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Can Energy Drinks Cause Stroke? Caffeine’s Impact on Heart Health

May 04, 2023
Cans of energy drinks, which may cause increased risk of stroke

Eat this, not that. Drink this, not that. What’s a person to think? One day something is good for you, then another study a year later says it’s not.

Now caffeine, the popular stimulant in a person’s daily cup of joe, is under scrutiny again, but this time in relation to energy drinks and energy shots and an increased risk for stroke. Energy shots are a concentrated form of energy drinks, which contain caffeine and other substances like energy drinks, but in smaller volumes.

A stroke, also known as transient ischemic attack or cerebrovascular accident, happens when blood flow to the brain is blocked, preventing the brain from getting oxygen and nutrients from the blood needed to keep brain cells alive.

“There is a [lack] of research data on the topic of whether energy drinks can cause an ischemic stroke. While there is no definitive study offering proof to that effect, scientists have found possible links between the two,” said Dr. Melissa Mercado of the Neurology Division at Baystate Health.

“What we as doctors are certain of is that drinking excessive amounts of caffeine increases your heart rate and blood pressure, and that high blood pressure is the leading risk for stroke,” she added.

Caffeine’s Impact on the Body

Caffeine is a stimulant which occurs naturally in the seeds, nuts and leaves of various plants, including coffee beans, tea leaves, cocoa beans, kola nuts and guarana seeds.

Energy drinks contain large amounts of caffeine, the biggest culprit, as well as added sugars and other stimulants such as guarana, taurine and I-carnitine. The National Institutes of Health notes that 70 to 240 milligrams of caffeine can be found in a 16-oz drink and 113 to 200 milligrams in an energy shot.

For healthy adults, the Food and Drug Administration cites 400 milligrams a day - equal to about 4-5 cups of coffee - as relatively safe from harmful health effects. And the American Academy of Pediatrics recommends that adolescents aged 12-18 should not exceed 100 mg per day or an average cup of coffee. They also go as far as to say that “caffeine and other stimulants contained in energy drinks have no place in the diet of children and adolescents.”

Energy Drinks and Health Problems

Stroke is not the only heart health issue to worry about when considering energy drinking consumption. A variety of studies found issues with high blood pressure, electrical disturbances in the heart, and even cardiac arrest tied to energy drink consumption.

The Cleveland Clinic notes that energy drinks can cause anxiety, high blood pressure, heart palpitation, and caffeine intoxication and withdrawal in young people. They go on to say that while adolescents may use energy drinks to study, long-term mega-doses of caffeine are not good for the brain.

A small study published in the Journal of the American Heart Association found that drinking 32 ounces of an energy drink in a short timespan may increase blood pressure and the risk of electrical disturbances in the heart, which affects heart rhythm. The 32 ounce serving included 304-320 milligrams of caffeine, well below the 400 milligram limit that federal guidance says should not cause electrocardiographic changes.

In what is believed to be the first reported case of energy drinks leading to a stroke, the American Journal of Emergency Medicine in 2012 detailed a case where a patient had ischemic stroke and epileptic seizure after intake of energy drinks with alcohol. The CDC advises against combining alcohol and caffeine, but notes that it is a common practice in high school students and young adults and often contributes to binge drinking.

In some European countries, energy drinks have been banned after the death of a healthy Irish teenager. A paper published by Rutgers University [opens as PDF] shares the story of the student’s death before a basketball game. After consuming four cans of a popular energy drink, the student died from cardiac arrest. The paper also noted that although studies cannot prove that energy drinks directly cause such hazards as diabetes, seizures, cardiovascular issues, and mood changes in consumers, they can correlate the energy drinks to each of those cases and to seizures and stroke.

Reducing Your Risk

According to the National Institutes of Health National Center for Complementary and Integrative Health, energy drinks are the most popular dietary supplement consumed by American teens and young adults. Men between the ages of 18-34 consume the most energy drinks, and almost one-third of teens between the ages of 12-17 drink them regularly.

Consider the popular phrase - “Everything in moderation.”

“Since many Americans today are often known for their overconsumption of food and beverages, including energy drinks, doctors often recommend that adults drink no more than one can a day, with many pediatricians agreeing that even a single can may be too much for children and younger adults,” said Dr. Mercado.

The Baystate neurologist noted that chugging down too many energy drinks can lead to a condition called reversible cerebral vasoconstriction syndrome (RCVS) which can result in the risk of stroke, noted Dr. Mercado.

“RCVS causes a narrowing of the blood vessels in the brain, which can restrict its blood supply. Its main symptom is a sudden, severe headache, often referred to as a ‘thunderclap headache,’ unlike you’ve ever experienced,” she said.

“While many Americans turn to energy drinks to improve their concentration and reduce fatigue, as well as to enhance their physical performance, regular coffee is likely a safer alternative with less additives and sugar that could lead to other health problems,” said Dr. Mercado.

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