For years experts have touted moderate alcohol consumption as protective against heart disease. But a new study finds that just seven to 13 drinks a week can drive up blood pressure.
The study, which examined the health records of more than 17,000 U.S. adults, found that people who consumed moderate amounts of alcohol were more than twice as likely as nondrinkers to develop a more severe form of hypertension.
“If you are drinking moderately you should probably ask your physician or provider to check your blood pressure at each visit,” said the study’s lead author, Dr. Amer Aladin, a cardiovascular medicine fellow at Wake Forest Baptist Health. “If your drinking is moderate or heavy you should ask your provider to help you cut back.”
Aladin and his colleagues did not calculate risks for women and men separately. That is something the researchers plan to do in the future, he said. In general, women are already advised to consume less because they're more vulnerable to the effects of alcohol than than men.
To look at the impact of alcohol on blood pressure, the Wake Forest researchers turned to the Third National Health and Nutrition Examination Survey (NHANES III), a large decades long study led by the Centers for Disease Control and Prevention. The researchers analyzed data from 17,059 U.S. adults who signed on to NHANES between 1988 and 1994.
Participants were divided into five groups, which depended on the level of alcohol consumption: abstainers; former drinkers; those who consumed one to six drinks a week; those who consumed seven to 13 drinks a week; and heavy drinkers who consumed 14 or more drinks a week.
After accounting for factors such as age, sex, race, smoking status, physical activity BMI, cholesterol, and diabetes, the researchers found that compared to nondrinkers, moderate drinkers were 1.5 times more likely to develop stage 1 hypertension and twice as likely to develop stage 2 hypertension. Heavy drinkers were 2.5 times more likely to develop severe hypertension than nondrinkers.
Is there a safe level of alcohol?
Because the study was observational, it doesn't prove cause and effect. But it adds to the growing evidence that appears to contradict earlier research that found moderate consumption of alcohol could help protect against heart disease.
A 2018 study found that drinking more than five alcoholic beverages a week could raise the risk of stroke, heart disease and aneurysms and shave years off a person’s life. A global study published in August blamed drinking for 2.8 million deaths worldwide each year. Researchers who authored that study concluded that “the safest level of drinking is none.”
Stage 1 hypertension was defined as a systolic top blood pressure reading of 130 to 139 mmHg and a diastolic bottom reading of 80 to 90 mmHg. Stage 2 hypertension was defined as a systolic blood pressure of 140 mmHg or higher and a diastolic reading of 90 mmHg or more.
The associations were even more pronounced for heavy drinkers, who, for example were 2.5 times as likely as teetotalers to have developed stage 2 hypertension.
Hypertension is a clear risk factor for cardiovascular disease, said Dr. Omar Ali, director of the cardiac catheterization lab at the Detroit Medical Center’s Heart Hospital.
According to the Centers for Disease Control and Prevention, seven of every 10 people having their first heart attack have high blood pressure and about eight of every 10 people having their first stroke have high blood pressure.
The report will be presented on March 17 at the American College of Cardiology’s annual meeting.
CORRECTION: An earlier version of this story listed stage 1 hypertension as a systolic top blood pressure reading of 120 to 129 mmHg.