How Our Amazing Body Processes Alcohol

Did you know that the average body, male or female, processes alcohol at the rate of one drink per hour? Whether you’re fat or thin, the processing speed stays the same. What does differ, though, is the blood alcohol level (BAC, or blood alcohol content) between the sexes.

Your biological sex plays a role in how quickly you process alcohol. Women tend to feel the effects more intensely, not just because they’re generally smaller in stature, but because they naturally have less water in their bodies than men. Water dilutes alcohol, so less water means a higher BAC. On top of that, women’s bodies produce less of the enzyme alcohol dehydrogenase (ADH), which is needed to break down alcohol in the stomach. That means more alcohol gets into their bloodstream before the liver even has a chance to metabolize it.

But sex isn’t the only factor. Genetics also plays a role. Some people are genetically wired to metabolize alcohol more efficiently due to variations in the ALDH2 and ADH1B genes. Ever met someone who gets red-faced after just one drink? That’s called alcohol flush reaction, and it’s due to a genetic deficiency in ALDH2. This leads to a toxic buildup of acetaldehyde (more on that in a bit), causing facial flushing, nausea, and an overall terrible drinking experience.

And then there’s body composition. Interestingly, people with more body fat tend to have higher BAC levels. Alcohol doesn’t dissolve well in fat, so it stays in the bloodstream longer, leading to stronger and longer-lasting effects. So, that was me: A short, fat, female, and an alcoholic.

Your Last Supper

Another major factor in how quickly alcohol is processed? What’s in your stomach. If you’ve got food in there, it slows alcohol absorption into the bloodstream. That’s why some serious drinkers skip meals—to avoid a “buzz kill.” But the kind of food you eat makes a difference, too. Protein and fatty foods delay alcohol absorption far more than carbs.

Even what you mix your alcohol with matters. Carbonation speeds up absorption, so drinking something fizzy—like champagne, beer, or a vodka soda—will make you feel the effects faster than, say, a vodka and orange juice. Why? Because the bubbles stimulate the stomach lining, making it easier for alcohol to pass through.

Here’s another wild fact: About 20% of the alcohol you drink gets into your bloodstream directly through your stomach. The remaining 80% is absorbed through the small intestine and makes its way into your system from there. That’s why drinking on an empty stomach hits so fast—there’s nothing slowing down the absorption process.

Our Liver: The Ultimate Workhorse

The liver is where the real magic (or mayhem) happens. It’s responsible for breaking down most of the alcohol you drink—but it can only handle so much at once. The liver uses enzymes to convert alcohol into acetaldehyde, a highly toxic and carcinogenic substance. Acetaldehyde is then broken down into acetic acid, which is further metabolized and eventually excreted as carbon dioxide and water.

Here’s where things get dangerous: If you drink too much too quickly, your liver can’t keep up. That means acetaldehyde builds up in your body, causing nausea, dizziness, headaches, and that terrible “hangover” feeling. Worse yet, chronic alcohol consumption damages the liver, leading to fatty liver disease, hepatitis, and cirrhosis—a condition where the liver becomes so scarred that it stops functioning properly.

For reference, in most U.S. states, 0.08 BAC is the legal limit for driving. But what does that actually mean? It’s measured as a percentage of alcohol in your bloodstream, so 0.08 means almost one percent of your blood volume is alcohol. It doesn’t take much to reach that level—just four drinks for women or five for men in about two hours can push you into that legally intoxicated range.

Not Just the Liver: How Alcohol Leaves the Body

The liver does most of the work, but alcohol actually leaves your body in multiple ways:

• Breath: 2-8% of alcohol is exhaled through your breath, which is why breathalyzers work.
• Urine: 5-10% is excreted through the kidneys.
• Sweat: 2-5% of alcohol leaves through your skin, which is why heavy drinkers often smell like booze even when they haven’t had a drink in hours.

But don’t fall for the “sweating it out” myth. No amount of exercise, saunas, or “detox” drinks will speed up alcohol elimination. Your liver still dictates the pace.

Everything Slows Down with Age

When you were younger, you could drink all night and still function the next day. But as we age, everything slows down—including our ability to process alcohol. The liver gets less efficient, the stomach produces less ADH, and overall body water decreases, meaning alcohol stays in the bloodstream longer.

Add in medications—which most people start taking as they get older—and you have a recipe for stronger alcohol effects even if you’re drinking the same amount you always did. This is why older adults tend to experience worse hangovers, faster intoxication, and increased health risks from alcohol consumption.

Breaking the Cycle

Drinking often starts as peer pressure fun in your teens, but before you know it, it’s a middle-age freak-out. You realize you’ve built a habit that you’re scared you can’t break. But the truth is, you can. It’s a habit. A bad one, yes—but still a habit. And habits can be broken.

That’s why I wrote Life’s Better Sober. It’s not just an eBook; it’s a 66-day roadmap to sobriety. But why 66 days? Research from University College London found that on average, it takes 66 days to form a new habit. It might take longer (or shorter) for you, but the key is consistency.

Will you stop drinking forever? No one can guarantee that. But you’ll never know how good sobriety can be unless you try. Nothing ventured, nothing gained. You know what? You might end up just like me—now 25+ years sober and loving it.

Sources:

1. National Institute on Alcohol Abuse and Alcoholism (NIAAA). “Alcohol Metabolism: An Update.” 2023. https://www.niaaa.nih.gov
2. Centers for Disease Control and Prevention (CDC). “Facts About Excessive Drinking.” 2023. https://www.cdc.gov/drink-less-be-your-best/facts-about-excessive-drinking/index.html
3. Harvard T.H. Chan School of Public Health. “How Alcohol Affects Your Body.” 2022. https://www.hsph.harvard.edu/nutritionsource/alcohol
4. University College London. “How long does it take to form a habit?” 2009. https://www.ucl.ac.uk/news/2009/aug/how-long-does-it-take-form-habit