Study Links Energy Drink Overuse to Strokes

Researchers evaluated a man in his 50s who had a stroke after reporting that he drinks an average of eight energy drinks a day

Juliette Fairley

Published: 12/18/2025, 4:33:53 PM EST

Study Links Energy Drink Overuse to Strokes — A red bull and other energy drinks in a shelves of a supermarket, in Bourgueil, France, on Dec. 26, 2024. (Magali Cohen/ Hans Lucas via AFP)

A research paper evaluating the consumption of energy drinks considers the beverage a risk for stroke and cardiovascular disease.

The Energy Drinks, Hypertension and Stroke study evaluated a man in his 50s who reported drinking an average of eight energy drinks a day, each containing 160 mg caffeine, before landing in the hospital due to an ischemic thalamic stroke.

“On cessation of this consumption, his [blood pressure] normalized and antihypertensives were successfully withdrawn,” study authors wrote.

WebMD describes a thalamic stroke as a blood clot that blocks an artery above the brain stem.

Most energy drinks are promoted as energy boosters and are mixed with large amounts of caffeine, sugar, and other stimulants like taurine, guarana, or B vitamins.

“Consuming large quantities of energy drinks can stress the blood vessels in a way comparable to stimulant drug use, making serious medical outcomes unsurprising,” board-certified neurologist Jeremy Liff told NTD.

In the case study, the stroke emerged on the patient’s left side with symptoms of weakness, numbness, and clumsiness. The patient’s blood pressure on admission to the hospital was 254 over 150 mmHg.

A Baptist Health chart shows that normal blood pressure for a man in his 50s is about 124 over 77 mmHg.

“There is no safe number of energy drinks to consume defined by age,” Dr. Liff added. “Risk is driven by dose and frequency, not age alone. Even younger individuals can experience serious consequences if they consume energy drinks excessively or regularly.”

Popular brands of energy drinks include Red Bull, Monster, Celsius, Bang, Ghost, and Rockstar.

The potential for the case study to focus attention on the invisible risks of consuming too many energy drinks is what interests integrative pharmacist and certified nutrition specialist Lara Zakaria the most.

“This case highlights something we didn’t have to contend with 30–40 years ago, which is that it’s now possible to consume pharmacologic doses of caffeine and stimulants routinely, without realizing it,” Zakaria told NTD. “Blood pressure can climb quietly until you’re in crisis. This case is a dramatic example.”

In addition to the caffeine, Zakaria wishes that consumers would pay attention to sugar content in energy drinks.

National Institutes of Health (NIH) data estimates that energy drinks can contain up to 80 grams of sugar per can, depending on the brand, and up to 500 milligrams of caffeine.

"In the context of high caffeine, sugar can further amplify blood pressure and vascular stress," Zakaria added. "But sugar-free doesn’t mean risk-free. Artificially sweetened energy drinks still deliver high stimulant loads."