With the statistical power of seven international research studies, this analysis confirms for the first time there was a continuous increase in blood pressure measures in both participants with low and high alcohol intake. Even low levels of alcohol consumption were associated with detectable increases in blood pressure levels that may lead to a higher risk of cardiovascular events.
"We found no beneficial effects in adults who drank a low level of alcohol compared to those who did not drink alcohol," said senior study author Marco Vinceti, M.D., Ph.D., a professor of epidemiology and public health in the Medical School of the University of Modena and Reggio Emilia University in Italy and an adjunct professor in the department of epidemiology at Boston University's School of Public Health. "We were somewhat surprised to see that consuming an already-low level of alcohol was also linked to higher blood pressure changes over time compared to no consumption -- although far less than the blood pressure increase seen in heavy drinkers."
"Our analysis was based on grams of alcohol consumed and not just on the number of drinks to avoid the bias that might arise from the different amount of alcohol contained in 'standard drinks' across countries and/or types of beverages," said study co-author Tommaso Filippini, M.D., Ph.D., an associate professor of epidemiology and public health in the Medical School of the University of Modena and Reggio Emilia in Italy, and affiliate researcher at the University of California Berkeley School of Public Health.
Researchers reviewed the health data for all participants across the seven studies for more than five years. They compared adults who drank alcohol regularly with non-drinkers and found:
Systolic (top number) blood pressure rose 1.25 millimeters of mercury (mm Hg) in people who consumed an average of 12 grams of alcohol per day, rising to 4.9 mm Hg in people consuming an average of 48 grams of alcohol per day. (In the U.S., 12 ounces of regular beer, 5 ounces of wine or a 1.5 ounce shot of distilled spirits contains about 14 grams of alcohol. Usual alcohol content differs in alcohol available in other countries.)
Diastolic (bottom number) blood pressure rose 1.14 mm Hg in people consuming an average of 12 grams of alcohol per day, rising to 3.1 mm Hg in people consuming an average of 48 grams of alcohol per day. These associations were seen in males but not in females. Diastolic blood pressure measures the force against artery walls between heartbeats and is not as strong a predictor of heart disease risk in comparison to systolic.
"Alcohol is certainly not the sole driver of increases in blood pressure; however, our findings confirm it contributes in a meaningful way. Limiting alcohol intake is advised, and avoiding it is even better," Vinceti said.