People who do not drink alcohol and those who drink an average of seven drinks per week have similar levels of heart disease, according to a paper published last week in JAMA Network Open—but the risk increases rapidly as alcohol consumption rises, Gina Kolata reports for the New York Times.
Study details and key findings
For the study, researchers analyzed data from the U.K. Biobank to determine the relationship between alcohol consumption and cardiovascular diseases. From July 2019 to January 2022, they analyzed data collected from 2006 to 2010, with follow-ups through 2016.
Among the 371,463 individuals included in the study, the average age was 57, with a reported average of 9.2 alcoholic beverages consumed each week.
In their analysis, researchers found "an exponential curve of risk with the gene variants that suggest they drink more," Kolata writes. "The risks of heart disease and high blood pressure started slowly as the number of drinks increased, but they quickly gained steam, soaring as people got into the abusive drinking range of 21 or more drinks a week." However, they found that an individual's actual risk was dependent on whether they had other conditions, such as diabetes or obesity.
According to Krishna Aragam, a preventive cardiologist at Massachusetts General Hospital and an author of the study, the typical middle-aged person in the study who did not consume alcohol still faced an estimated 9% risk of developing coronary heart disease. While a similar person who consumed an average of one drink a day faced an estimated 10.5% risk.
Notably, the researchers used Mendelian randomization in their analysis while previous studies of alcohol consumption and heart health that were largely observational, following subjects over time to determine whether the amount of drinking was tied to heart health. While observational studies have been able to find correlation between heart health and alcohol consumption, the Biobank study was more suggestive of causality—which potentially gives its results more legitimacy, Kolata writes.
"We have to start thinking about those moderate ranges and inform patients accordingly," Aragam said.
"If you are choosing to drink, you should know that beyond a certain level, the risk ramps up quite a bit. And if you choose to drink less, you will get the bulk of your benefit if you go to the seven drinks a week range."
According to Amit Khera, an author of the study and a cardiologist at Verve Therapeutics, the "gold standard" to evaluate the impact of alcohol consumption on heart health would be a large randomized clinical trial. While a study like this was planned in 2017 by NIH, it was terminated because the researchers had inappropriate interactions with the alcohol industry while planning the study.
Still, Mendelian randomization techniques, like the ones used in the Biobank study, "are particularly helpful when a gold standard hasn't been, or can't be, done," Khera said.
Recently, Stanley Hazen, a cardiologist at the Cleveland Clinic, said two patients asked him how much daily alcohol consumption would be best for their heart health. He responded with widely accepted medical advice—and average of one drink each day helps the heart.
"I didn't give it a second thought," he said.
Soon after, he read the findings from the Biobank study, which he claimed, "totally changes [his] life." According to Hazen, the findings disrupted his thinking about what he should tell patients.
"Dose matters a lot," Aragam noted. "Just realize that, as you go up beyond modest ranges, the risk goes up quite a bit." (Kolata, New York Times, 3/29)