Energy drinks significantly increase heart contraction rates in healthy young adults according to an ongoing study reported at the Radiological Society of North America (RSNA).
At the annual Chicago meeting Jonas Dörner MD from the University of Bonn’s cardiovascular imaging section, who is working on the study, said that until now, no-one had worked out the exact effects of energy drinks on heart functioning.
Citing concerns over possible adverse side effects of energy drinks on heart function, especially in adolescents and young adults, Dörner said there was “little or no regulation” of the US market.
Noting that caffeine levels in energy drinks are up to three times higher than in other caffeinated drinks including coffee or cola, Dörner said known side-effects included a rapid heart rate, palpitations, a rise in blood pressure “and in the most severe cases, seizures or sudden death”.
‘Significantly higher peak strain’
Dörner and colleagues used cardiac magnetic resonance imaging (MRI) to measure the effect of energy drink consumption on heart function in 18 healthy volunteers – 15 men and three women with an average age of 27.5 years.
Each subject was given one cardiac MRI before consuming an energy drink containing taurine (400mg/100ml) and caffeine (32mg/100ml), and another one hour after consumption.
The second MRI scan showed significantly higher peak strain and peak systolic strain rates (measures of ‘contractility’ or level of heart contraction) in the heart’s left ventricle.
This receives oxygenated blood from the lungs and pumps it to the aorta, which then distributes it throughout the rest of the body.
Long-term health risks ‘unknown’
Dörner said further studies are needed to understand how higher heart contractility affects daily activities or athletic performance, and to discover how long the effect of the drink lasts.
The team found no significant differences between baseline and second MRI scans in regard to volunteers’ heart rate, blood pressure or the amount of blood ejected by the left ventricle.
Dörner said that the long-term heart health risks linked to energy drinks are unknown, but advises that children and people with known cardiac arrhythmias, and says new studies are needed to assess the risk posed by energy drinks in tandem with alcohol.
The study is being led by Daniel Thomas, also from the University of Bonn, while other co-authors include Daniel Kuetting, Claas Naehle and Hans Schild.
The UK-based British Heart Foundation said it would not comment on unpublished research, when asked for its opinion on the reported study; quizzed as to whether greater heart contractility was necessarily a bad thing, the nations leading heart health charity referred us to links on heart palpitations (as a possible sign of heart problems) and atrial fibrillation as a major stroke cause.
The RSNA represents 53,000 radiologists, radiation oncologists, medical physicists and related scientists and publishes two peer-reviewed journals, Radiology and RadioGraphics.