The case of a 26-year-old woman from Northern Ireland has been raising conversation about the harmful effects of drinking too much Red Bull after she was diagnosed with obesity-induced idiopathic intracranial hypertension (IIH), a condition that causes blindness in later stages.
Lena Lupari acquired a growing dependency on Red Bull over several years, spending just under $10,000 a year to support her 2 gallon-a-day habit.
"I used to drink 28 cans of Red Bull in a day and I'd only have a meal at night but it would usually be something fast-food like a takeaway or a packet of pasta. I've got three young children, one with special needs, and didn't have time to make anything."
Lena first noticed problems when her migraines became more frequent, until she finally collapsed in June as a result of brain swelling.
"I'd been suffering from migraines and headaches for about five years but I just ignored them and took painkillers. Then my vision went and I couldn't even lift my head off the bed and I ended up in hospital for six days."
You might think this sounds like a case of overindulgence, but according to a study published in the journal Investigative Ophthalmology & Visual Science, research has found that drinking more than three cups of coffee a day (the caffeine equivalent of three cans of Red Bull) can increase the risk of vision loss and blindness, making developing glaucoma or other eye conditions much more likely.
The official Red Bull website recommends that people should not drink more than the equivalent of five cans a day.
As for Lena, she is currently following a physician-monitored diet with the goal to lose around 100 pounds and lessen the symptoms and progression of her condition. She has also successfully cut out Red Bull entirely.