Keto-friendly sweetener under scrutiny over possible stroke risk

The study, published in the Journal of Applied Physiology, reveals that this widely consumed ingredient reduces the vessels' capacity to dilate, elevates harmful oxidative stress, and compromises the body's natural ability to dissolve blood clots.

These cellular changes could potentially heighten the likelihood of stroke, even when consumed at typical dietary levels.

Erythritol is a sugar alcohol produced through the fermentation of corn, which received approval from the US Food and Drug Administration in 2001.

The sweetener now appears in hundreds of food products across the market.

Its appeal lies in its near-zero calorie content, delivering approximately 80 per cent of sugar's sweetness whilst having minimal impact on insulin levels.

This makes it particularly attractive to those managing their weight, controlling blood sugar, or following low-carbohydrate diets.

However, concerns about its safety are mounting.

A substantial study involving 4,000 participants across America and Europe found that those with elevated erythritol blood levels faced significantly higher risks of heart attack or stroke within three years.

To investigate the mechanisms behind this elevated risk, Professor Christopher DeSouza and graduate student Auburn Berry examined how the sweetener affects cells directly.

Their experiment exposed human brain blood vessel cells to erythritol concentrations equivalent to those found in a standard sugar-free beverage for three hours.

The findings showed that cells generated substantially less nitric oxide, which is essential for vascular relaxation, whilst producing more endothelin-1, which constricts blood vessels.

Additionally, the cells showed diminished capacity to create t-PA, a compound crucial for breaking down clots, alongside increased levels of damaging free radicals.

"Big picture, if your vessels are more constricted and your ability to break down blood clots is lowered, your risk of stroke goes up," said Berry.

"Our research demonstrates not only that, but how erythritol has the potential to increase stroke risk," Berry added.

Professor DeSouza noted that the experiment utilised only a single serving quantity, suggesting that those consuming multiple portions daily might experience more pronounced effects.

The researchers acknowledge their findings stem from laboratory cell experiments rather than human trials, meaning further investigation is necessary to confirm these risks in everyday settings.

Nevertheless, DeSouza advises consumers to scrutinise ingredient labels more carefully, looking specifically for erythritol or "sugar alcohol" listings.

"Given the epidemiological study that inspired our work, and now our cellular findings, we believe it would be prudent for people to monitor their consumption of non-nutrient-sweeteners such as this one," he said.