Sorbitol
A naturally occurring sugar alcohol used as a low-calorie sweetener and moisture-retaining agent in sugar-free and reduced-sugar foods.
In amounts above roughly 50g a day, sorbitol draws water into the large intestine, causing bloating, cramps and diarrhoea. People with irritable bowel syndrome can react at much lower amounts.
What is it?
Sorbitol is a sugar alcohol (polyol) that occurs naturally in some fruits, including apples, pears, plums and cherries. It is commercially produced by hydrogenating glucose derived from corn or wheat starch. E420 covers two forms: sorbitol (E420i) and sorbitol syrup (E420ii), which is a solution of sorbitol with related hydrogenated carbohydrates.
What does it do?
Sorbitol provides sweetness at about 60% of the intensity of sucrose while delivering fewer calories (approximately 2.4 kcal/g versus 4 kcal/g for sugar). Because it is only partially absorbed in the small intestine, less glucose enters the bloodstream, giving it a low glycaemic index. It also retains moisture well, so it keeps foods soft and extends shelf life. In confectionery it prevents crystallisation and adds bulk where sugar has been removed.
Where you will see it
Found in sugar-free chewing gum and mints, diabetic chocolate and sweets, reduced-sugar baked goods, jam and marmalade, ice cream and frozen desserts, dried fruit coatings, medicines and cough syrups, mouthwash and toothpaste. On a label it appears as Sorbitol, Sorbitol syrup, or E420.
What the science says
Laxative effect above a daily threshold
Sorbitol is incompletely absorbed in the small intestine. The unabsorbed fraction passes into the large intestine, where it draws water by osmosis and is fermented by gut bacteria, producing gas. At intakes above roughly 50g a day this reliably causes bloating, cramps, loose stools and diarrhoea. UK food law requires a warning label on any food where added polyols exceed 10% of the product.
A total of 25g of sorbitol daily in two doses caused no laxative effect in 86 subjects, while quantities above 50g daily produced diarrhoea.
EU and UK legislation requires any food product containing more than 10% added polyols, including sorbitol, to carry the statement: 'Excessive consumption may have laxative effects'.
IBS and gut sensitivity
People with irritable bowel syndrome are often sensitive to a group of poorly absorbed short-chain carbohydrates known as FODMAPs. Sorbitol is classified as a FODMAP. Clinical dietetic practice routinely restricts sorbitol intake for people following a low-FODMAP diet, and symptom thresholds for IBS patients can be far lower than the 50g figure in the general population.
Dietary restriction of FODMAPs, including polyols such as sorbitol, significantly reduced IBS symptom scores in randomised trials compared with a control diet.
Sorbitol is listed as a high-FODMAP food requiring restriction in low-FODMAP dietary guidance for IBS management.
Blood glucose and dental effects
Because sorbitol raises blood glucose more slowly and to a lesser degree than sucrose, it has been used in foods marketed to people with diabetes. Its use as a sweetener in sugar-free gum is also backed by evidence that it does not contribute to tooth decay, and the EU permits dental health claims for polyol-sweetened products. However, it still provides calories and should not be treated as calorie-free.
Sugar alcohols including sorbitol have a lower glycaemic index than sucrose and do not promote dental caries.
Where it stands with the regulators
Who should be careful
People with irritable bowel syndrome following a low-FODMAP diet should treat sorbitol as a high-FODMAP ingredient and limit or avoid it. People with fructose malabsorption are often also sensitive to sorbitol. People with diabetes should be aware that sorbitol still provides calories even though it has a low glycaemic index. Look for Sorbitol, Sorbitol syrup or E420 on the label.
The honest read
The laxative effect of sorbitol is real, dose-dependent, and well-established in clinical literature. The 50g daily threshold for the general population is a reasonable guide, but people with IBS or gut sensitivity can react at much lower amounts. The mandatory warning label on high-polyol foods exists because the effect is predictable enough to require statutory disclosure. The dental and glycaemic properties are genuinely supported by regulatory-level evidence. There are no signals of carcinogenicity, endocrine disruption, or organ toxicity at food-use levels, and regulators have not set a toxicological ADI. The practical concern is gastrointestinal, not systemic.
Related additives
Common questions
Is E420 banned in the UK?
No. Sorbitol (E420) is approved for use in the UK and EU under assimilated EU Regulation 1333/2008. It has been on the EU and UK positive lists for many years with no bans or restrictions imposed.
Why do some sugar-free products carry a laxative warning?
UK and EU law requires any food containing more than 10% added polyols, including sorbitol, to state 'Excessive consumption may have laxative effects' on the label. The warning reflects the fact that sorbitol is only partially absorbed and can cause bloating, cramps and diarrhoea at high intake.
What foods contain E420?
Sugar-free chewing gum and mints, diabetic chocolate and sweets, reduced-sugar baked goods, dried fruits, jams and marmalade, frozen desserts, and some cough syrups and medicines. It appears as Sorbitol, Sorbitol syrup or E420 on the ingredients list.
Is E420 vegan?
Yes. Commercial sorbitol is produced by hydrogenating glucose from plant starch, typically corn or wheat, and involves no animal-derived ingredients or processing.
Sources
- UK FSA: Approved additives and E numbers
- Assimilated EU Regulation 1333/2008 on food additives (UK retained law)
- EFSA NDA Panel: Scientific opinion on the substantiation of health claims related to polyols and dental health (2011)
- Gibson PR & Shepherd SJ: Evidence-based dietary management of functional gastrointestinal symptoms, Journal of Gastroenterology and Hepatology
- Monash University: The Low FODMAP Diet
- British Dietetic Association (BDA): IBS and diet fact sheet
- Safety of sugar alcohols on human health, International Journal of Food Science and Technology, Oxford Academic (2024 review)
Aaron Keen is the founder of NutraSafe. He researches and writes every additive entry himself, from the primary sources. About the research →
This is a guide, not medical advice. If an additive affects you, speak to your GP or a dietitian.
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