Taking energy drinks to heart

There was a time in human evolution when a drink was something you took from a stream or if you were feeling very outlandish might involve water with some powdered leaves in it. These days of course drinks come in any number of forms that are manipulated, tweaked, flavoured, coloured and spiked by marketers looking to make the drink that everyone will want. Once the marketers realised that the dream product had already been made and is called “water” they started marketing that as well. While water has been around for billennia there are some drinks that are relative newcomers to the market and among the newest are the “energy drinks”. These things masquerade as helpful energy boosters but in fact they can pack quite a punch for your heart.

Energy drinks tend to contain caffeine and the amino acid taurine. The amount of caffeine present is around three times that of the caffeine in usual soft drinks. Energy drinks may or may not be carbonated, and many also contain sugar or other sweeteners and herbal extracts. While teens were the original market for energy drinks the demographic of these commodities has broadened. Consumption within the global energy drink market surged by 14 per cent in 2011 to 4.8 billion litres, adding over 1.5 billion litres since 2007. Average growth over the past five years has been 10 per cent a year. These drinks are now pervasive so their impacts on the body are important. In the United States between 2007 and 2011 admissions to emergency wards as a result of energy drink consumption doubled from just over 10,000 to just over 20,000.

In a new study, energy drinks have been shown to significantly impact heart function.

The study involved healthy men and women with an average age of 27.5 years. The researchers took cardiac MRIs of the subjects both before and one hour after they consumed an energy drink that had 400mg/100ml of taurine and 32mg/100ml of caffeine. The MRIs showed that the energy drinks led to an increased peak strain and peak systolic strain rate in the left ventricle of the heart. The left ventricle received oxygenated blood from the lungs which it then pumps into the aorta for use in the body. There was no noted increase in heart rate, blood pressure, or blood volume pumped. So the results do not prove long term effects but they do show short term changes in contractility of the heart muscle.

So these energy drinks are no benign little thirst quenchers that give a lift to energy. They have real physiological effects.

They say that if it looks like a duck and quacks like a duck then it’s a duck. However, although energy drinks look like soft drinks there’s nothing soft about them (not that there’s much “soft” about “soft drinks” either for that matter).