Negative cardiovascular events such as angina and, cardiac arrhythmia
Over 50 million liters of more than 120 so called “energy drinks” have been consumed in 2011 in France. Due to their association to adverse events these drinks have recently raised national awareness in France. Energy drinks are sodas enriched with an array of substances already present in food, such as caffeine, taurine and vitamins. Each individual drink usually contains up to the caffeine content of two espressos. When taken in great quantity, they are suspected to induce a sensation of excitation and facilitate among others, serious adverse events in predisposed subjects.
Professor Milou-Daniel Drici, MD, University of Nice Sophia Antipolis, France and colleagues had examined adverse events that were reported to the ANSES; French Agency for Food, Environmental and Occupational Health & Safety.
In this study researchers examined adverse event reported to the agency between January 1, 2009 and November 30. 2012. Some 15 specialists including cardiologists, psychiatrists, neurologists and physiologists contributed to the investigation. The findings were compared to published data in the scientific literature.
The results showed that consumption of 103 energy drinks increased by 30% between 2009 and 2011 up to over 30 million liters in France, The leading brand made up 40% of energy drinks consumed. Two-thirds of drinks were consumed away from home.
During the two year period 257 adverse events that have been notified during the survey, 45 were excluded for lacking data leaving researcher s with 212 cases that had provided sufficient information.
The researchers found most of the adverse events reported were 95 cases cardiovascular in origin, 74 psychiatric and 57 neurological. Cardiovascular cases included cardiac arrests, sudden or unexplained deaths in 9 cases, and mainly other rhythm disorders in 43 cases. The other cases of cardiovascular events included angina 13 and hypertension 5.
Dr Drici said: "We found that 'caffeine syndrome' was the most common problem, occurring in 60 people. It is characterized by a fast heart rate (called tachycardia), tremor, anxiety and headache.’
Rare but severe adverse events were also associated with these drinks, such as sudden or unexplained death, arrhythmia and heart attack (myocardial infarction). Our literature search confirmed that these conditions can be related to consumption of energy drinks."
"Patients with cardiac conditions including catecholaminergic arrhythmias, long QT syndrome and angina should be aware of the potential danger of a large intake of caffeine, which is a stimulant that can exacerbate their condition with possibly fatal consequences,” adds Dr. Dric.
Professor Drici said: "So-called 'energy drinks' are popular in dance clubs and during physical exercise, with people sometimes consuming a number of drinks one after the other. This situation can lead to a number of adverse conditions including angina, cardiac arrhythmia (irregular heartbeat) and even sudden death."
He added: "Around 96% of these drinks contain caffeine, with a typical 0.25 litre can holding 2 espressos worth of caffeine. Caffeine is one of the most potent agonists of the ryanodine receptors and leads to a massive release of calcium within cardiac cells. This can cause arrhythmias, but also has effects on the heart's abilities to contract and to use oxygen. In addition, 52% of drinks contain taurine, 33% have glucuronolactone and two-thirds contain vitamins."
In conclusion the researchers write ““energy drinks” are associated with adverse events among which cardiovascular events. Due to a potentially strong under reporting bias, it seems necessary to inform certain predisposed subjects of such risks, as unknown amounts of caffeine resulting from “serial drinks” in dance clubs or during physical exercise, two popular yet particularly risky situations, could facilitate the emergence of complex cardiac arrhythmia's.”
In conclusion Dr. Drici states "The general public need to know that so-called 'energy drinks' have absolutely no place during or after physical exercise, as compared with other drinks designed for that purpose. When used in long alcoholic cocktails, the caffeine in 'energy drinks' enables young people in dance clubs or elsewhere to overcome the unwanted effects of alcohol, leading to an even greater intake of caffeine."
He concluded: "Patients rarely mention consumption of energy drinks to their doctors unless they are asked. Doctors should warn patients with cardiac conditions about the potential dangers of these drinks and ask young people in particular whether they consume such drinks on a regular basis or through binge drinking."