The science behind the hangover: causes, myths, and prevention strategies

During major celebrations such as New Year’s Eve, many people drink more alcohol than usual, often resulting in a hangover the next day. A hangover is a group of physical and mental symptoms that appear when blood alcohol levels return to zero after heavy drinking. The most effective way to avoid a hangover is to drink moderately or not at all, especially for those who should not consume alcohol, such as minors, pregnant women, drivers, or people with certain medical conditions. However, for healthy adults who have overindulged, scientific research offers several strategies to reduce the impact of alcohol on the body and ease the symptoms of a hangover.

The physiological causes of a hangover are complex. One main factor is dehydration. Alcohol acts as a diuretic, causing the kidneys to remove more fluid and electrolytes from the body than usual. This leads to dry mouth, intense thirst, and headaches the following day. Another factor is the production of toxic byproducts during alcohol metabolism. The liver breaks down ethanol into acetaldehyde, which is more toxic than ethanol itself and responsible for nausea and general discomfort. Drinks with higher levels of congeners—secondary compounds produced during fermentation such as methanol and tannins—tend to cause worse hangovers. Darker or less distilled beverages like whiskey (especially bourbon), cognac, tequila, and red wine contain more congeners than clear spirits like gin or vodka. Studies show that whiskey produces more frequent and severe hangovers than vodka when consumed in equal amounts.

Excessive alcohol intake also triggers inflammatory and immune responses in the body. Research has found increased levels of pro-inflammatory cytokines in the blood during a hangover, contributing to muscle pain, fatigue, and difficulty concentrating. Alcohol can also cause low blood sugar by disrupting normal metabolism, which may worsen feelings of weakness and shakiness. While small amounts of alcohol may help some people fall asleep faster, heavy drinking disrupts sleep quality and leads to greater fatigue and irritability the next day. Alcohol also irritates the stomach lining, sometimes causing acute gastritis with symptoms like nausea, vomiting, and heartburn.

To reduce the risk or severity of a hangover, experts recommend several steps before drinking begins. Eating beforehand is crucial; food slows down the absorption of alcohol in the digestive tract. A meal rich in complex carbohydrates (such as bread or pasta), healthy fats (like olive oil or avocado), protein (such as lean meat or cheese), and fiber helps delay intoxication and lessens the intensity of a hangover. Skipping dinner before drinking increases both intoxication speed and hangover severity.

Hydration is another key preventive measure. Drinking one or two glasses of water before consuming alcohol helps maintain baseline hydration levels. Some experts suggest including an electrolyte-rich beverage before drinking to help offset losses caused by alcohol’s diuretic effect, though evidence for this is mostly anecdotal.

Getting enough sleep before a night out can also help. Being well-rested does not prevent a hangover but can make it easier to cope with its effects by reducing accumulated fatigue.

A balanced diet with adequate vitamins and minerals may play a role in how the body processes alcohol. Some studies suggest that people who regularly consume foods high in zinc and vitamin B3 (niacin) report milder hangovers. These nutrients are involved in breaking down ethanol and acetaldehyde in the liver. While some research has tested high doses of vitamin B6 as a preventive measure—with mixed results—there is no consensus on using vitamin supplements specifically for hangover prevention.

Planning ahead for responsible consumption is important. Setting a limit on drinks before going out and arranging safe transportation home are essential steps for safety.

While drinking at an event or party, pacing oneself is critical. The liver can only process about one standard drink per hour; drinking faster than this leads to higher blood alcohol levels and worse hangovers later on. Alternating alcoholic drinks with water or other non-alcoholic beverages helps maintain hydration and reduces total alcohol intake.

It is best to avoid mixing alcohol with sugary sodas or energy drinks. Sugary mixers can mask the taste of alcohol, leading people to drink more quickly or in greater quantities. Excess sugar can also worsen dehydration and contribute to fatigue by causing swings in blood sugar levels. Some studies suggest that carbonated sugary drinks may speed up alcohol absorption compared to drinking spirits alone.

Choosing drinks with fewer congeners can also help reduce hangover severity. Clear spirits like vodka or gin generally produce milder hangovers than darker liquors such as whiskey or brandy when consumed in similar amounts. White wine tends to cause less severe symptoms than red wine; light beer usually causes fewer problems than dark beer or heavily fermented craft brews.

Finally, it is important not to rely on eating after drinking (“late-night meals”) as a way to prevent hangovers; by that time most alcohol has already been absorbed.

In summary, while there is no guaranteed cure for a hangover once it sets in, scientific evidence supports several practical measures: eat well before drinking; stay hydrated throughout the evening; pace your consumption; choose drinks wisely; avoid excessive sugar or caffeine; get enough rest beforehand; and plan responsibly for your safety and that of others around you. These steps will not eliminate all risk but can significantly reduce both immediate harm from intoxication and the unpleasant aftereffects that follow festive celebrations involving alcohol.