Can energy drinks affect your heart? New study raises concerns for young adults

Energy drinks and other stimulant-containing products have been linked to a higher proportion of reported heart problems in young adults, according to preliminary US research presented in November 2026. The analysis found more reports of serious cardiovascular events involving products with caffeine or other stimulants, particularly among adults aged 18 to 34. However, the findings do not establish that energy drinks directly cause heart attacks. Understanding the difference between an association and a proven risk is essential, especially when deciding how much caffeine to consume.

What did the new study find about energy drinks and heart health?

Researchers presenting their findings at the American Heart Association’s Scientific Sessions 2026 in Chicago examined 28,345 reports of possible adverse events submitted to a US Food and Drug Administration safety database between 2017 and 2025. Of these, 854 involved energy drinks or dietary supplements containing caffeine or other stimulants. The findings were described in an American Heart Association research announcement published on November 2, 2026.

Compared with reports involving products without these stimulants, reports associated with caffeine- and stimulant-containing products mentioned cardiac arrest about 11 times more often, heart attacks about 4.5 times more often, and ventricular arrhythmias or heart palpitations about 4 times more often. Researchers also observed more frequent reports of increased heart rate, chest pain and fainting.

Approximately 45% of the cardiovascular reports associated with these products involved adults aged 18 to 34. This finding attracted attention because serious cardiovascular events are generally less common in younger adults than in older age groups.

Can energy drinks cause a heart attack?

The study does not prove that energy drinks cause heart attacks. It examined voluntarily submitted adverse-event reports, which record health problems reported in connection with products. A report does not establish that the product caused the event.

The analysis also included stimulant supplements alongside energy drinks. Some products contained ingredients other than caffeine, including various plant extracts and stimulant compounds. The findings therefore cannot be applied equally to every energy drink sold in supermarkets or convenience stores.

Another major limitation is the absence of reliable information about how many people consumed these products without experiencing an adverse event. This means the study cannot calculate a person’s absolute risk of having a heart attack after drinking a can.

The findings were presented as a conference abstract and had not yet been published as a full peer-reviewed paper. They provide a reason for further investigation and improved safety monitoring, rather than proof that occasional energy drink consumption causes cardiovascular disease.

How much caffeine is in an energy drink?

Caffeine content varies considerably between brands, formulas and serving sizes. According to the European Food Safety Authority’s caffeine assessment, a typical 250 ml energy drink contains approximately 80 mg of caffeine, similar to the amount in a 60 ml espresso. Actual amounts may differ.

For example, a drink containing 32 mg of caffeine per 100 ml would provide 80 mg in a 250 ml can and 160 mg in a 500 ml can. In US measurements, 250 ml is approximately 8.5 fluid ounces, while 500 ml is approximately 16.9 fluid ounces.

US energy drinks can vary substantially in strength. The US Food and Drug Administration’s guidance on caffeine describes a broad range of caffeine amounts across different energy drink products. The best approach is to check the amount listed for the entire container, rather than assuming all cans contain similar doses.

Coffee, tea, cola, chocolate, certain medications and dietary supplements can also contribute to total caffeine intake. Drinking an energy drink after several coffees may therefore increase daily exposure more than expected.

How much caffeine is considered safe for adults?

For most healthy adults, the FDA cites 400 mg of caffeine per day as an amount not generally associated with negative effects. EFSA reaches a similar conclusion for healthy adults when caffeine is consumed throughout the day and identifies 200 mg as a reference level for a single dose.

These amounts are not targets to aim for, and they do not guarantee that everyone will tolerate caffeine equally well. Individual sensitivity, medical conditions, medications and the timing of consumption all matter.

Some people experience a racing heartbeat, palpitations, anxiety, restlessness or disrupted sleep at lower doses. EFSA also notes that 100 mg of caffeine consumed close to bedtime may affect sleep in some adults.

During pregnancy, EFSA identifies 200 mg per day from all sources as a reference level. People who are pregnant, breastfeeding, taking medications or managing cardiovascular conditions should seek advice appropriate to their circumstances rather than relying solely on general adult guidance.

Are energy drinks suitable for children and teenagers?

Energy drinks are not recommended for children and teenagers by US paediatric medical experts, according to the FDA. Concerns include their caffeine content and the potential for sleep problems, anxiety, increased heart rate and palpitations.

In the UK, drinks containing more than 150 mg of caffeine per litre must carry a high-caffeine warning, subject to specific exceptions for certain coffee and tea products. The label must also identify the caffeine concentration. These requirements are explained in the UK government’s food labelling guidance.

UK authorities have also considered restrictions on sales of high-caffeine energy drinks to children. However, a government consultation or proposal should not be confused with a nationwide ban already in force. Retailers may operate their own age-related sales policies.

Although EFSA provides a weight-based caffeine reference level for children and adolescents, it should not be interpreted as encouragement to consume energy drinks. Sleep, individual sensitivity, existing health conditions and caffeine from other foods and drinks also need to be considered.

How to check caffeine on an energy drink label

Start by checking the caffeine amount and the container size. On UK labels, caffeine concentration is commonly expressed in milligrams per 100 ml. If a drink contains 32 mg per 100 ml, a 500 ml can provides 160 mg in total.

In the United States, caffeine amounts may be displayed per serving or per container, and labelling practices vary between products. Check whether a package contains more than one serving, and look for information about the total caffeine content from all sources.

Ingredients such as guarana may contribute additional caffeine. It is also worth checking added sugars and other stimulant ingredients. A sugar-free energy drink can still contain a substantial amount of caffeine, while added vitamins do not cancel out the effects of stimulants.

Should you drink energy drinks before exercise or with alcohol?

Energy drinks should not be confused with sports hydration drinks. Products designed for hydration during exercise may provide fluids and electrolytes, whereas energy drinks are generally marketed for their stimulant effects. An energy drink is not automatically an appropriate replacement for water during physical activity.

Combining energy drinks with pre-workout supplements can increase total stimulant exposure. Mixing them with alcohol is also a concern because feeling more alert does not mean that alcohol-related impairment has disappeared.

People with heart rhythm problems, high blood pressure or other cardiovascular conditions should discuss high-caffeine products with a healthcare professional before consuming them.

What symptoms should energy drink consumers watch for?

Excessive caffeine intake can cause a rapid heartbeat, palpitations, nervousness, sleep disturbances, nausea and other symptoms. These effects do not necessarily indicate a serious heart condition, but recurring symptoms deserve medical attention and a review of caffeine consumption.

Severe chest pain, fainting or difficulty breathing should be treated as possible medical emergencies and assessed urgently.

The new American study does not establish that drinking one energy drink causes a heart attack. It does, however, highlight why caffeine intake deserves attention, particularly when several stimulant products are consumed together. Checking the label, accounting for caffeine from all sources and recognising individual health considerations are practical ways to make more informed choices.