NHS medics issued an alert in the British Medical Journal after a fit man in his 50s who drank eight cans a day, unaware of the hidden dangers, suffered a life-changing stroke
Drinking too many energy drinks can leave otherwise healthy people at risk of a stroke, doctors have warned, as a man shared his terrifying experience after drinking eight cans a day.
Medics have issued the warning after publishing a case study on a fit man in his 50s who had a stroke after drinking eight cans a day. After medics encouraged him to kick the habit his blood pressure returned to normal, but he has been left with loss of feeling down his left side.
The man, speaking anonymously in the report published in the journal BMJ Case Reports, said: “I obviously wasn’t aware of the dangers drinking energy drinks were causing to myself. I have been left with numbness in my left hand side hand and fingers, foot and toes even after eight years.”
READ MORE: ’24 Hours in Police Custody gave me a headache – but then I nearly died’READ MORE: Brits urged to consider wearing face masks after horror superflu outbreak hits UK
The recommended maximum daily caffeine intake is 400mg. Tea contains around 30mg and coffee 90mg. Some larger energy drink cans can contain up to 500mg of caffeine in a single serving. However even this could be an underestimate.
The researchers who investigated the man who suffered a stroke point out that these drinks also contain high sugar content and other chemicals. They now suspect the interaction between all these is boosting the effects of the caffeine.
Author Dr Martha Coyle, of the stroke unit at Nottingham University Hospitals NHS Trust, said: “This declared amount is the ‘pure caffeine’, but other ingredients contain ‘hidden caffeine’ – for example, guarana is thought to contain caffeine at twice the concentration of a coffee bean. The hypothesis is that the interaction of these other ingredients, including taurine, guarana, ginseng and glucuronolactone, potentiates the effects of caffeine heightening stroke risk through numerous mechanisms.”
These include raising blood pressure. An MRI scan confirmed the man had suffered an ischaemic type of stroke, where small blood vessels become blocked. At the point of him being admitted to hospital, his blood pressure reading was very high at 254/150mmHg.
The NHS advises that normal blood pressure is between 90/60mmHg and 120/80mmHg. High blood pressure is considered to be 135/85 or higher if the reading was taken at home, or 140/90mmHg or higher if the reading was taken at a pharmacy, GP surgery or clinic.
The man was started on drugs in hospital to lower his blood pressure, which did work temporarily, but once back home, his blood pressure continued to rise and stayed high despite him being given extra drugs to control it. Medics questioned the man at one of his appointments and discovered he had been drinking an average of eight cans of energy drinks a day.
Each drink contained 160mg caffeine per 16 fluid ounces and this added up to a daily intake of 1200-1300mg of caffeine when the recommended maximum daily intake is 400mg, the doctors wrote. Once he stopped consuming the drinks, his blood pressure returned to normal and blood pressure lowering drugs were no longer needed.
Dr Coyle added: “It was therefore thought to be likely that the patient’s consumption of highly potent energy drinks was, at least in part, a contributive factor to his secondary hypertension (high blood pressure) and in turn his stroke. As our case and discussion illustrate, it is possible that both acute and chronic intake of energy drinks may increase cardiovascular disease and stroke risk.”
The doctors stressed that evidence overall is not conclusive as it is difficult to prove definitively that one factor caused the stroke. They have called for more research into the real impact of energy drinks. A spokesman for the industry-funded British Soft Drinks Association said: “The European Food Safety Authority confirms the safety of energy drinks ingredients and therefore does not provide any scientific justification to treat energy drinks differently than the main contributors to daily caffeine intake in all age groups, i.e. tea, coffee, chocolate and other non-alcoholic beverages.
“Food regulations dictate that drinks with an added caffeine content of more than 150 mg/litre must include the following: ‘High caffeine content. Not recommended for children or pregnant or breast-feeding women’ followed by a quantitative indication of the product’s caffeine content. This approach has been adopted universally across the EU and UK.”