Emerging concerns have arisen regarding sugar-free energy drinks, ice creams, and protein bars, as a revisited study indicates they might elevate the risk of potentially fatal strokes.

At the University of Colorado, scientists conducted laboratory tests where they introduced human cells to erythritol, a sugar substitute, in concentrations similar to those found in diet sodas.

The findings revealed that within a mere three hours, the cells exhibited concerning changes, particularly in the blood-brain barrier. This critical barrier serves as the brain’s defense mechanism, filtering out harmful substances while allowing essential nutrients to pass through.

A significant decline was observed in the release of proteins that play a vital role in dissolving clots, an essential process for stroke prevention.

Moreover, the study noted that blood vessel cells became perilously constricted, increasing the likelihood of blockages from clots, potentially leading to strokes or impairing the brain’s oxygen and nutrient supply.

This cautionary note about erythritol, found in products like zero-sugar Monster Energy drinks, Halo Top ice creams, and certain Quest protein bars, comes amid a puzzling increase in stroke incidents among younger individuals. According to the CDC, stroke cases have surged by nearly 15% among young adults since 2011.

Auburn Berry, a graduate student who led the research, said in a press release: ‘While erythritol is widely used in sugar-free products marketed as healthier alternatives, more research is needed to fully understand its impact on vascular health.

‘In general, people should be conscious of the amount of erythritol they are consuming on a daily basis.’

Health experts are warning over a sweetener found in diet sodas, ice creams and protein bars (stock image)

The above graphic shows foods that contain the sweetener erythritol

Although the new study was small and used cells outside the human body, it added to the growing body of evidence raising concerns over sweeteners.

The study was published in July last year, but has resurfaced this week in scientific reports online.

In the paper, published in the Journal of Applied Physiology, researchers found that cells suffered damage after being exposed to erythritol and that, in some cases, the cells died.

In particular, the sweetener was found to sabotage the cell’s ability to release a protein that breaks up clots when they form, which would normally slash the risk of a stroke.

In their conclusion, researchers said the sweetener ‘potentially contributes to [an] increased risk of ischemic stroke’.  

An ischemic stroke occurs when a blood clot blocks a blood vessel in the brain, preventing blood and oxygen from reaching brain tissue. This can cause brain cells to die within minutes.

About 700,000 Americans suffer from this stroke every year.

Among the products that contain erythritol is Monster Energy Zero Ultra, that is pictured above

The research also has limitations, however. The tests were conducted on isolated cells in a lab rather than in a complete blood vessel, which means the cells may have behaved differently. 

Scientists say that more sophisticated testing will be needed to confirm the potential effects of erythritol on the human body.

Erythritol differs from other sweeteners because it is a sugar alcohol and is naturally made in small amounts in the human body. It is about 80 percent as sweet as sugar.

For comparison, major sweeteners aspartame and sucralose are made artificially in a lab and are up to 600 times sweeter than sugar.

Sugar alternatives help people to reduce their sugar intake and potentially lose weight without giving up sweet tastes. 

Some studies have, however, raised concerns over potential cell damage and claimed they could change the human microbiome, which could actually cause more weight gain.

It is used in a number of zero calorie energy drinks. Above is a stock photo of energy drinks

The research was just the latest to warn over the risks of erythritol after several large-scale studies found people who regularly consume the sweetener have a higher risk of heart disease and strokes.

In a 2023 study on more than a thousand patients, researchers found that those with the highest blood levels of erythritol were twice as likely to suffer from a major cardiac event, such as a stroke, compared to those with the lowest levels.

Health and Human Services Secretary Robert F Kennedy Jr has already taken aim at artificial sweeteners, calling them ‘poison’, but he has not previously railed against erythritol.

At a press conference in April, he said: ‘I don’t think we are going to be able to eliminate sugar.

‘But I think what we need to do, probably, is give Americans knowledge about how much sugar is in their products, and also, with the new nutrition guidelines, we’ll give them a very clear idea about how much sugar they should be using, which is zero.’