Energy Drinks Linked to Heart Problems in French Study

Author: European Society of Cardiology
Published: 31 Aug 2014 - Updated: 20 Oct 2026
Publication Type: Research, Study, Analysis

Table of Contents:
Synopsis - Definition - Overview - FAQs - Insights, Updates - Related Content

Synopsis

This research, presented at ESC Congress 2014 by Professor Milou-Daniel Drici, reviewed adverse events reported to ANSES, the French agency for food safety, between January 2009 and November 2012, after energy drinks were approved for sale in France. Of 257 reports, 212 were complete enough to evaluate, and 95 involved cardiovascular symptoms, including heart rhythm disorders, angina and at least 8 cardiac arrests or sudden or unexplained deaths. A panel of about 15 specialists, including cardiologists, psychiatrists, neurologists and physiologists, reviewed the cases and checked them against the published scientific literature, giving the findings more weight than isolated case reports. The work matters most for people living with heart conditions such as long QT syndrome, catecholaminergic arrhythmias or angina, for whom a large dose of caffeine can worsen symptoms, and it is useful for caregivers, parents of young adults and older readers managing cardiovascular disease who want to understand the real risks behind popular stimulant drinks.*

At a Glance

• 1 - Taurine was found in 52% of the energy drinks studied, and one-third contained glucuronolactone.
• 2 - A typical 0.25 liter can holds about as much caffeine as 2 espressos, and around 96% of energy drinks contain caffeine.
• 3 - Caffeine syndrome, marked by a fast heart rate, tremor, anxiety and headache, was the most common problem, affecting 60 people.
• 4 - Energy drink consumption in France rose 30% between 2009 and 2011 to more than 30 million liters, with two-thirds consumed away from home.

Topic Definition

Energy Drinks

Energy drinks are nonalcoholic beverages marketed to boost alertness, physical performance and stamina, typically through high doses of caffeine combined with sugar or sweeteners and additives such as taurine, glucuronolactone, guarana and B vitamins. Unlike sports drinks, which are designed to replace fluids and electrolytes lost during exercise, energy drinks act mainly as stimulants, and a single can may contain anywhere from about 80 to more than 300 milligrams of caffeine. In large or rapid doses, that caffeine can speed up the heart, raise blood pressure and trigger irregular heart rhythms, which is why energy drinks are a particular concern for children, teenagers, pregnant women and people with existing heart conditions.

Overview

Energy drinks can cause heart problems according to research presented at ESC Congress 2014 by Professor Milou-Daniel Drici from France.

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."

"Around 96% of these drinks contain caffeine, with a typical 0.25 liter 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 2008 energy drinks were granted marketing authorization in France. In 2009 this was accompanied by a national nutritional surveillance scheme which required national health agencies and regional centers to send information on spontaneously reported adverse events to the ANSES, the French agency for food safety."

The study analyzed adverse events reported to the agency between 1 January 2009 and 30 November 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 researchers found that consumption of the 103 energy drinks in France increased by 30% between 2009 and 2011 up to over 30 million liters. The leading brand made up 40% of energy drinks consumed. Two-thirds of drinks were consumed away from home.

During the study period 257 cases were reported to the agency, of which 212 provided sufficient information for food and drug safety evaluation. The experts found that 95 of the reported adverse events had cardiovascular symptoms, 74 psychiatric, and 57 neurological, sometimes overlapping. Cardiac arrests and sudden or unexplained deaths occurred at least in 8 cases, while 46 people had heart rhythm disorders, 13 had angina and 3 had hypertension.

Professor 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."

"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."

"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."

About the Study

The study was conducted at ANSES with the collaboration of the Center Regional de Pharmacovigilance de Nice, Alpes - Cote d'Azur, France.

Poster session 3: Emerging dietary concepts.

The European Society of Cardiology (ESC) represents more than 80,000 cardiology professionals across Europe and the Mediterranean. Its mission is to reduce the burden of cardiovascular disease in Europe.

ESC Congress is currently the world's largest international congress in cardiovascular medicine. ESC Congress 2014 takes place 30 August to 3 September at the Fira Gran Via congress center in Barcelona, Spain.

Frequently Asked Questions

NOTE: Researched FAQs by Disabled World (DW)

How much caffeine is safe for a healthy adult per day?

The U.S. Food and Drug Administration says up to 400 milligrams of caffeine a day, roughly four or five cups of brewed coffee, is not generally associated with dangerous effects in healthy adults. Sensitivity varies widely, and people with heart conditions, pregnant women and those taking certain medications may need much less.

How much caffeine is in a typical energy drink?

Caffeine content varies by brand and can size, ranging from about 80 milligrams in a small 250 milliliter can to 300 milligrams or more in some larger cans. Checking the label matters, because a single large can may approach the amount of caffeine many adults consume in a full day.

Should children and teenagers drink energy drinks?

The American Academy of Pediatrics advises that energy drinks have no place in the diets of children and adolescents because of their stimulant content and potential effects on the heart and nervous system. Water and milk remain the recommended drinks for young people.

What is the difference between an energy drink and a sports drink?

Sports drinks are designed to replace fluids, electrolytes and carbohydrates lost through sweat during exercise, while energy drinks rely on stimulants such as caffeine to increase alertness. Energy drinks can raise heart rate and are not a substitute for water or sports drinks during physical activity.

Why is mixing energy drinks with alcohol risky?

Caffeine can mask the sedating effects of alcohol, so people feel less drunk than they are and may drink more, take risks or drive while impaired. The combination also places extra stress on the heart and can increase the chance of dehydration and irregular heart rhythms.

What symptoms suggest too much caffeine from energy drinks?

Common warning signs include a racing or pounding heartbeat, jitters or tremor, anxiety, headache, nausea, trouble sleeping and dizziness. Chest pain, fainting, severe shortness of breath or an irregular heartbeat need emergency medical care right away.

Can energy drinks interact with medications?

Yes, caffeine can interact with stimulant medications used for ADHD, some asthma drugs, certain antibiotics and some heart medications, either increasing side effects or changing how the drugs work. Anyone taking regular medication should ask a pharmacist or doctor before using energy drinks.

Are sugar-free energy drinks safer for the heart?

Sugar-free versions cut calories and sugar but usually contain the same amount of caffeine and other stimulants, so the cardiac risks linked to high caffeine intake remain. People with heart conditions should treat them with the same caution as regular energy drinks.

Insights, Analysis, and Developments

Editorial Note: The French data is a useful caution rather than a reason for panic. Most people who have an occasional energy drink will not suffer heart harm, but the risk climbs when several cans are consumed in a row, when the drinks are mixed with alcohol, or when they are used in place of water or sports drinks during exercise. Mixing with alcohol is especially concerning because caffeine masks the feeling of being drunk, which can lead to more drinking and an even larger caffeine load. Because patients rarely mention these drinks unless asked, the findings put the onus on doctors to raise the subject, and on anyone with a heart rhythm disorder, high blood pressure or another cardiac condition to treat a can of energy drink as a real dose of stimulant rather than a harmless soft drink.*

Attribution/Source(s): This quality-reviewed publication was selected for publishing by the editors of Disabled World (DW) due to its relevance to the disability community. Originally issued as a press release by European Society of Cardiology and published on 31 Aug 2014. Last updated on 20 Oct 2026. This content may have been edited for style, clarity, or brevity.

* Editorial additions by Ian C. Langtree.