Energy Drinks and How They Affect The Heart

Energy drinks are a multibillion-dollar industry that even beverage giants have invested in heavily. With the promise of an incredible energy boost, drink manufacturers have used anything from sugar, to caffeine, to vitamins and exotic compounds to create the hype. The result is that just one 8 oz can of popular energy drinks can deliver the caffeination effect of up to three or four coffees or teas – more than most would consume in a day. However, cans are getting larger and many consumers aren’t stopping at one serving.

While we know, intuitively, that this artificial stimulation has negative consequences, the effect on the heart has not been extensively studied. A well-controlled study of 34 young and healthy adults was conducted to see the effects of drinking 32 ounces of two popular energy drinks. Study participants were checked for heart rhythm and blood pressure anomalies versus the placebo control group. The study¹ is published in the June 4^th issue of the Journal of the American Heart Association.

Results of The Study

After recording blood pressure and electrical activity every 30 minutes over 4 hours, it showed that the QTc, or interval between heartbeats, had increased and blood pressure rose. While this study does not make a direct correlation between energy drinks and cardiac arrhythmias, we do know that prolonged QTc intervals are a primary risk factor for irregular heart rhythm. Whether consuming energy drinks, especially in significant quantities, actually causes lasting or permanent change of heart rhythm remains to be seen.

The Heart House’s Take

While the study participants were both young and healthy, the increase in QTc interval and blood pressure is still a concern. Long-term use and even abuse of energy drinks, which seems to be an ever-greater trend, may create an earlier and higher risk of heart disease in the future. According to the study, approximately 30% of teenagers drink energy drinks regularly.

It is well known that energy drinks can cause adverse heart effects, not least of which are heart attacks. Even after the immediate and mid-term effects of these drinks, there are the lifestyle effects of excess caffeine consumption including poor sleep, trouble focusing and longer-term withdrawal effects that can all adversely affect one’s health.

With this study, it becomes even more clear that patients with higher risk of cardiovascular disease or those with blood pressure issues should avoid energy drinks and instead derived their energy from daytime rest, prioritizing healthy levels of sleep at night and staying well hydrated – all of which can offer a similar energy boost and are all, in fact, protective factors against heart disease.

Also interesting is that this and three other studies, according to the study authors, have shown sustained increases in QTc interval after 32 ounces of energy drink consumption. Interestingly, 32 ounces, so far, seems to be the cutoff point as other studies evaluating the consumption of 16-24 ounces of energy drink consumption’s have shown generally fewer, if any heart-related side effects.

¹ Shah SA, Szeto AH, Farewell R, et al. Impact of High Volume Energy Drink Consumption on Electrocardiographic and Blood Pressure Parameters: A Randomized Trial. Journal of the American Heart Association. 2019;8(11). doi:10.1161/jaha.118.011318.