a hangover is by preventing caffeine withdrawal from making it worse. In this situation, though, coffee’s not alleviating the hangover symptoms. It’s simply preventing other symptoms from developing that would compound the present ones.
Coffee Could Make Your Headache Worse
Coffee could also worsen your headache as caffeine slightly constricts blood vessels and raises the blood pressure. If you are already suffering from a pounding head, coffee might make the pounding even worse.
On the other side, a cup of coffee could make you feel a bit less sleepy and give you some energy – it is assumed that the energy boost lasts for only around three hours after a night out. As caffeine aids in elevating dopamine levels it could also make you feel a bit better in the morning, but cannot cure a hangover.
Bottom line, drinking coffee could make your headache worse. The caffeine that you might need to prevent a withdrawal headache would also intensify your hangover headache. Caffeine narrows blood vessels, which increases blood pressure. If your head is already pounding, this would make the pounding worse.
Additionally, as mentioned earlier, coffee is a diuretic, so it’s easy to become dehydrated. This further narrows your blood vessels, increasing your blood pressure even more.
Conflicting Views: Caffeine & Hangovers
While some studies claim that caffeine eases hangovers,6 two of the main symptoms of a hangover are nausea and shakiness, which are also two of the main side effects of excessive caffeine. Drinking coffee when you are hungover might have you feeling more awake, but will also worsen your stomach problems and dehydrate you even further.
All in all, there’s little evidence that coffee can cure hangovers or that it actually does anything to combat the effects of alcohol. In fact, there’s no evidence that it can relieve them. You may still want to have one morning cup of coffee after a night out. But more importantly, you will need to rehydrate after drinking alcohol with lots of water and supplement it with B vitamins and electrolytes.
After all, by drinking plenty of water and minimizing your coffee intake, you’ll keep your blood vessels dilated and blood pressure low.
Caffeine Doesn't Reverse the Negative Cognitive Impact of Alcohol
Effects of ethanol and caffeine on behavior in C57BL/6 mice in the plus-maze discriminative avoidance task