What Food Additives Should You Avoid?

First: Most Additives Are Fine

Before diving into the ones that raise questions, it is important to set the context. There are over 300 approved food additives in the UK. The vast majority are well-established, thoroughly studied, and cause no issues for the overwhelming majority of people.

Many additives are substances you would recognise from your own kitchen:

• E300 — Ascorbic acid (vitamin C)
• E330 — Citric acid (found naturally in lemons)
• E440 — Pectin (used to set jam)
• E500 — Sodium bicarbonate (baking soda)
• E160a — Beta-carotene (gives carrots their colour)
• E322 — Lecithin (found naturally in egg yolks and soybeans)

The E-number system itself is simply a way of categorising approved additives. Having an E-number does not make something dangerous — it means it has been assessed and approved for use.

The Southampton Six: Artificial Colours

These are the additives with the strongest evidence of concern, specifically in relation to children’s behaviour. A 2007 study by the University of Southampton, commissioned by the FSA, found that mixtures of these six artificial food colours, combined with sodium benzoate (E211), were associated with increased hyperactivity in some children.

Following the study, the FSA advised that manufacturers should voluntarily remove these colours from their products. Many major UK brands have done so, replacing them with natural alternatives like beetroot juice, paprika extract, and turmeric. Products that still contain these colours must carry a warning: “May have an adverse effect on activity and attention in children.”

For more on this topic, see our dedicated guide on food additives and children’s behaviour.

Preservatives That Attract Questions

Sodium nitrite (E250) and sodium nitrate (E252)

These are used in processed meats — bacon, ham, salami, sausages — to prevent the growth of Clostridium botulinum (the bacteria that causes botulism) and to maintain the pink colour of cured meat.

The concern is that nitrites can react with amino acids in meat during high-temperature cooking (such as frying bacon) to form nitrosamines, which are classified as probable carcinogens by the International Agency for Research on Cancer (IARC). The World Health Organisation classifies processed meat as a Group 1 carcinogen, meaning there is sufficient evidence that it causes cancer — though the actual increase in risk from moderate consumption is small.

The FSA regulates the amount of nitrite permitted in food, and UK manufacturers must stay within these limits. Some brands now offer “nitrite-free” bacon and ham, though these products sometimes use celery extract (which naturally contains nitrates) instead.

Sodium benzoate (E211)

A preservative commonly found in soft drinks, sauces, and pickled foods. On its own, it is considered safe at permitted levels. However, when combined with ascorbic acid (vitamin C, E300) in acidic drinks, it can form small amounts of benzene, a known carcinogen. UK manufacturers have largely reformulated to avoid this combination, and the FSA has stated that the levels found in UK soft drinks are well below safety thresholds.

E211 was also one of the additives used in the Southampton study alongside the six artificial colours, though its individual contribution to hyperactivity is less clear.

Sulphites (E220–E228)

Sulphites are preservatives used in wine, dried fruit, some processed meats, and certain soft drinks. They are one of the 14 major allergens that must be declared on UK food labels. Approximately 5–10% of people with asthma are sensitive to sulphites, and reactions can range from mild wheezing to severe breathing difficulties.

If you know you are sulphite-sensitive, checking labels is essential. The most common sulphite additives are sulphur dioxide (E220), sodium metabisulphite (E223), and potassium metabisulphite (E224).

Artificial Sweeteners: A Nuanced Picture

Artificial sweeteners are among the most debated food additives. Here is what the evidence says about the main ones used in UK food.

Aspartame (E951)

Used in diet drinks, sugar-free gum, and low-calorie yoghurts. EFSA conducted a comprehensive review in 2013 and confirmed it as safe at the acceptable daily intake (ADI) of 40mg per kilogram of body weight. In 2023, the WHO’s International Agency for Research on Cancer (IARC) classified it as “possibly carcinogenic” (Group 2B), but the Joint FAO/WHO Expert Committee on Food Additives (JECFA) simultaneously reaffirmed the existing ADI, concluding the evidence was not strong enough to change the safety threshold.

People with phenylketonuria (PKU) must avoid aspartame, which is why products containing it carry a “contains a source of phenylalanine” warning.

Acesulfame K (E950) and Sucralose (E955)

Both are widely used in UK food and drink. They are considered safe by the FSA and EFSA at current permitted levels. Some emerging research has explored potential effects on gut microbiome composition, but this remains in early stages and has not changed regulatory positions.

Saccharin (E954)

One of the oldest artificial sweeteners. Earlier studies in rats suggested a link to bladder cancer, but subsequent research showed this mechanism was specific to rats and not applicable to humans. It is considered safe by all major regulatory bodies.

Other Additives That Attract Attention

Titanium dioxide (E171)

A white colouring agent used in sweets, chewing gum, and some sauces. The EU banned E171 in food from August 2022 based on a 2021 EFSA opinion that it could no longer be considered safe, citing concerns about genotoxicity (potential to damage DNA). The UK has not followed suit and is conducting its own review through the FSA’s Committee on Toxicity. As of early 2026, E171 remains permitted in UK food.

Monosodium glutamate / MSG (E621)

A flavour enhancer found in crisps, stock cubes, ready meals, and Chinese food. Despite persistent claims of “Chinese restaurant syndrome,” large-scale scientific reviews have not found a consistent link between MSG and reported symptoms like headaches and flushing when consumed at normal dietary levels. EFSA set an ADI of 30mg/kg body weight in 2017. MSG is considered safe by the FSA.

Carrageenan (E407)

A thickener extracted from red seaweed, used in ice cream, plant milks, and desserts. Some animal studies have raised concerns about gut inflammation, but these typically used degraded carrageenan (poligeenan), which is a different substance from the food-grade carrageenan used in products. EFSA reviewed carrageenan in 2018 and maintained its approval, though it recommended reducing the ADI.

BHA (E320) and BHT (E321)

Antioxidant preservatives used in fats, oils, and some cereals to prevent rancidity. Both have been subject to debate, with some animal studies suggesting potential concerns at high doses. EFSA has reviewed both and maintains their approval within specified limits. Their use in UK food has declined as many manufacturers have switched to alternative antioxidants.

Practical Shopping Tips

Rather than memorising lists of E-numbers, here are practical strategies for managing your additive intake.

• Read the ingredient list, not just the nutrition label — The ingredients tell you what is actually in the food. If you do not recognise several items, it is worth investigating.
• Shorter ingredient lists are usually simpler — Products with fewer ingredients tend to be less processed and contain fewer additives.
• Use a scanner app for speed — Rather than Googling every E-number in the shop, use an app like NutraSafe to scan barcodes and get instant additive breakdowns.
• Compare similar products — Two brands of the same food can have very different additive profiles. Scanning both takes seconds.
• Watch “health” products — Low-fat, sugar-free, and high-protein products often contain more additives than their standard counterparts to compensate for removed ingredients.
• Check for the Southampton Six warning — If you are buying food for children, look for the mandatory warning label on products containing the six artificial colours linked to hyperactivity.
• Cook from scratch when practical — The most effective way to reduce additive intake is to cook with whole ingredients. This does not have to mean every meal — even swapping a few ready meals per week for home-cooked food makes a difference.

Frequently Asked Questions

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