Caffeine-loaded energy drinks may make your blood vessels less efficient. Researchers examined the blood vessels of 44 healthy, non-smoking medical students both before and after they consumed a 24-ounce energy and found that after finishing the energy drink, the internal diameter of the participants’ blood vessels became dramatically smaller. Lead researcher Dr. John Higgins explains, “It’s more work for the heart and less oxygen supply for the heart. This could explain why there have been cases where kids have had a cardiac arrest after an energy drink.”
American Heart Association, November 2018