Energy drinks may lead to high BP and abnormal heart rhythm

Energy drinks are in trend nowadays and are increasingly consumed by teenagers owing to the instant boost up they provide. But researchers have been concerned about health risks associated with its use. A recent study published in the Journal of the American Heart Association has found that drinking 32 ounces of caffeinated energy drinks can lead to abnormal electrical activity of the heart and increase blood pressure. The electrical disturbances, in turn, can affect heart rhythm.

"Individuals with acquired or congenital long QT syndrome and those with hypertension (high BP) should be more vigilant and limit their energy drink intake," advise the authors.

The QT interval is a measurement of the time it takes ventricles in the heart (the lower chambers) to prepare to generate a beat again. If this time interval is either too short or too long, it can cause the heart to beat abnormally. The resulting arrhythmia can be life-threatening.

The consumption of energy drinks has been linked to an increase in emergency room visits and deaths. Sachin A. Shah, Thomas J Long School of Pharmacy and Health Sciences, University of the Pacific, Stockton, CA, and colleagues determined the impact of energy drinks on electrocardiographic and hemodynamic parameters in 34 young healthy volunteers aged 18 to 40 years.

The participants were randomly assigned to drink 32 ounces of one of two commercially available caffeinated energy drinks or r a placebo drink on three separate days. The drinks were consumed within a 60-minute period but no faster than one 16-ounce bottle in 30 minutes.

The electrical activity of the volunteers' hearts was measured through an electrocardiogram, which records the way a heart is beating. They also recorded the participant's blood pressure. All measurements were taken at the study's start and every 30 minutes for 4 hours after drink consumption.

Both energy beverages tested contained 304 to 320 milligrams of caffeine per 32 fluid ounces. Caffeine at doses under 400 milligrams is not expected to induce any electrocardiographic changes. Other common ingredients in the energy drinks in the study included taurine (an amino acid), glucuronolactone (found in plants and connective tissues) and B-vitamins. The placebo drink contained carbonated water, lime juice, and cherry flavoring.

Key Findings:

• In participants who consumed either type of energy drink, researchers found that the QT interval was 6 milliseconds or 7.7 milliseconds higher at 4 hours compared to placebo drinkers.


• The QT interval changes are generally sustained over the four-hour monitoring period rather than being a short-lasting effect after consuming 32-ounces of an energy drink.


• The researchers observed a statistically significant 4 to 5 mm Hg increase in systolic and diastolic blood pressure in participants who consumed the energy drinks.

"We found an association between consuming energy drinks and changes in QT intervals and blood pressure that cannot be attributed to caffeine. We urgently need to investigate the particular ingredient or combination of ingredients in different types of energy drinks that might explain the findings seen in our clinical trial," said Dr. Shah.

"Caffeinated energy drinks significantly prolong the QTc interval and raise brachial and central blood pressure post‐acute exposure. Further investigation is warranted on whether an individual ingredient or a unique combination leads to the observed electrophysiological and hemodynamic changes. The impact of long‐term energy drinks consumption remains unknown," concluded the authors.

For detailed study follow the link: https://doi.org/10.1161/JAHA.118.011318