Higher consumption of low-calorie sweetener linked to greater heart attack, stroke risks: US study

NEW YORK – A low-calorie sweetener called xylitol, which is used in many reduced-sugar foods and consumer products, may be linked to an increased risk of heart attack, stroke and death in people who consume higher amounts of it, a new study has found.

“Humankind has not experienced levels of xylitol this high except within the last couple of decades, when we began ingesting completely contrived and sugar-substituted processed foods,” said senior study author Stanley Hazen, director of the Centre for Cardiovascular Diagnostics and Prevention at the Cleveland Clinic Lerner Research Institute.

In 2023, the same researchers found similar results for another low-calorie sweetener called erythritol, which is used as a bulking sugar in stevia, monkfruit and keto reduced-sugar products.

Additional lab and animal research presented in both papers revealed erythritol and xylitol may cause blood platelets to clot more readily. Clots can break off and travel to the heart, triggering a heart attack, or to the brain, leading to a stroke.

In the new study on xylitol, “differences in platelet behaviour were seen even after a person consumed a modest quantity of xylitol in a drink typical of a portion consumed in real life”, said Dr Matthew Tomey. The cardiologist at Mount Sinai Fuster Heart Hospital in New York City is not involved in the study.

“These experiments are interesting but alone do not prove that platelet abnormalities are to account for a linkage between xylitol and clinical events,” added Dr Tomey, who is also an assistant professor of medicine at the Icahn School of Medicine at Mount Sinai.

Some 61 per cent of American adults will have cardiovascular disease by 2050, according to a recent prediction by the American Heart Association.

Reducing clotting activity is a key treatment used by cardiologists, so any additional clotting in platelets is a bad sign, said Dr Andrew Freeman, director of cardiovascular prevention and wellness at National Jewish Health in Denver.

“When someone has a heart attack, we give them aspirin or drugs like clopidogrel, or Plavix, to counter platelet activity. These sugar alcohols appear to be enhancing platelet activity, which is concerning,” said Dr Freeman, who is not associated with the new research.

“This is another warning we ought to switch to water, with a close second being unsweetened tea or coffee,” he added.

Ms Carla Saunders, president of the Calorie Control Council, an industry association, told CNN that the study results are “contrary to decades of scientific evidence substantiating the safety and efficacy of low-calorie sweeteners such as xylitol by global health and regulatory agencies”.

“These findings are a disservice to those who rely on alternative sweeteners as a tool to improve their health.”

As sweet as sugar with less than half the calories, xylitol is often used in sugarless gum, breath mints, toothpaste, mouthwash, cough syrup and chewable vitamins. It is frequently added in larger quantities to candy, baked goods, cake mixes, barbecue sauces, ketchup, peanut butter, puddings and pancake syrup.

Xylitol is a sugar alcohol, a carbohydrate found naturally in foods such as cauliflower, eggplant, lettuce, mushrooms, spinach, plums, raspberries and strawberries. The amount of xylitol found in such natural sources is tiny, Dr Hazen said.

“If you actually do the calculation, it literally takes a tonnage of fruit to be equivalent to one diabetic cookie that can have like 9g of xylitol, which is a typical label amount,” he noted.

For commercial use, however, xylitol is made from corncobs, birch trees or genetically engineered bacteria.

Dr Hazen noted that many professional associations also recommend xylitol as a sugar substitute for patients with obesity, diabetes or pre-diabetes to improve glycaemic control.

“Yet people at risk for diabetes are among the most vulnerable for clotting events,” he said. “We’re targeting the wrong people.”

Exposure has increased over the last two decades, Dr Hazen added, because the US Food and Drug Administration recognises sugar alcohols as Gras or “generally recognised as safe”.

“Xylitol is cheaper to make than cane sugar, and so more and more keeps getting incorporated as a sugar substitute into food. Some 12-ounce (350ml) drinks that use xylitol as a major artificial sweetener can contain 30g or more,” he said.

“You can even buy it in bulk at the grocery store where you’re told to use it as a one-to-one substitute for sugar in home cooking.”

Research has shown some artificial sweeteners may create a backlash in the metabolic system, triggering the body to expect more calories, thus making weight loss more difficult.

The study, published on June 6 in the European Heart Journal, began as a way of finding unknown chemicals or compounds in a person’s blood that might predict the risk for a heart attack, stroke or death within the next three years.

Dr Hazen and his team analysed 1,157 blood samples from people undergoing assessment for heart disease that had been collected between 2004 and 2011. They also examined another batch of blood samples from more than 2,100 people who may also have had high risk for heart disease.

They found a number of alcohol sugars that appeared to have an impact on cardiovascular function, including xylitol and erythritol. Erythritol is the predominant ingredient by weight in many stevia and monkfruit products.

The February 2023 erythritol study found the risk of heart attack and stroke nearly doubled within three years when people had the highest levels of erythritol in their blood.

For the new study on xylitol, the results were basically the same – people with the highest levels of xylitol, compared with those with the lowest levels, had nearly twice the risk of heart attack, stroke and death, Dr Hazen said.

“There’s a receptor on our platelets, which we as yet don’t understand, that is recognising this molecule and signalling to the platelet to be more prone to clot,” he added.

“Our taste buds can’t tell the difference in the structures between sugar and these other sweeteners, but clearly our platelets can.”

The World Health Organisation warned consumers in 2023 to avoid artificial sweeteners for weight loss, and has called for additional research on the long-term toxicity of low- and no-calorie sweeteners, the study said.

“Through their work, the investigators have shone a light on the safety of sugar substitutes. There is more to learn,” Dr Tomey said.

“In the meantime, it is worth remembering that sugar substitutes are no substitute for a sincere commitment to the several elements of a healthy diet and lifestyle.” CNN