Just one caffeinated energy drink could increase the risk of heart attack and stroke in 90 minutes, a new study has found.
Energy drinks like Red Bull and Monster have been linked to stomach, nerve and heart problems in the past, but this study by the University of Texas is one of the first to shed light on the potential increased risk of heart attack and stroke.
Under 18s, women who are pregnant or breastfeeding, caffeine-sensitive individuals, those taking stimulants or caffeine-based drugs or those with heart disease should stay away from energy drinks, a lead researcher at the university in Houston said.
The drinks narrow blood vessels – which can restrict the flow of blood to vital organs.
“A lot of young kids use energy drinks when they exercise, a time when you need your arterial function to be at its top,” explained lead researcher Dr. John Higgins.
“It’s more work for the heart and less oxygen supply for the heart. This could explain why there have been cases where kids have had a cardiac arrest after an energy drink,” he said.
The Texas study included 44 healthy, non-smoking medical students in their 20s, who consumed a 24-ounce energy drink.
They were tested before and after they consumed the energy drink, and again 90 minutes later.
The researchers looked at artery flow-mediated dilation – an ultrasound measurement that is an indicator of overall blood vessel health.
Researchers found that after 90 minutes, the internal diameter of blood vessels tested was dramatically smaller, on average, than before.
This negative effect on blood vessels may be related to ingredients in the energy drink, such as caffeine, taurine, sugar and other herbals, the researchers suggested.
Taurine is an amino acid which is thought to increase energy. It was originally extracted from bull semen, which is where Red Bull gets its name, according to the research team.