How alcohol affects your health

From DNA to hormones, heavy drinking can alter your body’s biology in a big way. Overdoing on alcohol can have a much bigger impact on your body than just one day of misery.

The cumulative effects of heavy drinking were revealed in a large-scale study of almost 600,000 drinkers in 19 countries. Researchers found that drinkers who downed between 14 and 25 drinks per week, approximately, had an average lifespan up to two years shorter than those who drank a maximum of around seven alcoholic drinks per week. The findings, which were published in April 2018 in The Lancet, also revealed that as weekly alcohol consumption increased, so did the risk of stroke, heart failure, and death from hypertension or aortic aneurysm.

The Centers for Disease Control and Prevention (CDC) defines heavy alcohol consumption as more than 8 drinks per week for women and 15 drinks for men. The CDC defines a drink as 12 ounces (oz) of any beer with an ABV (alcohol by volume) of 5 percent or less — an amount exceeded by many craft brews — 5 oz of wine, or 1.5 oz of distilled spirits such as vodka or rum. These serving sizes are often inflated by overpouring, so you may be drinking more than you realize. The CDC recommends moderate alcohol consumption, which is defined as two drinks per day for men and one drink per day for woman.

When it comes to excessive alcohol use, the main problem for most people is drinking excessively on a single occasion, known as binge drinking. That means four or more drinks for women, and five or more for men, in a two- to three-hour span.

“Having one drink every day of the week is not the same as having seven drinks on a Saturday,” says Kathy Jung, director of the division of metabolism and health effects at the National Institute of Alcohol Abuse and Alcoholism. “Binge drinking is never safe.”

In addition to taking years off your life, excess drinking can have other significant effects on your body and mind:

1.Changes your DNA and Makes you Crave More

Both binge drinking and heavy drinking can actually change your genetic makeup and leave you wanting more alcohol, more often, according to a study published in December 2018 in Alcoholism: Clinical & Experimental Research.

When researchers compared groups of binge drinkers and heavy drinkers to moderate drinkers (one drink per day for women and up to two for men), they found that an alcohol-induced gene modification process called methylation changed two genes in the bodies of the people in the former group. One of those genes, known as PER2, affects the body’s biological clock, and the other, POMC, regulates the stress response system. 

The result of these changes is an increased desire for alcohol. This finding provides evidence that excessive drinking can actually alter your genes and that these specific epigenetic changes in these specific genes is associated with an increase in the desire to drink alcohol. That may help explain why alcohol use disorder is so powerful and affects so many.

2. Increases the Risk of Certain Cancers

The National Cancer Institute (NCI) cites several studies, including one meta-analysis of 572 studies that showed that alcohol increases the risk of certain cancers, including those that affect the mouth, throat, liver, and breast. 

According to the NCI, they are five times more likely than nondrinkers to contract esophageal cancer. But even moderate drinking nearly doubles the odds of mouth and throat cancer. Having as little as one drink a day can increase the risk of breast cancer as well. Previous research published in the International Journal of Cancer found that alcohol contributed to approximately 5.5 percent of cancer occurrences and nearly 6 percent of cancer deaths worldwide.

3. Changes the Composition of Organisms in the Gut and Harms Immunity

Research focusing on the delicate balance of microorganisms that reside in the gastrointestinal tract has found that disruptions to these bacterial colonies can affect not only digestion but other aspects of health as well, particularly immunity. Consuming alcohol has been shown to affect this bacterial balance.

Studies have shown that alcoholics have a different balance of gut bacteria and impacts to their intestinal barrier, and chronic drinking has been shown to have harmful effects on immune system cells. Lowered immunity could explain why research published in October 2021 in World Psychiatry indicates that individuals with substance use disorders, including alcohol, have an increased risk of developing COVID-19, even after they have been vaccinated.

4. Affects Long-Term Memory and Brain Structure

One night of binge drinking can lead to blackouts that wipe out memories of key events and details, and consistent alcohol consumption can affect long-term brain function. 

People who drink heavily over a long period of time are at risk of changing the brain’s “hard-wiring,” which can lead to cognitive problems even after sobriety is attained, reports American Addiction Centers. Heavy alcohol consumption can also impact the brain long term and raise the risk of stroke and depression, and research conducted in May 2021 at the University of Oxford in the United Kingdom found that even moderate drinking decreases the brain’s gray and white matter. The findings concluded that there is “no safe level of alcohol consumption for brain health.”

5. Causes Hormonal Disturbances

Chronic heavy drinking can also wreak havoc on the endocrine system, which acts as one of the body’s main lines of communication between organs and other systems (like the nervous and immune systems). 

Similar to the way alcohol creates an imbalance in the gut, it also throws the endocrine system off-kilter by disrupting the release of important hormones, creating hormonal disturbances that can permeate every organ and tissue in the body, per a study published in 2017 in Alcohol Research: Current Reviews. The study reports that the disturbances can go as far as causing reproductive dysfunction, thyroid problems, immune system abnormalities, diabetes, cardiovascular disease, cancer, and psychological and behavioral disorders. There is also research that suggests alcohol increases production of the stress hormone cortisol during and after drinking, which consequently increases blood pressure and causes higher amounts of stress.