How Energy Drinks May Affect the Heart

By Tracy Hampton

Beth Israel Deaconess Medical Center correspondent


The hectic pace of modern life can make it seem hard to keep up. Some may try turning to energy drinks, which are purported to provide mental and physical stimulation, to help stay revved up and alert. But how safe are they, particularly for the heart?


“Energy drinks contain a variety of substances, and most research suggests that the only active ingredient is caffeine,” says Dr. Alfred Buxton, Director of the Clinical Electrophysiology Laboratory in the CardioVascular Institute at Beth Israel Deaconess Medical Center. “Many also contain sugar or other sweeteners, herbal extracts, and amino acids.”


Dr. Buxton adds that caffeine consumption in moderation is safe for most people, but some individuals who have a predisposition to cardiac arrhythmias may be sensitive to high doses of caffeine.


“Most rhythm abnormalities that develop in response to caffeine are not dangerous. However, there are rare conditions in which caffeine may precipitate dangerous cardiac arrhythmias,” he explains. “Also, large doses of caffeine can raise blood pressure transiently, which may be harmful to some individuals.”


For most healthy adults, consuming 200 to 300 milligrams of caffeine per day isn’t harmful. Over-consuming caffeine is less likely with coffee or soda, which are typically consumed more slowly than gulping down a shot of an energy drink. In addition, it can be difficult to determine how much caffeine is in a particular energy drink.


A recent Consumer Reports investigation that tested 27 popular energy drinks found that 11 did not list the amount of caffeine on the label. Among the 16 products that did, five had 20 percent more caffeine than the label claimed, and one had about 70 percent less. Caffeine levels per serving ranged from about 6 milligrams to 242 milligrams per serving, and some containers had more than one serving. By comparison, a typical 8-ounce cup of coffee has about 100 milligrams, while a can of soda has about 35.


The U.S. Food and Drug Administration also recently released reports about deaths and injuries that may have possible links to several top-selling energy drinks. And, a report by the federal Substance Abuse and Mental Health Services Administration found that more than 13,000 emergency room visits in 2009 were linked to energy drinks, which is a ten-fold jump from the number of such visits reported in 2005.


“Bottom line — people can probably get the same effects as energy drinks in a safer form, and for much less money, by drinking coffee or other standard beverages instead of energy drinks,” says Dr. Buxton.


Above content provided by the CardioVascular Institute at Beth Israel Deaconess Medical Center. For advice about your medical care, consult your doctor.


Posted January 2013