For decades, scientists have been studying how alcohol affects our bodies. Some studies have suggested modest amounts, such as a glass or two of red wine per day, are associated with decreased inflammation, improved blood pressure and a lower risk of death from coronary artery disease.
Research has also linked it to an increased risk of various cancers and reduced brain volume over time.
So which is it — is moderate drinking good or bad?
A team of researchers recently analyzed the connection between genes linked to alcohol consumption and cardiovascular conditions and found that drinking — any amount — was associated with an increased risk of disease.
The study, which was published last week in JAMA Network Open, examined genetic and medical data of nearly 400,000 people through the U.K. Biobank, a large research database in Britain containing genetic, lifestyle and health information available for public health research. The findings showed that even low alcohol intake was associated with a small increased risk of cardiovascular issues, such as hypertension and coronary artery disease, but that risk ramped up exponentially with heavier consumption.
It also suggested that the previously held theory that modest drinking, namely of red wine, may help decrease the risk of heart disease is probably not the case. Individuals more likely to drink low to moderate amounts of alcohol also appeared to be more health-minded than those who abstained from it — for example, smoking less, exercising more and eating healthier — all factors that contribute to better heart health, said Krishna Aragam, senior author of the study and a cardiologist at Massachusetts General Hospital.
He said these other factors, such as diet and exercise, may be “mediating that reduction risk” of cardiovascular issues attributed to low amounts of alcohol consumption. “Maybe it’s not the alcohol itself,” he said.
Even red wine, which has been touted at times as being heart-healthy, does not seem to have substantial benefits.
Some research has suggested resveratrol, a compound found in grape skins, particularly those of red grapes, may act like antioxidants and contribute to heart health, but most likely not enough to have a meaningful impact. Another study found that a person would have to drink at least 500 liters of red wine per day to get enough resveratrol to benefit from it.
Given the recent findings on alcohol consumption and cardiovascular disease risks, Stanley Hazen, a cardiologist at Cleveland Clinic who was not involved in the recent study, said he will be amending his recommendations to patients.
Hazen said when his patients have asked him about drinking in the past, he has told them it is fine in moderation and may even provide an advantage. “But now I think that was wrong,” he said, pointing to emerging research. “So for people who are at high risk of cardiovascular disease, which is over half the people who I see on a daily basis in my clinic, I am going to be recommending cutting back on alcohol.”
But cardiovascular health is not the only concern. Studies have linked moderate alcohol consumption to numerous types of cancers involving the mouth and throat, voice box (or larynx), esophagus, colon and rectum.
For women, light to moderate drinking has been associated with a significant increased risk of breast cancer.
Ernest Hawk, division head for cancer prevention and population sciences at the University of Texas MD Anderson Cancer Center, said there is not one particular way in which alcohol leads to cancer. “There are many different ways alcohol causes toxicity to cells that are believed to result in cancer development over time,” he said.
However, as with other health issues, alcohol’s role in cancer can be hard to assess because other factors, such as diet and exercise — or lack thereof — can influence cancer risk, too. Hawk said people who are heavier drinkers are also less likely to practice healthy lifestyles, so “it becomes difficult to dissect out alcohol’s contribution.”
Of course, it is less surprising that excessive or long-term alcohol consumption can cause problems.
For instance, such drinking can lead to significant damage to the liver. Initially, it can cause inflammation of the liver known as acute alcoholic hepatitis. But over time, it can lead to cirrhosis, which can cause liver cancer, liver failure and death, said Jamile’ Wakim-Fleming, director of the Fatty Liver Disease Program at Cleveland Clinic.
That’s why, health experts say, it is important for people to consider their health and personal history — genetics, age, sex — when deciding whether and how much to drink, as alcohol does not affect everyone the same way. Young people’s brains continue developing until their mid-20s. Older people often have underlying conditions and take medications. And women do not produce as much of an alcohol-metabolizing enzyme called alcohol dehydrogenase, meaning alcohol is more toxic for them, Wakim-Fleming said.
Some doctors encourage people to limit their drinking, while others discourage it altogether. But for those 21 and older who do decide to drink, health experts say to pay close attention to the amount and concentration. For instance, one alcoholic drink is equal to a 12-ounce bottle of beer, a 5-ounce glass of wine or a shot — 1.5 ounces — of 80-proof liquor, according to the U.S. Department of Agriculture’s most recent Dietary Guidelines for Americans. Federal health authorities recommend that men limit their consumption to two drinks per day and women to one drink per day — any more than that is considered excessive drinking.
“Know your body,” Wakim-Fleming said. “Decide for yourself what’s good for you and discuss it with your doctor.”
Given the research, Aragam, senior author of the recent study, said medical professionals should probably not be recommending that people drink to improve heart health but said that does not mean everyone needs to avoid it entirely.
“It’s really just about being informed — knowing that the amount of the dose really matters,” he said.