Is alcohol bad for your health? Here's what the science actually says

Last week, the Canadian Centre on Substance Use and Addiction (CCSA) released a 90-page report outlining new guidance on safe alcohol consumption. According to the CCSA, consuming more than two alcoholic drinks per week puts you at moderate risk of adverse health consequences associated with alcohol, like cancer, liver disease, and cardiovascular disease. In addition, the report suggests that three to six standard drinks a week puts you at risk of more than seven cancers. Those recommendations echo a statement from the World Health Organization earlier this year stating that “when it comes to alcohol consumption, there is no safe amount that does not affect health.”

In the United States, the dietary guidelines for alcohol intake are two drinks or less per day for men and one drink per day or less for women.

When you think about the harms associated with alcohol, the first images that might come to mind are car accidents, bar fights, and clumsy falls from high places. But according to a report published in JAMA in November of last year, only 40 percent of deaths attributed to alcohol among US adults aged 20 to 64 were “acute,” like a car crash or alcohol poisoning. The majority, the report alleges, were caused by chronic health conditions like liver disease, cancer, and heart disease.

But like so many health subjects, studies into alcohol’s effect on the body can yield murky and conflicting results. Is no alcohol always better than some alcohol? Can alcohol be beneficial in some ways while harmful in others? And how much alcohol can you safely consume without adverse health effects? Here’s what we know about alcohol and health outcomes.

Is wine good for your heart?

Some studies have suggested that wine has cardioprotective effects because of its polyphenols—a class of naturally occurring compounds found in fruits, chocolate, herbs, spices, and, yes, wine.

This is far from certain. While many studies have found an association between low to moderate red wine consumption and improved heart health, others have found the opposite. Further, the American Heart Association maintains that no research has found a direct cause-and-effect link between alcohol and better heart health. Rather, “studies have found an association between wine and such benefits as a lower risk of dying from heart disease.”

It may be that low to moderate wine drinkers have healthier habits than non-drinkers. They might follow a “Mediterranean diet,” which includes fish, nuts, whole grains, and other foods known to be healthy, in addition to wine. Further, other studies have found that people who abstain from alcohol are at no higher risk of heart disease than people who consume low to moderate amounts of alcohol, suggesting there may not be a cardioprotective effect. Further, at least one observational study published in JAMA last year found an association between habitual alcohol intake and an increased risk of cardiovascular disease. Last year, the World Heart Federation published a policy brief arguing that no amount or type of alcohol can be considered “heart healthy.”

Fortunately, polyphenols, which we know are good for human health, are not exclusively found in wine. They’re in many other plant-based foods, so if you want these antioxidant-like compounds' health benefits, you have options other than uncorking a bottle of Cabernet.

Does alcohol cause cancer?

Alcohol is a known carcinogen. When you drink alcohol, an enzyme in the mouth turns it into acetaldehyde, a chemical that damages DNA and prevents the body from repairing the damage. Noelle LoConte, a medical oncologist at the University of Wisconsin Carbone Cancer Center and associate professor of medicine at the University of Wisconsin School of Medicine and Public Health, tells Inverse that when you drink alcohol, “that carcinogen touches your mouth, throat, and esophagus as you swallow,” which is why researchers think there’s an association between those cancers and alcohol use.

“For breast cancer,” she adds, “alcohol increases the amount of estrogen in the blood. For liver cancer, alcohol causes cirrhosis which leads to cancer.”

A study published in Lancet Oncology in 2021 found that “globally, about 741,000, or 4.1 percent, of all new cancer cases in 2020 were attributable to alcohol consumption.” Three-quarters of alcohol-attributable cases were in males, and the cancer sites contributing the most attributable cases were oesophageal, liver, and breast (in females).”

The more you drink, LoConte says, the more your risk of developing alcohol-related cancer increases. The same is true for the length of time you are a drinker; if you’ve been a moderate drinker for 30 years, your risk of developing alcohol-related cancer is higher than someone who drank the same amount but for only ten years.

LoConte says you can bring these risks down if you quit drinking altogether, though it can take many years before your risk is that of lifelong teetotalers.

“We know from head and neck cancer research and esophageal cancer research that the risk decreases with time, but it takes about 20 years to come back to baseline. This is very similar to smoking and how long it takes for your risk to reduce to nonsmoking levels,” she says.

Does alcohol harm your liver?

In the United States, the most common individual cause of alcohol-related death is alcoholic liver disease, according to the Centers for Disease Control. The CDC estimates that between 2015 and 2019, about 22,400 people died from the condition annually.

Your risk of contracting alcoholic liver disease increases the more you drink and the older you get. Three stages characterize it:

1. Fat accumulates in the liver, resulting in “alcoholic fatty liver.”
2. Alcoholic hepatitis, which is inflammation of the liver
3. Cirrhosis, which occurs when the liver tissue becomes scarred

If you stop drinking, the first two stages are reversible; once the disease has progressed to the third stage, however, it is not reversible, even with alcohol cessation.

How to understand alcohol's risks to your health

Dan Malleck, a medical historian specializing in drug and alcohol regulation and policy and professor in the Department of Health Sciences at Brock University in Ontario, Canada, has a few qualms with the CCSA guidelines — which again state that more than two drinks per week puts you at risk for a number of diseases — and how we interpret alcohol research more broadly.

“It comes down to actual risk versus relative risk,” Malleck tells Inverse. “If your risk of dying from a disease is .0002 percent, or 2 in one million, and having three drinks a day raises your risk of dying from that disease by 100 percent, you now have a .0004 percent, or 4 in one million chance of dying from that disease.”

“I’ve heard a few people say, ‘you have a one in 100, or one percent, chance of dying from something because of drinking,’” Malleck says. “Which suggests you have a 99 percent chance of dying from something else. But it’s never framed that way.”

Are there any health benefits to alcohol?

While alcohol can unquestionably harm one’s health, Malleck thinks some potential health benefits are harder to quantify.

“It's important to recognize that, in general, one of the things people do when they go to a bar is not just to get in fights or to binge drink, but actually to see their friends, to hang out and commiserate or celebrate. Alcohol may be involved in that. Not necessarily, but might. But social connection and stress reduction are inherently beneficial to one’s health. So I don’t think we can dismiss that simply because alcohol may be involved.”

For her part, the University of Wisconsin’s LoConte and her colleagues intend their work to be informative; what other people choose to do with that information is up to them. “From a cancer prevention perspective, there is no ‘safe’ amount of alcohol,” she says. “If people choose to drink regularly for other reasons, that’s their choice. We want people to be informed. As it stands now, only 30 percent of Americans know about the alcohol-cancer link.”