Just One Energy Drink May Boost Heart Disease Risk in Young Adults

09 Nov 2015 --- Drinking one 16-ounce energy drink boosts blood pressure and stress hormone responses in young, healthy adults, according to a study presented at the American Heart Association’s Scientific Sessions 2015. These changes could conceivably trigger new cardiovascular events.

Researchers studied 25 healthy young adults with no known cardiovascular risk factors. Each drank one 16-ounce can of a commercially available energy drink or a sham drink in random order on two separate days.

Researchers measured participants’ blood pressure and blood levels of norepinephrine (adrenaline) before and 30 minutes after drink consumption. Norepinephrine is a “fight or flight” chemical that increases blood pressure and the heart’s ability to contract and it modulates heart rate and breathing in response to perceived stress.

Researchers found that in addition to increases in blood pressure after consuming the energy drink, participants’ norepinephrine levels increased more than twice as much when compared to those who drank the sham drink. Specifically, norepinephrine levels increased by almost 74 percent after the energy drink consumption, versus by 30 percent after the sham drink.

Researchers said their findings suggest increases in blood pressure and stress hormones could predispose otherwise healthy, young adults to increased cardiovascular risk.

Overexertion of the heart muscle caused by an increase in adrenaline can cause the heart muscle to wear down. The Substance Abuse and Mental Health Services Administration said that 20,783 people visited emergency rooms in the USA in 2011 and that 10% of these required hospitalization. The dramatic effects on the heart rate is thought to be due to the combination of very high sugar, caffeine and taurine content in most of the drinks.

A study in 2012 used MRI scanning to assess the effects of energy drinks containing caffeine and taurine on heart rate and found that heart contraction rates increased an hour after consuming the drinks. When drinks containing only caffeine and sugar were tested, heart rates did not alter. The authors theorized that the effects on adrenaline and thus heart contractions came from the combined effect of caffeine and taurine, although it may come from taurine alone. However taurine is used in medicine for congestive heart failure and lowers blood pressure, so the effects are likely to be from a combination of the ingredients, including the high sugar levels.

Caffeine also causes increases in blood pressure, especially if consumed in large amounts and in people who do not usually consume it. Anna Svatikova, a cardiovascular-diseases fellow at the Mayo Clinic in Rochester, Minnesota and the leader of this study, noted that the effects on blood pressure were most dramatic in people who did not usually consume caffeine.

"Now we are seeing that for those not used to caffeine, the concern may be even greater. Consumers should use caution when using energy drinks because they may increase the risk of cardiovascular problems, even among young people," said Svatikova.

While caffeine is usually the ingredient to get the blame for adverse effects, scientists do not yet fully understand which may be to blame and so further research is needed. In the meantime, avoiding consuming energy drinks on a regular basis may be advisable.