The results were pretty shocking: Norepinephrine levels — a stress hormone that controls your "fight or flight" response — had spiked almost 75% thirty minutes after people downed the drink. Blood pressure also rose by an average of 6.6 points.
Not only are those effects harmful in the short term, but the researchers note that these physical changes "may predispose [people] to increased cardiovascular risk" in the long run.
As a control, the researchers also had the men and women drink a placebo drink the next day, which tasted the same and contained the same amount of sugar and calories but didn't have all the stimulants found in Rockstar. The effects were found to be much less: with the placebo beverage, blood pressure rose just 3.3. points and stress levels about 30%.
So why are these buzzy beverages so harmful to our health? The study authors say that more research is needed to look into the effects of energy drinks, but some of the added stimulants in Rockstar are likely to blame — including caffeine, taurine, guarana, ginseng and milk thistle extract.
So next time you're tempted to reach for a Red Bull during an afternoon slump, consider the health impact of even just a few gulps — and turn to these natural, stress-free energy boosters instead.