Explainer: what are E numbers and should you avoid them in your diet?

The “E numbers” in the ingredients list of your packaged foods replace the chemical or common name of particular food additives. These are used to enhance the colour, flavour, texture or prevent food from spoiling.

Food additives have been used for centuries. The ancient Romans would use spices such as saffron to give foods a rich yellow colour. Salt and vinegar were used to preserve meats and vegetables for long voyages.

In the 1960s, regulators decided to make a standardised list of these additives. In Europe, these are referred to as E numbers (the E stands for Europe). In Australia, we just use their code number.

So, vitamin C would be called E300 in Europe. In Australia, it can be found on labels with the code number 300, such as “food acid 300”, “ascorbic acid (300)” or “vitamin C (300)”.

What do the numbers mean?

100 to 199: Food colouring. Saffron is “food colour 164” in Australia (or E164 in Europe). Other spices commonly used to add colour to foods include turmeric (E100) and paprika (E160c).

200 to 299: Preservatives. These prevent the growth of microbes in food that might make us sick. E220, for example, is sulphur dioxide, a preservative commonly used in wine to stop acetic acid bacteria from turning the wine into vinegar.

300 to 399: Antioxidants. Vitamin C (E300) falls into this category.

400 to 499: Thickeners, emulsifiers and stabilisers. Thickeners are commonly used in soups or sauces. Emulsifiers help keep oily substances and watery substances mixed, such as mayonnaise. Without emulsifiers, the oily and watery part can separate, as seen with vinaigrettes.

500 to 599: Acidity regulators and anti-caking agents. Sodium bicarbonate (E500), commonly known as baking soda or bicarb soda, regulates acidity.

600 to 699: Flavour enhancers, including monosodium glutamate (E621) or MSG.

700 to 999: Sweeteners, foaming agents and the gases used to package foods, such as nitrogen gas (E941). This is used in most potato chip packaging, as it stops them from oxidising.

Many E numbers are naturally occurring substances, such as vitamin B1 (E101) and even oxygen (E948).

Regulation of E numbers

E number restrictions vary between countries, depending on how the local regulatory authorities interpret the product’s toxicity results. Toxicity is the ability for a substance to cause damage, which is often related to how much of the substance is eaten.

Everything is toxic in a high enough dose. Even caffeine is toxic if you have enough of it. But most people don’t consume anywhere near a toxic dose, which would be more than 100 cups of coffee.

Some E number additives are banned elsewhere in the world but not in Australia. Let’s look at what the science says about the key culprits.

Amaranth (E123)

Amaranth (E123) is used to give a dark-red colour to foods. It is permitted for use in foods at concentrations of up to 30mg/kg in Australia and the European Union but is banned in the United States due to concerns it causes cancer.

In 1971, a Russian study linked the dye to cancer in rats. There was considerable criticism of the methodology of the study and the US Food and Drug Administration (FDA) undertook several subsequent studies.

The FDA found little evidence amaranth was harmful. In one study, female rats given high doses did have an increase in malignant tumours. However, the dose was so high a human would have to drink 7,500 cans of soft drink a day to reach it.

However, following significant public outcry, in 1976 the FDA banned this food colouring.

Food manufacturers in the United States could apply to have it retested, but that’s an expensive process. E123 has been replaced by another red colouring agent, E129, one of the “Southampton six”.

The ‘Southampton six’

In 2007, a UK study found a link between mixtures of food colouring and increased hyperactivity in children. Two colouring mixtures were used: Mix A (containing E102, E110, E122 and E124) and Mix B (containing E104, E110, E122, E129).

The study measured hyperactivity by parent-teacher questionnaires, computer tests and having psychology students directly observe children in a classroom.

Both mixes appeared to be associated with hyperactivity in children aged eight to nine years, but only Mix A was linked to hyperactivity in three-year-olds.

The evidence behind the Southampton six is mixed.Peer/Flickr, CC BY-NC-SA

Following public outrage, a “voluntary ban” was implemented in 2009. This means the colours can be added to foods in the United Kingdom and European Union, but they must carry a warning that they “may have adverse effect on activity and attention in children”.

While food manufacturers can continue to use them, the bad publicity following their continued use prompted many to find alternatives.

No warnings are required for these additives in Australia, following investigation by the food regulator, Food Standards Australia New Zealand (FSANZ).

Tartrazine (E102)

FSANZ reviewed tartrazine (E102) – one of the Southampton six – in 2014 and confirmed it was non-toxic and safe for consumption. FSANZ did admit uncertainty, though, about its effects on hypersensitivity.

In the US and EU, products containing tartrazine must carry a warning that they may cause allergic-type reactions in susceptible people.

One study found that tartrazine led to an allergic reaction in about a quarter of people with allergies.

A more recent review found that avoiding tartrazine can help control asthma – but only for people who are sensitive to it.

It has been suggested tartrazine might contribute to hyperactivity, but only in those children who are sensitive to it.

There is also some evidence to suggest that certain children with ADHD may be genetically sensitive to food colours. Consuming excessive food colours may therefore make their symptoms worse.

Conflicting results

The Southhampton study used a mixture of food colours and the preservative sodium benzoate (E211). However, it wasn’t clear which individual food colour or preservative had an effect.

The group’s earlier (2004) study tested a mixture of food colours with sodium benzoate and found an increase in parent-reported hyperactivity.

However, a recent study of Chinese children found no effect from either food colouring or sodium benzoate when given separately.

A follow up to the 2007 Southhampton study has suggested genetic differences may make some people sensitive to the effects of food additives. This may explain the inconsistent results seen among studies.

Some people may have sensitivities, which means they would benefit from carefully reading food labels to avoid certain E numbers, but most people will be able to consume these additives without any side effects.

Melinda Coughlan receives funding from the National Health & Medical Research Council of Australia (NHMRC) and the Juvenile Diabetes Research Foundation (JDRF).

Matthew Snelson receives an Australian Postgraduate Award (APA), funded by the Australian Government Department of Education and Training.