These energy drinks contain around 80mg of caffeine per 250 ml of the drink. This is equivalent to around 2.5 cans of cola.
Why narrowed blood vessels are dangerous
Narrowed blood vessels restrict the flow of blood around the body.
According to the National Institutes of Health (NIH), if blood flows too slowly and it starts to build up, large numbers of blood platelets may group together and stick to each other, forming a blood clot.
“It is also not uncommon for them to form because the inner walls of blood vessels are damaged, for example in atherosclerosis,” explains the NIH.