Learn / A Sobering Look at Alcohol’s Effects on the Body
Alcohol is widely consumed and socially accepted by cultures around the world, and relaxed views on its use mean we often downplay its consequences. But beneath the casual enjoyment lies a hidden cost. Alcohol has a profound impact on the human body, affecting everything from our brains and nervous systems to our immune function and digestive health. Understanding the reality of how alcohol affects us empowers us to make informed choices about our consumption. By shedding light on its short- and long-term consequences, we can be more intentional about our relationship with alcohol and make choices that support us in living our best lives.
Alcohol has immediate effects on all of our bodily systems.
The intoxication you feel from drinking is due to alcohol’s effects on your central nervous system1 (CNS). Alcohol is a depressant, meaning it slows down the CNS. This system controls vital functions like thinking, movement, speech, coordination, and reaction time. As blood alcohol concentration (BAC) levels rise, the CNS becomes increasingly impaired. This is what causes the slurred speech, stumbling, difficulty thinking clearly, and impaired judgment we all know to be associated with drinking. These effects can significantly increase the risk of injuries,2 accidents, and harmful behavior.
Alcohol causes cardiovascular chaos. Initially, it increases your heart rate, putting extra strain on the heart muscle. This can be especially risky for people with preexisting heart conditions. Alcohol also decreases heart rate variability3 (which measures the regularity of your heartbeat), an indicator of overall health. And it relaxes blood vessels, which causes your blood pressure to temporarily increase. While this might feel relaxing in the moment, chronically elevated blood pressure can damage blood vessels, increasing the risk of heart disease and stroke over time.
Alcohol is highly aggravating to your digestive system. As it enters the stomach, it irritates the lining, causing inflammation and discomfort. This irritation can lead to nausea and vomiting, especially if you drink on an empty stomach. Alcohol disrupts your body’s natural digestive processes by slowing down the movement of food through the digestive tract and leading to bloating, indigestion, and heartburn. It also affects your ability to absorb nutrients.4
Even one night of heavy drinking can weaken your body’s natural defense system. Alcohol disrupts your production of white blood cells, which is how your body fights off infections. This temporary suppression of the immune system5 makes you more susceptible to catching illnesses, from the common cold to more serious infections. The good news is that the immune system rebounds relatively quickly once alcohol is eliminated from the body. Frequent heavy drinking, however, can have long-term consequences for your immune system function.
Alcohol can also influence long-term health outcomes.
Chronic alcohol use can have a devastating impact on mental health. Heavy drinking disrupts the brain’s delicate neurochemistry, leading to an increased risk for mood disorders like depression and anxiety. Alcohol also interferes with sleep quality, making symptoms of mental health conditions worse. Over time, excessive alcohol consumption damages brain cells6 and impairs cognitive function, leading to problems with memory, learning, and concentration. In severe cases, chronic alcoholism can increase the risk of dementia7 and other neurodegenerative diseases. Heavy drinking creates a vicious cycle where people struggling with mental health disorders use alcohol to cope with their symptoms, only to worsen them in the long run.
The cardiovascular system is also seriously impacted by the long-term effects of alcohol.8 Chronic heavy drinking can lead to high blood pressure (hypertension), putting a constant strain on the heart. Over time, this can damage the heart muscle, weakening its ability to pump blood effectively. These changes significantly increase the risk of heart attack, stroke, and other cardiovascular complications. Alcohol also damages blood vessels, making them more prone to narrowing and hardening, restricting blood flow and increasing the risk of heart disease.9
The digestive system suffers significant consequences from alcohol abuse.10 Long-term irritation from alcohol can lead to gastritis: a chronic inflammation of the stomach lining. Alcohol also impacts the pancreas, an organ that produces digestive enzymes. This can cause pancreatitis, a painful condition with severe complications. Perhaps most concerning is the increased risk of certain gastrointestinal cancers, including cancers of the esophagus, stomach, colon, and liver. Heavy alcohol consumption damages these tissues over time, creating an environment conducive to developing cancer.11
The body’s defense system takes a beating with chronic alcohol use. Heavy drinking weakens your immune system’s ability to produce and deploy white blood cells, leaving the body more vulnerable to illness. This chronic immune system suppression can lead to more frequent and severe infections, including pneumonia and tuberculosis. Alcohol also interferes with the body’s inflammatory response, hindering its ability to heal and fight off infections. These long-term deficiencies leave people with chronic alcohol problems more susceptible to a range of diseases.
Here’s how alcohol affects your brain, heart, liver, and digestive tract:
The brain bears the brunt of alcohol’s toxic effects. Chronic drinking disrupts brain chemistry, leading to imbalances in neurotransmitters—chemical messengers that are essential for communication between brain cells. In fact, research shows that even moderate drinking can affect how the brain is organized.12 This impairs cognitive function, affecting memory, learning, and concentration. Over time, heavy drinking shrinks brain tissue13 and damages brain cells, leading to problems with judgment, decision-making, and coordination. In severe cases, these changes can manifest as dementia or cognitive decline. Alcohol’s neurotoxic effects are especially harmful to the developing brain,14 meaning teens and young adults are at higher risk.
It’s often said that moderate alcohol consumption, especially red wine, is good for your heart. However, there’s not much evidence to support the protective effects of alcohol.15 And, the threshold for moderate drinking16 is far lower than most people think (one drink per day for women; 2 for men).
Conversely, excessive alcohol intake has a clear negative impact on heart health. It raises blood pressure, weakens the heart muscle, and disrupts heart rhythm—all significant risk factors for heart disease, stroke, and heart failure. The negative effects of alcohol on the heart far outweigh any potential benefits. If your goal is cardiovascular health, it’s best to make other healthy habits a part of your lifestyle.
The liver is the body’s workhorse for processing alcohol. When functioning at normal capacity, it breaks down alcohol into harmless byproducts. But excessive consumption overwhelms this function. As the liver strains to metabolize alcohol, fat accumulates in liver cells, which can eventually lead to fatty liver disease.17 If heavy drinking continues, this can progress to alcoholic hepatitis, an inflammatory condition that damages liver tissue. The most severe consequence is cirrhosis, where scar tissue permanently replaces healthy liver cells, significantly compromising liver function. This can lead to life-threatening complications like liver failure and internal bleeding.
In the digestive system, alcohol is a double-edged sword. It irritates the stomach lining, increasing the risk of gastritis and eventually causing ulcers. It can damage the lining of the small intestine, compromising your ability to absorb essential nutrients from food. This is why so many people who use substances long-term have vitamin and mineral deficiencies. Chronic alcohol abuse unbalances the gut microbiome,18 the community of bacteria essential for gut health and digestion. This not only causes digestive issues, but can affect mental health, due to the link between gut health and mood disorders.19
The pancreas aids digestion by producing enzymes that break down food. But heavy drinking seriously compromises this essential organ. Alcohol disrupts the pancreas’ normal function, triggering the enzymes to activate prematurely within the pancreas itself. This can eventually lead to alcoholic pancreatitis, a painful inflammation of the pancreas with severe complications. Repeated episodes of alcoholic pancreatitis20 can damage the pancreas permanently, reducing its ability to produce digestive enzymes and insulin—a hormone that regulates blood sugar. In severe cases, chronic pancreatitis can cause diabetes21 and malnutrition. Even moderate alcohol intake can increase the risk of pancreatitis in people with certain predispositions.
Alcohol increases the risk of several types of cancer.22 These include cancers of the head and neck, such as the mouth, throat, and esophagus. Acetaldehyde (a byproduct of metabolizing alcohol)23 and the alcohol itself damage these tissues, which increases the risk of developing cancer cells. Alcohol can also contribute to the development of breast cancer in women, and colon cancer in both men and women. And yes, even moderate alcohol consumption can elevate cancer risk. According to Breastcancer.org,
Compared to women who don’t drink at all, women who have three alcoholic drinks per week have a 15% higher risk of breast cancer.24 Experts estimate that the risk of breast cancer goes up another 10% for each additional drink women regularly have each day.
The best way to reduce this risk is to abstain from alcohol.
The link between alcohol and cancer25 is complex, but can be explained by a few processes at play:
All of this might sound scary—and these are serious risks that warrant concern. The good news is that decreasing your alcohol consumption dramatically reduces your cancer risk.28
Drinking has different outcomes for different people, for a few reasons:
Our genetic makeup plays a surprising role in how alcohol affects us. Certain genes influence how our bodies metabolize alcohol. Some people, for example, break down alcohol more slowly because of certain genetic variations.29 This means that consuming the same amount of alcohol as another person would cause them to have higher blood alcohol concentration (BAC) levels, which increases both intoxication and its associated risks.
Genetics can also influence how vulnerable you are to alcohol dependence.30 Variations in genes related to the brain’s reward system may make some people more sensitive to the pleasurable effects of alcohol, and more likely to develop an addiction.
How we drink significantly impacts how alcohol affects our bodies. Regular, moderate alcohol use31 (one drink per day for women, two for men) generally has less severe consequences compared to less frequent heavy drinking or bingeing.
Binge drinking,32 defined as consuming a large amount of alcohol in a short period, gets you drunk much more quickly and carries a higher risk of accidents, injuries, and alcohol poisoning. This drinking style easily overwhelms the body’s ability to process alcohol and leads to higher BAC levels and more strain on vital organs.
Chronic heavy drinking, regardless of the pattern, poses the most serious health risks, including long-term damage to the brain, liver, heart, and other organs.
Both age and gender influence how alcohol affects the body. Younger people tend to have less muscle mass and body water, leading to a higher blood alcohol concentration (BAC) for the same amount of alcohol consumed33 compared to older adults. Women tend to metabolize alcohol more slowly because, on average, they have less muscle mass and a higher body fat percentage than men. This means women typically reach higher BAC levels than men after consuming the same amount of alcohol.
If you choose to drink, there are some steps you can take to reduce its risks.
For people who choose to drink alcohol, the safest approach is moderation. For healthy adults, this means one drink per day for women and two for men. But it’s important to remember that even moderate drinking carries some health risks.34
For some people, complete abstinence is the healthiest choice. This might be the case for those with a family history of alcoholism or other vulnerabilities to addiction, or people with preexisting health conditions. Ultimately, the decision to drink is a personal one. By understanding the risks and benefits, you can make informed choices that support your long-term physical and mental health.
See our article on harm reduction for an in-depth look at reducing the negative consequences of substance use.
While moderation is key, even occasional drinking can take a toll. Here are some strategies to minimize its negative effects:
These practices can’t erase the risks of alcohol, but they can help your body cope and minimize the damage.
If you’re concerned about your drinking, getting a professional’s perspective is a great place to start. Addiction treatment specialists can perform an initial evaluation to determine the severity of your use, assess your need for treatment, and point you in the right direction.
Search our list of alcohol rehabs and reach out to a center today to get your questions answered.
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Tramacere, I., et al. “A Meta-Analysis on Alcohol Drinking and Gastric Cancer Risk.” Annals of Oncology, vol. 23, no. 1, Jan. 2012, pp. 28–36. ScienceDirect, https://doi.org/10.1093/annonc/mdr135.
Volkow, Nora D., et al. “Moderate Doses of Alcohol Disrupt the Functional Organization of the Human Brain.” Psychiatry Research: Neuroimaging, vol. 162, no. 3, Apr. 2008, pp. 205–13. ScienceDirect, https://doi.org/10.1016/j.pscychresns.2007.04.010.
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Spies, Claudia D. MD*; Sander, Michael MD*; Stangl, Karl PhD†; Fernandez-Sola, Joaquim PhD‡; Preedy, Victor R. PhD§; Rubin, Emanuel MD¶; Andreasson, Sven MD**; Hanna, Eleanor Z. PhD††; Kox, Wolfgang J. PhD*. Effects of alcohol on the heart. Current Opinion in Critical Care 7(5):p 337-343, October 2001.
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