‘Energy drinks killed my superfit daughter’ claims heartbroken mum, as scientists sound alarm over cardiac risk

A distraught mother has warned of the dangers of energy drinks after her ‘super healthy’ 28 year-old daughter died following a shock heart attack — which she blames on the gym bunny’s caffeine habit.

Katie Donnell, from Florida in the US, took a caffeine supplement, followed by up to three energy drinks a day as well as the odd coffee, in order to fuel her workouts.

The teacher was ‘rarely’ seen without an energy drink in her hands, and would buy a four-pack of the sodas every two to three days, according to her boyfriend.

Apart from ‘horrible anxiety’, which her mother also blames on energy drink ‘abuse’, Ms Donnell was the ‘epitome of health’, suffering no underlying conditions.

But in August 2021, while out with friends, she suddenly fell unconscious, her eyes ‘rolling into the back of her head’.

‘They [her friends] thought she was having a stroke but she was actually having a heart attack,’ said her mother, Lori Barranon, 63.

‘The ambulance got there and couldn’t intubate her. She was without oxygen for too long and it caused brain damage.

‘They worked on her for three hours and she never woke up.’

 Doctors were so shocked by the attack that they initially believed it was the result of a drug spiking incident, Ms Barranon said.

‘She was left for 10 days in a medically induced coma but she never woke up.

‘Whenever she tried to wake up she was having seizures. Then her body started to fail.’

After an anxious bedside vigil, the family had to make the ‘horrible’ decision to switch off Ms Donnell’s life support machine.

‘At 28, you just don’t see people dropping dead of a heart attack,’ said Ms Barranon.

‘She was a workout queen, she ate real clean, she ate organic food, she was the epitome of health other than [having energy drinks].

‘Doctors said they see this happen a lot with people that do a lot of pre-workout or energy drinks but they wouldn’t give the cause of death to that.

‘I know for a fact that was what was wrong with her.’

Ms Barranon said her daughter would typically start the day with a ‘pre-workout’ supplement — which contains roughly the same amount of caffeine as an energy drink.

‘I didn’t realise how much she was drinking until after she passed. Her boyfriend said she would buy a four-pack [of drinks] every two to three days.

‘Not to mention she was drinking a lot of coffee and doing the pre-workout.

‘One of her friends said she’d hardly see Katie without an energy drink in her hands. When I cleaned out her car after she passed it was full of cans, at least three or four in there.

‘She thought it’d help her work out and give her more energy. She was working out, working full time and going to school, burning it at both ends.

‘I think she got used to the buzz.’

The consumption of energy drinks that contain high levels of caffeine can cause cardiovascular issues, including high blood pressure, heart arrhythmias and even heart attacks if drunk excessively, according to some studies.

While the recommended daily dose of caffeine is around 100 milligrams for adolescents and 400 milligrams for adults, some UK energy drinks contain more than 300 milligrams.

In the US, drinks containing more than 500milligrams of caffeine are available.

 A number of energy drinks also include additional ingredients such as taurine which, along with caffeine, are believed to contribute to alterations in heart rate, potentially disrupting the organ’s electrical system.

Last summer, researchers in the US warned that energy drinks could trigger a life-threatening cardiac arrest in those with genetic heart defaults — the majority of which are undiagnosed.   

Researchers at the Mayo Clinic in the US looked at the medical data of 144 patients who had survived a cardiac arrest and found seven of them had consumed an energy drink shortly before the attack. 

‘We would be remiss if we were not sounding the alarm,’ the scientists said. 

The Government has plans to introduce a ban on selling high-caffeine drinks to under 16s, according to the Labour manifesto.

Many supermarkets have already adopted a voluntary policy that stops teenagers from purchasing them.

Now, almost four years after her daughter’s death, Ms Barranon is urging others to stay away from ‘deadly’ energy drinks and calling for a ban.

‘If you don’t keep your kids away from this stuff you may be in my situation where your life is ruined. 

‘It’s so harmful and deadly, my whole family is affected by this.

‘I beg people to counsel your kids and watch what they’re doing, I thought I was.

‘I tell everybody I see with energy drinks that this is what it can do in the blink of an eye’

Ms Donnell is not the first energy drink fan believed to have suffered devastating consequences of her habit.

In August 2024, Zach Doran, 18, a healthy Oklahoma high schooler, suffered a fatal heart attack at the gym.

His girlfriend attributed the shock attack to his relentless use of caffeine products. 

He had been in the habit of using both pre-workout supplements and energy drinks before going to the gym.

‘[H]e was the healthiest person that I knew in my life and I can say confidently that he was the healthiest person in the majority of people’s lives he was apart of,’ Ms Gilmore said in a June Facebook post.

‘Because he was so healthy and fit i never really thought much of it. although knowing the dangers of energy drinks and how they can cause heart problems I never thought Zach would be a part of this.’

A small 2018 study suggested that consuming just one energy drink could increase your risk of heart attack and stroke in 90 minutes.

Researchers from the University of Texas at Houston said the drinks narrow blood vessels, which restricts blood flow to vital organs.

The team suggested that the negative effect on blood vessels could be related to the effects of ingredients in the energy drinks — including caffeine, taurine, sugar and other herbals.