Artificial Sweeteners and Erythritol: What the Evidence Says

TL;DR: Artificial sweeteners and sugar alcohols like erythritol let you have something sweet without the blood sugar rise that comes from sugar, which is why so many metabolically-minded people use them. The scary 2023 headline that erythritol causes blood clots came from studies that measured erythritol in the blood, and your body makes erythritol from glucose on its own, so a high level may be a sign of an underlying metabolic problem rather than proof the sweetener you ate caused harm. When these sweeteners replace sugar, the best trials show they modestly help with weight and blood sugar. The reasonable read in 2026 is to use them as a bridge off sugar, go easy on very large daily amounts of erythritol or xylitol if you already carry heart risk, and treat plain water as the ideal.

If you use stevia in your coffee, bake with erythritol, or drink sparkling water sweetened with monk fruit, and then a headline told you erythritol might cause blood clots, this page is for you. The fuller picture sits between two loud camps: the wellness message that these sweeteners are poison, and the industry message that they are proven harmless. What the evidence supports is more measured, and for someone trying to eat well, that nuance turns out to be useful.

What are the different kinds of sweeteners?

Sweeteners that replace sugar fall into three families, and telling them apart clears up most of the confusion.

The first family is the high-intensity sweeteners, used in tiny amounts because they taste hundreds of times sweeter than sugar. This group includes the synthetic ones, aspartame, sucralose, saccharin, and acesulfame-K, along with two plant-derived options, stevia (from the stevia leaf) and monk fruit. They carry close to no calories, and in careful testing none of them raise blood sugar in the moment, which is the reason people who watch their glucose favor them.

The second family is the sugar alcohols, also called polyols, which include erythritol, xylitol, sorbitol, and maltitol. These are bulkier, so they behave more like sugar in recipes, and they carry a few calories per gram. Erythritol is the odd one out in a good way: it is almost non-glycemic, and because the small intestine absorbs most of it and the kidneys clear it unchanged, it causes less gas than the others. Even so, a large single dose of erythritol (roughly 45 to 50 grams) can cause loose stool, and xylitol, sorbitol, and maltitol tend to cause bloating and a laxative effect at lower amounts.

The third family is allulose, a rare sugar in its own category. It carries almost no usable calories, does not raise blood sugar, and may lower the blood sugar rise from a meal eaten with it. A label-reading note: many monk fruit and stevia products are bulked out with erythritol or allulose, so the sweetener on the front of the package is often riding on a sugar alcohol you would want to know about.

Does erythritol cause blood clots or heart attacks?

This is the fear that sent people throwing out their sweeteners, so it deserves a careful answer. In 2023, a study in Nature Medicine reported that people with higher levels of erythritol in their blood had a higher three-year risk of heart attack, stroke, or death, with the risk in the top quarter running about 1.8 times higher in a US group and about 2.2 times higher in a European group.¹ The same team showed that erythritol made platelets, the cells that form clots, stickier in the lab and sped up clot formation in mice, and that a 30-gram dose raised blood erythritol far above the level tied to clotting for two to three days.

That sounds alarming until you see what the study did and did not measure, and this is where the story turns. It measured erythritol in the blood after an overnight fast, and your body makes erythritol on its own from glucose through a route called the pentose phosphate pathway. A 2017 study found that fasting blood erythritol was about 15 times higher in young adults who went on to gain belly fat and about 21 times higher in those with a rising HbA1c, the long-term blood sugar marker.⁴ So a high erythritol level may be a fingerprint of an underlying blood sugar problem rather than proof that the erythritol someone ate caused the harm. The studies never measured how much erythritol anyone consumed, the people in them were already being evaluated for heart disease, and the human dosing tests were small (as few as eight people) and used a large single dose rather than everyday use.

A companion study in 2024 found the same clotting pattern for xylitol, with a higher risk in the top group and a xylitol drink raising platelet stickiness.² A follow-up gave 20 healthy adults 30 grams of erythritol or the same amount of glucose, and only erythritol raised platelet reactivity.³ But 2025 added weight to the other side: a general-population study following about 4,000 older adults found that higher erythritol tracked with older age, diabetes, high blood pressure, and lower kidney function, and read it as a marker of poorer metabolic health rather than a cause.⁵

Where that leaves erythritol and xylitol is a question that is still open. The signal is biologically plausible, partly repeated as a risk marker, tangled up with the body's own production, and never tested against heart attacks or strokes in a randomized trial. That calls for humility and moderation, not alarm.

So should you avoid erythritol and xylitol?

For most people, the practical answer is moderation rather than avoidance. A stick of xylitol gum or a little erythritol in your coffee is nowhere near the doses in these studies. The place for caution is the daily keto baker who uses erythritol by the cup, or someone drinking liters of erythritol-sweetened drinks every day, and more so if that person already has a high risk of heart disease or clotting. Going easy on very large habitual loads while the endpoint data catch up is a sensible middle path. If you enjoy allulose or monk fruit, those do not carry the same clotting question, and plain or sparkling water carries none at all.

Do artificial sweeteners cause weight gain or diabetes?

Here the evidence pulls in two directions, and knowing which kind of study you are reading matters. In 2023 the World Health Organization suggested that non-sugar sweeteners not be used as a way to control weight or lower disease risk, a conditional recommendation built on low-certainty evidence.⁶ That recommendation rests mostly on large observational studies where people who use more sweeteners tend to weigh more and have more diabetes and heart disease over time.

The catch is that those studies cannot separate cause from effect. People who already carry extra weight or have diabetes are the ones who switch to diet drinks, which makes the sweetener look guilty for a problem that came first. When you look instead at randomized trials, where people are assigned to swap sugary drinks for sweetened ones, the picture reverses: a pooled analysis of 17 trials found that replacing sugary drinks with low- and no-calorie versions led to modest weight loss, about a kilogram, and better liver fat, similar to swapping in water.⁷ So when a sweetener replaces sugar, the controlled evidence points to a small benefit rather than harm.

The French NutriNet-Santé cohort is often cited on the worrying side. It reported that higher sweetener intake was associated with a slightly higher rate of cardiovascular disease and a somewhat higher rate of stroke, and in a separate report a modestly higher cancer rate.⁸⁹ Those associations are small, come from a single health-conscious group that recruited itself online, and carry the same cause-versus-effect problem, so they raise a question rather than settle one.

Does aspartame cause cancer?

In 2023 the International Agency for Research on Cancer placed aspartame in Group 2B, meaning "possibly carcinogenic," based on limited evidence for liver cancer in people and limited evidence in animals and lab studies.¹⁰ The headlines that followed were frightening, but the category is easy to misread. Group 2B is a statement about hazard, meaning could this cause cancer under some conditions, not about risk, meaning how likely is it at the amounts people consume. The same bucket holds things like aloe vera extract and pickled vegetables.

At the same meeting, the expert committee that sets safe-intake levels reviewed the same evidence and left the acceptable daily intake for aspartame unchanged. To pass that limit, a 70-kilogram adult would need to drink somewhere around 9 to 14 cans of diet soda every day, which is far beyond what almost anyone consumes. The measured takeaway is that there is a weak, limited-evidence flag for liver cancer, the safe-intake level did not move, and everyday intake sits nowhere near it.

Do sweeteners raise insulin or affect the gut?

Two smaller worries come up a lot. The first is whether the sweet taste alone triggers an insulin release even without sugar. The idea is plausible, since sweet-taste sensors line the gut, but the human evidence is weak and mixed, and controlled studies do not show a meaningful insulin rise from these sweeteners on their own. Erythritol and allulose do not raise insulin either, and allulose may even lower the blood sugar rise from a meal eaten alongside it, which is a point in its favor.¹²

The second worry is the gut microbiome. A 2022 trial gave 120 healthy adults one of four sweeteners for two weeks at doses below the safety limit and found that saccharin and sucralose modestly worsened blood sugar handling, while stevia and aspartame had little effect, and that the response varied a lot from person to person.¹¹ It is a credible signal, but a modest and short one measured over two weeks in healthy people, and it does not show that sweeteners cause diabetes. If you use a continuous glucose monitor, this is a place where you can test your own response and see whether a given sweetener nudges your numbers.

How Fishtown Medicine thinks about sweeteners in Philadelphia

We treat sweeteners as a tool with a specific job: helping people step off sugar without feeling deprived. For someone drinking regular soda or sweetening coffee with sugar, moving to a sweetener is almost certainly a step forward for weight and blood sugar, and we would rather someone make that swap than white-knuckle it and give up. At the same time, we frame sweeteners as a bridge rather than a destination, because the larger win is turning down the overall taste for sweet over time, which makes fruit taste sweeter and cravings quieter.

When we work with you, we connect the choice to your own numbers rather than to headlines. If you track glucose, we can see how your body answers a given sweetener; if you have heart or clotting risk, we can talk about going easy on very large erythritol and xylitol loads while the science matures. Whether you are in Fishtown or Cherry Hill, the aim is a way of eating you can keep, with sugar dialed down and the sweetener playing a small, supporting role.

Guidance from the Clinic

"I get asked about the erythritol headlines almost every week, usually by someone who has thrown out their sweeteners and feels a little guilty for having used them. What I want them to know is that the study everyone saw measured erythritol in the blood, and the body makes erythritol on its own when blood sugar runs high, so a high level was probably telling us about their metabolism, not about the packet in their coffee. For most people, using a sweetener to get off sugar is a good trade. If someone bakes with erythritol by the cup every day and already carries heart risk, I nudge them to ease up while we wait for better studies. Beyond that, I would rather we spend the worry on the sugar we are replacing."

Related at Fishtown Medicine

• Ultra-Processed Food: What It Does to Your Health - the larger dietary driver that sweeteners often sit inside
• Metabolic Health and Insulin Resistance - the system these choices feed into
• CGM for Non-Diabetics - test your own response to a sweetener
• Alcohol and Longevity - another "is it safe" question answered by the evidence
• High Uric Acid: More Than Just Gout - a marker driven by the sugar these replace
• TMAO: What the Gut-Heart Marker Tells You - the same blood-level-versus-diet puzzle from the same research group

Scientific References

1. Witkowski M, Nemet I, Alamri H, et al. "The artificial sweetener erythritol and cardiovascular event risk." Nature Medicine. 2023;29(3):710-718.
2. Witkowski M, Nemet I, Li XS, et al. "Xylitol is prothrombotic and associated with cardiovascular risk." European Heart Journal. 2024;45(27):2439-2452.
3. Witkowski M, Wilcox J, Province V, et al. "Ingestion of the non-nutritive sweetener erythritol, but not glucose, enhances platelet reactivity and thrombosis potential in healthy volunteers." Arteriosclerosis, Thrombosis, and Vascular Biology. 2024;44(9):2136-2141.
4. Hootman KC, Trezzi JP, Kraemer L, et al. "Erythritol is a pentose-phosphate pathway metabolite and associated with adiposity gain in young adults." Proceedings of the National Academy of Sciences. 2017;114(21):E4233-E4240.
5. Abushamat LA, Yu B, Hoogeveen RC, et al. "Erythritol, erythronate, and cardiovascular outcomes in older adults in the ARIC study." JACC: Advances. 2025;4(3):101605.
6. World Health Organization. "Use of Non-Sugar Sweeteners: WHO Guideline." Geneva: World Health Organization; 2023.
7. McGlynn ND, Khan TA, Wang L, et al. "Association of low- and no-calorie sweetened beverages as a replacement for sugar-sweetened beverages with body weight and cardiometabolic risk: a systematic review and meta-analysis." JAMA Network Open. 2022;5(3):e222092.
8. Debras C, Chazelas E, Sellem L, et al. "Artificial sweeteners and risk of cardiovascular diseases: results from the prospective NutriNet-Santé cohort." BMJ. 2022;378:e071204.
9. Debras C, Chazelas E, Srour B, et al. "Artificial sweeteners and cancer risk: results from the NutriNet-Santé population-based cohort study." PLoS Medicine. 2022;19(3):e1003950.
10. Riboli E, Beland FA, Lachenmeier DW, et al. "Carcinogenicity of aspartame, methyleugenol, and isoeugenol." The Lancet Oncology. 2023;24(8):848-850.
11. Suez J, Cohen Y, Valdés-Mas R, et al. "Personalized microbiome-driven effects of non-nutritive sweeteners on human glucose tolerance." Cell. 2022;185(18):3307-3328.
12. Braunstein CR, Noronha JC, Khan TA, et al. "Effect of fructose and its epimers on postprandial carbohydrate metabolism: a systematic review and meta-analysis." Clinical Nutrition. 2020;39(11):3308-3318.