Understanding UK Sweetener Regulation
All sweeteners permitted for use in the UK undergo a rigorous and ongoing safety assessment by regulatory bodies, including the UK Food Standards Agency (FSA) and previously, the European Food Safety Authority (EFSA). This process establishes an Acceptable Daily Intake (ADI) for each sweetener, representing the maximum amount that can be consumed daily over a lifetime without posing a health risk. The ADI is calculated with a generous safety margin, meaning most people are unlikely to exceed it through normal consumption habits.
Recent guidance from the Scientific Advisory Committee on Nutrition (SACN) specifically advises against giving sweetened drinks to young children to prevent them from developing a preference for sweet tastes. While SACN notes that sweeteners can help older children and adults reduce sugar intake, they are not considered essential for healthy weight management. This highlights the expert consensus that while approved sweeteners are safe within regulated limits, a broader dietary focus on reducing overall sweetness is recommended.
Spotlight on Popular Sweeteners
Stevia (E960)
Derived from the leaves of the Stevia rebaudiana plant, stevia is a popular natural-source sweetener. In the UK, only highly purified steviol glycoside extracts (known by the E-number E960) are approved for use, not the raw leaf. Stevia is calorie-free and does not impact blood sugar levels, making it suitable for people with diabetes. While generally considered safe, some people report a liquorice-like or bitter aftertaste. Some animal studies have also raised questions about its impact on gut microbiota, but human evidence remains inconclusive.
Erythritol (E968)
Erythritol is a sugar alcohol found naturally in some fruits, but commercially produced via corn fermentation. It is often used as a bulking agent alongside high-intensity sweeteners like stevia. It is zero-calorie and does not raise blood sugar. However, high doses can cause digestive issues like bloating and diarrhoea. A key concern arose from a 2023 study linking high circulating levels of erythritol to an increased risk of heart attack and stroke, particularly in individuals with pre-existing cardiovascular risk factors. While regulatory status has not changed, these findings prompted caution from some health experts, suggesting those at risk might prefer to avoid high consumption.
Sucralose (E955)
This artificial sweetener is derived from sucrose but is about 600 times sweeter. It is widely used and is stable for baking. Approved in the UK and over 80 other countries, including the USA. A 2024 review, however, cited recent research suggesting potential concerns regarding gut microbiome disruption, systemic inflammation, and toxicity when heated to high temperatures (above 119°C), though the evidence is described as mixed and more research is needed. These findings contrast with older, manufacturer-funded studies that affirm its safety.
Aspartame (E951)
One of the most studied artificial sweeteners, aspartame is widely used in diet products. Its safety has been a topic of debate for decades. The World Health Organization's cancer agency (IARC) classified aspartame as 'possibly carcinogenic to humans' (Group 2B) in 2023, based on 'limited evidence'. This is the same category as aloe vera extract and pickled vegetables. Crucially, the WHO's food additives committee (JECFA) simultaneously reaffirmed the existing Acceptable Daily Intake (ADI) of 40mg/kg of body weight, concluding the risk from normal consumption is low. In the UK, products containing aspartame must carry a warning for those with the rare genetic condition phenylketonuria (PKU), who cannot metabolise phenylalanine.
Comparison Table: Common UK Sweeteners
| Feature | Stevia (E960) | Erythritol (E968) | Sucralose (E955) | Aspartame (E951) |
|---|---|---|---|---|
| Source | Natural (plant leaf) | Natural (fruit/veg) & industrial | Artificial (chlorinated sucrose) | Artificial (amino acids) |
| Calories | Zero | Zero (less laxative than other polyols) | Zero | Low/Negligible |
| UK Regulatory Status | Approved within ADI | Approved within ADI (Recent concerns noted) | Approved within ADI (Recent concerns noted) | Approved within ADI (IARC Group 2B noted) |
| Taste Profile | Very sweet, can have aftertaste | Sugar-like, mild aftertaste | Sugar-like, no aftertaste | Sugar-like, loses sweetness when heated |
| Best For | Cold drinks, table-top | Table-top, baking (bulk) | Baking, drinks | Drinks, chewing gum |
| Noted Concerns | Potential gut effects (inconclusive) | Cardiovascular risk (high doses), digestive issues | Gut health, heated toxicity | PKU, 'possibly carcinogenic' label |
Making the Safest Choice for You
Determining the 'safest' sweetener depends on your individual health profile and dietary habits. All sweeteners approved for use in the UK have passed rigorous safety tests for consumption within the ADI. For those who prefer naturally sourced options and have no issues with its aftertaste, purified stevia extract is a very well-researched, zero-calorie choice. For those concerned about the recent erythritol study, especially those with existing heart conditions, it may be prudent to minimise intake until more is known. Aspartame remains a contentious topic, but regulatory bodies maintain that normal consumption is safe, with a specific risk only for individuals with PKU.
Ultimately, a balanced and varied diet is the cornerstone of good health, and relying heavily on any single sweetener or processed food is not advisable. The best approach is to reduce your overall preference for sweet tastes. The National Health Service (NHS) offers extensive guidance on reducing sugar intake and overall nutrition, which can be found here: https://www.nhs.uk/live-well/eat-well/food-types/are-sweeteners-safe/.
Conclusion: Navigating Sweetness Wisely
The question of which is the safest sweetener in the UK does not have a single, definitive answer but depends on weighing different factors. UK regulatory bodies, like the FSA, approve and monitor sweeteners, setting ADI levels considered safe for lifelong, moderate consumption. However, emerging research, such as that linking high erythritol intake to cardiovascular risk and ongoing debate over aspartame, encourages caution and vigilance. For most, the safest strategy is not about choosing one 'perfect' sweetener but about moderation, a balanced diet, and reducing the overall dependency on sweet tastes, whether from sugar or alternatives.
