Alcohol and Metabolism: The Other Side of Booze

Human beings are opportunistic omnivores. We can consume a wide range of foods and drinks, while our genetics provides us with an enviable ability to use them as energy sources. The key to turn these foods and drinks into energy is our metabolism. 

But have you ever wondered how alcohol affects our metabolism? Read on to find out. 


To understand the effects of alcohol on metabolism, we first need to understand what metabolism is. For this, we'll have to revise through some basic biology. The mechanics in our body that keep us functioning are known as metabolism. This includes everything from the role that enzymes play in helping us grow, maintain ourselves, reproduce, and respond to our environment. Metabolism also converts the foods and drinks we consume into usable substances for the body, aiding our digestion. 

Although all human beings share the same basic metabolism, our specific genetic makeup determines our individual metabolism's precise working. How we respond to different substances is affected by variations in specific enzymes. This is especially true in the case of alcohol. 

Alcohol and Metabolism

There are two specific enzymes known as alcohol hydrogenase (ADH) and aldehyde hydrogenase (ALDH), which are primarily used to break down alcohol. Although the liver plays a crucial role in helping the body deal with alcohol, the stomach, pancreas, and even the brain is also involved. 

When you consume alcohol, the first thing that happens is that the ADH turns it into acetaldehyde, a highly toxic substance that is a known carcinogen. This substance can potentially cause cancer. To save you from this possibly deadly side effect, the ALDH comes into play soon after this first stage. It quickly turns the acetaldehyde into acetate, which can be broken down into carbon dioxide and water. This makes it easier for your body to eliminate it. 

You may think that this makes it okay to drink as much alcohol as you want – but there's a catch. No matter how much alcohol you drink, your body can only process a limited amount each hour. You've probably heard people talk about 'one unit per hour'. The idea is that our liver can process about 10ml of pure alcohol every hour after it's been consumed. The issue is that this is a very vague rule of thumb and does not apply to everyone. 

Blurry People at a Bar

According to the National Institute on Alcohol Abuse and Alcoholism, if a fasting adult male rapidly consumes one to four standard drinks, it can take him between two to seven hours to return to a zero blood-alcohol content (BAC). Men who consumed only one drink took two hours to return to a BAC of 0.00. In comparison, it took those who consumed four drinks within an hour more than seven hours to return to a BAC of 0.00. 

However, it is essential to note that these numbers are average and do not apply to everyone. The way ADH and ALDH function can vary drastically from one person to another. Many factors, including our genetic makeup, determines how fast or slow these enzymes work. Those who are particularly prone to adverse effects of alcohol such as nausea, rapid heart rate, and facial flushes are likely to have fast working ADH and slow working ALDH, which causes the acetaldehyde to build up quickly without being eliminated on time. 

However, if the ALDH also works fast, the toxic effects of consuming alcohol may not be felt by us at all. This can easily lead a person to be more dependent on alcohol. Some studies suggest that people who have a short working variant of ALDH are more likely to become alcoholics simply because it is easier for them to drink. 

Practically speaking, there is nothing we can do about how these particular enzymes work, as it is determined by the genes we were born with. However, by learning how our bodies work, we can make better choices, especially when it comes to alcohol, and learn how it affects our metabolism. 

Alcohol's Effect on Our Metabolism

Unlike fats and sugar, our bodies cannot store alcohol for later use. As soon as we drink it, the alcohol is quickly absorbed through our small intestines and ends up in our bloodstream. Afterwards, it is directly sent to our liver to be dealt with. 

To put it simply, drinking alcohol causes every other digestive system in the body to be put on hold. This can lead to a build-up of fat in the liver, one of the most common causes of liver disease. 

Women Drinking Alcohol

The effects of alcohol on our metabolism are still not entirely understood, as they can be very complicated. Considering that alcohol is the most energy-dense substance after fat, you'd assume that drinking too much would cause you to gain a lot of weight. Beer belly, anyone? 

However, there are limited studies that show a direct relationship between alcohol and weight when looking at the whole population. Since the body prioritizes dealing with alcohol and heavy drinking can cause intestinal damage, consuming too much alcohol is associated with lower body weight than the opposite. This isn't a good thing at all since dependency on alcohol poses a high risk of malnutrition. 

Although our metabolism plays a part in how our body maintains itself, a significantly higher or lower metabolic rate doesn't necessarily predispose any of us to be prone to weight loss or weight gain. Since heavier people need more energy to keep going, they may have a higher basal metabolic rate than people who weigh less. 

However, if you're gaining weight due to alcohol, you have to be honest with yourself and admit that it is not likely due to your metabolism. An evening on the couch with a bottle of wine or a night out chugging beer with your buddies isn't precisely an evening at the gym, is it? 

Ultimately, you have a choice in how you treat the body nature has given to you. And the truth is that, even if it doesn't directly cause you to gain weight, alcohol doesn't do anything good for your body. It's quite the contrary. 

Drinking a glass of wine at the party or a beer with your friends may not be that bad for you, but getting drunk every time you want to take a break will cause some serious long term side effects. 

So treat your body well, and keep your alcohol consumption at the very minimum. Better yet, give it up entirely if you can.

Say No to Alcohol