Within 90 minutes of drinking one energy drink, blood vessels in the body have narrowed – restricting blood flow and raising the risk of heart attacks and strokes.
Researchers at the University of Texas at Houston investigated what actually happens after people consume an energy drink such as Red Bull or Monster.
Previous research has suggested that the drinks – which contain high levels of sugar and caffeine as well as ingredients such as taurine – can have effects on heart rate and blood pressure.
The researchers measured the ‘artery flow-mediated dilation’ of 44 students after drinking a large can of energy drink, using ultrasound.
They found that within 90 minutes, the internal diameter of blood vessels had been reduced by half.
‘As energy drinks are becoming more and more popular, it is important to study the effects of these drinks on those who frequently drink them and better determine what, if any, is a safe consumption pattern,’ said Dr John Higgins, a professor of medicine at the McGovern School.
Previous research suggested that drinking the fizzy, sugary drinks can trigger potentially ‘life threatening’ changes in blood pressure and heartbeat, a study has found.
The drinks cause ‘profound changes’ in the body – different to changes caused by drinking the same amount of caffeine in other drinks.
Researchers from the USAF Medical Centre at Travis Air Force Base in California said last year that people with high blood pressure, or heart conditions, might want to avoid the drinks.