Sweeteners: healthier than sugar?

Daniel Platteau

In short: the sweeteners authorised in Europe have been assessed, and at usual intakes, none has been shown to be dangerous to humans. But that does not make them "good for your health". WHO advises against relying on them to lose weight or prevent disease, because no long-term benefit has been shown, and large observational studies link them to more cardiovascular disease, without proving that they are to blame. Who is it for? Swapping a sugary soda for its "zero" version is still progress for a heavy soda drinker, but the goal remains water. Be careful with erythritol and xylitol (recent cardiovascular signals), and xylitol is strictly off-limits for dogs.

Updated on 16 October 2026.

This article is part of our series on food additives. For the basics (E numbers, acceptable daily intake, who decides), first read our introductory article. To find out whether you eat too much sugar, read our article on carbohydrates.

What is a sweetener?

A sweetener is an additive that gives a sweet taste without the sugar and its calories, or with very few. In Europe, there are two families.

Intense sweeteners are hundreds of times sweeter than sugar: a few milligrams are enough. They provide practically no calories.

Polyols (or "sugar alcohols") are less sweet than or as sweet as sugar and provide somewhat fewer calories: sorbitol (E420), maltitol (E965), xylitol (E967), erythritol (E968, practically calorie-free), etc. They are mainly found in "sugar-free" chewing gum and sweets, chocolate for diabetics and some "keto" products.

Two statements are mandatory on the label:

• "contains a source of phenylalanine" for aspartame, important for people with phenylketonuria, a rare genetic disease that requires avoiding it, including in some medicines (chewable tablets, syrups);
• "excessive consumption may produce laxative effects" for products rich in polyols: bloating and diarrhoea increase with the dose, especially with sorbitol and maltitol.

Is stevia more "natural"?

The Stevia rebaudiana plant is natural. The additive E960, on the other hand, is a purified extract of certain molecules from the leaf, obtained by an industrial process. Depending on the sub-category, these glycosides are extracted from the plant or obtained through enzymatic or fermentation processes. It has been assessed like the others. Natural does not mean safer, and artificial does not mean dangerous: what counts is the studies.

Are they safe? What the agencies say

An acceptable daily intake for each one

Each authorised sweetener has an acceptable daily intake (ADI): the amount that can be consumed every day, for a lifetime, without appreciable risk. It is generally set 100 times below the no-effect dose in animals.

EFSA is re-evaluating all sweeteners authorised before 2009. Since 2023, several opinions have been published, and several ADIs have been raised, not lowered:

• erythritol (2023): first ADI set, 0.5 g per kilo per day, based on the laxative effect;
• saccharin (2024): ADI raised from 5 to 9 mg/kg; EFSA ruled out a genotoxic risk, except for impurities from one particular manufacturing process;
• acesulfame K (2025): ADI raised from 9 to 15 mg/kg;
• sucralose (February 2026): ADI kept at 15 mg/kg, with a reservation about cooking at high temperatures (see below);
• cyclamate: opinion expected in 2027; sorbitol, xylitol and other polyols: under way.

In all these opinions, the actual exposure of Europeans, including the heaviest consumers, remains below the ADI.

Aspartame and cancer: hazard or risk?

In July 2023, the International Agency for Research on Cancer (IARC) classified aspartame as "possibly carcinogenic" (group 2B), on the basis of limited evidence, particularly for liver cancer. The same month, the WHO/FAO expert committee (JECFA) kept its ADI at 40 mg per kilo (WHO, 2023b).

This is not a contradiction: IARC says whether a substance could cause cancer under certain conditions (the hazard), JECFA says at what dose (the risk). Group 2B also includes aloe vera extract and Asian-style pickled vegetables. To exceed the ADI, a 70-kg adult would have to drink more than 9 to 14 cans of diet soda a day, with no other source of aspartame.

Do they help you lose weight?

This is the question that matters most, and the answer is nuanced.

WHO says no… for prevention

In May 2023, the World Health Organization published a recommendation: do not use non-sugar sweeteners to control body weight or reduce the risk of chronic disease (WHO, 2023a). Its arguments:

• in randomised trials, the effect on weight is small and does not last;
• in long-term observational studies, heavy consumers have more type 2 diabetes, cardiovascular disease and deaths.

Three important points:

• it is a conditional recommendation, based on low-certainty evidence;
• it does not apply to people with diabetes;
• it does not cover polyols such as xylitol or erythritol.

A European trial says yes… for keeping off lost weight

In October 2025, the European SWEET trial was published in Nature Metabolism (Pang et al., 2025). 341 overweight adults in Denmark, Spain, Greece and the Netherlands first lost weight on a two-month very-low-calorie diet. Then, for ten months, one group replaced sugary products with sweetened products and the other did not, with both groups keeping sugars below 10% of their calories.

The result after one year: the "sweeteners" group had kept off 1.6 kg more weight. There was no difference in cholesterol, blood sugar or blood pressure, nor in the children. The authors did not observe any harmful effect on the gut microbiota.

Level of evidence: a solid randomised trial, but a modest effect, and authors some of whom have received fees or funding from the sweetener or beverage industry. The project itself was funded by the European Union.

How can the two be reconciled?

The two results do not contradict each other. Replacing a sugary food with its sweetened version removes calories: in the short term, that helps. But drinking a zero soda does not make you slim, and many observational studies compare people who drink it because they are already overweight or diabetic. This is called reverse causation: the disease leads to the consumption, not the other way round. Other biases add to this, such as the rest of the diet or smoking, which statistics never fully correct.

Warning signals: what you should know

The French NutriNet-Santé studies

This large cohort has been following French volunteers since 2009. Two 2022 publications made headlines:

• among nearly 103,000 adults, the heaviest consumers of sweeteners had a slightly higher risk of cancer, of around 13%, especially for aspartame and acesulfame K (Debras et al., 2022a);
• in the same cohort, the heaviest consumers had a risk of cardiovascular disease about 9% higher; aspartame was mainly associated with strokes, acesulfame K and sucralose with coronary heart disease (Debras et al., 2022b).

These are associations: the authors took many factors into account (weight, diabetes, smoking, diet), but an observational study does not prove cause.

Erythritol and xylitol: polyols under watch

In 2023, a Cleveland Clinic team showed that heart patients with a high blood level of erythritol had about twice as many heart attacks, strokes or deaths over three years (Witkowski et al., 2023). In 2024, the same team gave 30 g of erythritol to 10 healthy volunteers (and 30 g of glucose to 10 others): blood erythritol levels rose more than 1,000-fold, and their platelets, the cells that form clots, became markedly more reactive (Witkowski et al., 2024).

Xylitol has followed the same path: a signal in 2024 in fragile patients, then, at the European Society of Cardiology congress in September 2026, an analysis of two large cohorts (Canadian and British, 17,710 people). In Canada, people with the highest xylitol levels had a 57% higher risk of a major cardiovascular event over six years (Futura, 2026).

The limitations are important: the body makes erythritol and xylitol itself, and a high blood level may reflect a disturbed metabolism rather than intake. The 30 g used in the trial is a large serving, found in some "keto" drinks or pastries. This work does not prove that erythritol causes heart attacks, but the signal is consistent and justifies caution in people at cardiovascular risk.

Microbiota, memory, immunotherapy

• Microbiota: in 2022, an Israeli trial in 120 adults showed that within two weeks, saccharin and sucralose changed the microbiota and the glucose response in some people, the effect varying from one individual to another (Suez et al., 2022). The longer SWEET trial found no harmful effect. The question remains open.
• Memory: in 2025, a Brazilian study of 12,772 adults followed for eight years observed 62% faster cognitive decline in the heaviest consumers, but only in those under 60 (Gonçalves et al., 2025). Observational, with diet measured only once at the start.
• Immunotherapy: in 2025, a Pittsburgh team showed that in 132 patients with melanoma or lung cancer, high sucralose consumption went hand in hand with a poorer response to immunotherapy. In mice, sucralose changes the microbiota, which then consumes the arginine that immune cells need (Morder et al., 2025). A result to be confirmed, but one worth flagging to patients being treated.

Cooking with sucralose: beware of heat

The German Federal Institute for Risk Assessment (BfR) recommends not heating sucralose above 120 °C: unwanted chlorinated compounds could form. EFSA repeated this reservation in 2026 for home baking and frying (EFSA FAF Panel, 2026). For oven cooking, a little sugar is better than a heated sweetener.

What to do in practice?

If you drink sugary sodas every day: switching to the zero version is real progress (less sugar, fewer cavities, fewer calories). But see it as a step towards water, sparkling water or herbal teas.

If you want to lose weight: sweeteners can help you stick to a diet, not replace it. What matters most is still the quantity and quality of what you eat.

If you have diabetes: intense sweeteners do not raise blood sugar and can be helpful. Talk to your doctor or dietitian about it.

If you are at high cardiovascular risk (past heart attack or stroke, diabetes, high blood pressure): avoid large doses of erythritol and xylitol ("keto" drinks and desserts, "zero calorie" powdered sugar based on erythritol). An occasional xylitol chewing gum is not comparable to 30 g in one go.

For children: no sweetened drinks on a daily basis. They keep up the taste for sweetness and do not replace water.

For cooking: do not heat sucralose in the oven or the pan.

If you are on immunotherapy for cancer: tell your oncologist about your consumption of products containing sucralose, and ask for advice.

What is pointless: tracking every milligram. A sweetened yoghurt or a coffee sweetened with stevia poses no demonstrated problem. It is large daily amounts, especially in drinks, that deserve thought.

Going further: why the studies contradict each other

Sweeteners are a textbook case of the difficulties of nutrition research.

Observational studies follow thousands of people for years. They are essential for spotting signals, but sweetener consumers are not like everyone else: they are more often overweight, diabetic or on a diet. Even with statistical adjustments, this bias never fully disappears.

Randomised trials assign at random who consumes what: they remove this bias, but they are short (from a few weeks to a year) and cannot measure cancer or heart attacks, which take years to appear.

Animal and laboratory studies show plausible mechanisms (platelets, microbiota, arginine), but often at high doses.

We talk about "sweeteners" in the plural, whereas aspartame, sucralose, stevia and erythritol are very different molecules, which neither behave the same way in the body nor have the same possible effects. Sweeping general conclusions, positive or negative, are therefore fragile.

There are interests on both sides: the beverage and sweetener industry funds part of the research, and alarming studies get more press coverage. Always look at who funds a study, how many people were followed, and whether it is an association or a trial.

The most honest summary today: sweeteners are an acceptable stopgap for replacing sugar, not a health food. The long-term goal is still to get used to a less sweet taste.

Next article in the series: nitrites. Already published: titanium dioxide (E171).

Test yourself

Disclaimer

This article is a summary of information. It does not replace the advice of a doctor or dietitian, especially in case of diabetes, cardiovascular disease, phenylketonuria or cancer treatment.

Sources

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Debras, C., Chazelas, E., Sellem, L., et al. (2022b). Artificial sweeteners and risk of cardiovascular diseases: Results from the prospective NutriNet-Santé cohort. BMJ, 378, e071204. https://doi.org/10.1136/bmj-2022-071204

EFSA Panel on Food Additives and Flavourings. (2024). Re-evaluation of saccharin and its sodium, potassium and calcium salts (E 954) as food additives. EFSA Journal, 22(11), e9044. https://doi.org/10.2903/j.efsa.2024.9044

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Futura. (2026, September 9). « Un signal préoccupant » : cet édulcorant très courant est associé à un risque cardiovasculaire jusqu'à 57 % plus élevé (in French). Futura Santé. https://www.futura-sciences.com/sante/actualites/maladies-cardiovasculaires-signal-preoccupant-cet-edulcorant-tres-courant-associe-risque-cardiovasculaire-jusqua-57-plus-eleve-137622/

Gonçalves, N. G., Martinez-Steele, E., Lotufo, P. A., Bensenor, I., Goulart, A. C., Barreto, S. M., Giatti, L., Perim de Faria, C., Bisi Molina, M. D. C., Caramelli, P., Marchioni, D. M., & Suemoto, C. K. (2025). Association between consumption of low- and no-calorie artificial sweeteners and cognitive decline: An 8-year prospective study. Neurology, 105(7), e214023. https://doi.org/10.1212/WNL.0000000000214023

Morder, K. M., Nguyen, M., Wilfahrt, D. N., Dahmani, Z. L., Burr, A. B. P., Xie, B., … Overacre-Delgoffe, A. E. (2025). Sucralose consumption ablates cancer immunotherapy response through microbiome disruption. Cancer Discovery. https://doi.org/10.1158/2159-8290.CD-25-0247

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