Energy Drinks Raise Blood Pressure, Study Suggests

Energy drinks can raise your blood pressure, a new small study found.

The new research, published in the journal JAMA, found that drinking one 16-ounce energy drink raised blood pressure and a stress hormone among young adults.

In the study, the researchers had 25 healthy men and women drink a 16-ounce Rockstar energy drink on one day, and a placebo drink on another day. The researchers then measured the men and women’s blood pressure and their levels of the stress hormone norepinephrine before the trial and 30 minutes after they drank the beverage. They found that blood pressure levels went up and norepinephrine levels rose twice as much after people drank the energy drink compared to when they drank the placebo beverage.

Specifically, they found that mean blood pressure increased 6.4% after drinking the energy drink compared to the 1.0% increase seen with the placebo. Norepinephrine levels increased 73.6% after drinking the energy drink compared to 30.9% after drinking the placebo beverage.

The study size is very small with only 25 people, so more research is needed to look at the connection. However, the research is not the first to link energy drinks to heart-related issues.

In a statement sent to TIME, the American Beverage Association responded to the study saying, “The safety of energy drinks has been established by scientific research as well as regulatory agencies around the globe. Just this year the European Food Safety Authority (EFSA) confirmed the safety of energy drinks and their ingredients after an extensive review. Even so, America’s leading energy drink manufacturers voluntarily go far beyond all federal requirements when it comes to responsible labeling and marketing practices, including displaying total caffeine content – from all sources – on their packages along with advisory statements indicating that the product is not recommended for children, pregnant or nursing women and persons sensitive to caffeine.”

Read more: Energy drinks have doctors worried