* FOR PRESERVATION PURPOSES ONLY * Credit: Warren Simons

A new study done by Dr Anna Svatikova from the Mayo Clinic, and her team, found out that having just one energy drink at a time can cause noteworthy momentary health changes in healthy adults, that could over time increase the risk of heart conditions.

Researchers recruited 25 healthy subjects (aged 18 years or more) to consume one can of a 16 ounce (480 millilitre) Rockstar energy drink and a placebo drink in the course of 5 minutes in a random order on 2 separate days, that weren’t more than 14 days apart. The placebo drink had similar texture, taste and colour as the energy drink, but did not contain any caffeine or other stimulants that are found in the Rockstar energy drinks (according to the study one such drink contains 240 mg caffeine, 2,000 mg taurine, extracts of ginseng roots, guarana seeds and milk thistle) – it should be noted that even though this study focused on one brand, there are dozens of different brands of energy drinks, the majority of them having related chemical structure which would probably replicate a very similar results.

The team investigated the effects of consuming energy drink on hemodynamic differences prior and after the consumption (such as heart rate and blood pressure). Partakers were asked to not eat anything and not drink any alcohol and caffeine 24 hours before each study day. They measured norepinephrine levels (norepinephrine or noradrenaline is activated by the adrenal glands and is responsible for blood pressure and heart rate spikes), glucose and blood levels of caffeine, along with blood pressure and heart rate before and 30 minutes after drink intake.

The serum levels of caffeine remained the same after drinking placebo, but increased greatly after drinking the energy drink. Consumption of the energy drink caused a 6.2% increase in systolic blood pressure (from 108.4 mm Hg to 115.0 mm Hg) vs a 3.1% increase with the placebo drink (from 108.3 mm Hg to 111.6 mm Hg). Diastolic blood pressure increased by 6.8%, but remained the same with the placebo. Average blood pressure increased by 6.4% with energy drink (74.2 mm Hg to 78.9 mm Hg) and only 1% with a placebo (from 74.9 mm Hg to 75.4 mm Hg). Heart rate showed no apparent increase. Norepinephrine levels were also affected after energy drink; levels increased from 150 pg/mL to 250 pg/mL. After drinking a placebo there was only a minor increase; from 140 pg/mL to 179 pg/mL, making the change rate was quite noticeable: a 74% increase after energy drink versus 31% after a placebo drink.

The authors noted:

“These acute hemodynamic and adrenergic changes may predispose to increased cardiovascular risk. Further research in larger studies is needed to assess whether the observed acute changes are likely to increase cardiovascular risk.”

The consumption of energy drinks has already been linked to severe cardiovascular cases, due to intake of larger amounts of caffeine and other stimulants. In the years 2007 to 2011, most cases were reported to concern adults aged from 18 to 25, the number of ER visits linked to energy drinks almost doubled in the US, increasing from a bit over than 10,000 to nearly 21,000.

A study carried out earlier this year, involving young people who had experienced a traumatic brain injury episode, found they were 7 times more likely to have had at least 5 energy drinks in the week prior to the event.

The results have been published in the Journal of the American Medical Association as:“A Randomize Trial of Cardiovascular Responses to Energy Drink Consumption in Healthy Adults”.