[...] I've been wondering: are there any horrible side-effects from drinking more than 1 per 24 hours?Probably not, but maybe you should know that some energy drinks (like a lot of other soft drinks, too) contain
Sodium Benzoate, which is linked to ADHD.
WikipediaResearch published in 2007 for the UK's Food Standards Agency suggests that sodium benzoate (E211) is linked to hyperactive behaviour and decreased intelligence in children. According to the report, a high consumption of sodium benzoate is associated with a reduction in IQ of close to 5.5 points. [12] On 6 September 2007, the British Food Standards Agency issued revised advice on certain artificial food additives, including sodium benzoate (E211)