An international study published in the Journal of American Medical Association found that energy drink consumption can lead to high blood pressure, increased heart rate, and serious cardiovascular risks. The study showed that even one energy drink can cause potentially harmful spikes in both stress hormone levels and blood pressure in young, healthy adults. Doctors warn that the risks are likely related to the excess caffeine and other stimulants in energy drinks. Frequent consumption of energy drinks can increase stress on the cardiovascular system and place chronic users at risk of heart problems.