The hidden side of clinical trials

Watch the AllTrials TEDx talk on YouTube

Learn more

Evidence matters to the public

Join us on 1st November at Parliament to make the case

Learn more

Plant Science Panel

Insecticides, biofuels, GMOs …

Learn more

'The Ugly Truth'

by Tracey Brown, director of Sense About Science

Learn more

Food additives

Following many enquiries from journalists, researchers and the general public about food additives and health, we asked some of the specialists who help us on these subjects to provide some straightforward answers about the science behind food preservation, the meaning and reasons for E-numbers in food and drink, what scientists say about possible adverse health effects of specific additives, and how they are tested and regulated for public safety.

Food additives online resource

This resource is designed for journalists, commentators and anyone else interested in public discussion about these subjects. Responses to the frequent questions are listed below along with links and further resources.

What are food additives?

Additives are ingredients used in the preparation of processed foods. Some of these are extracted from naturally occurring materials, others are manufactured by the chemical industry. But like every other component of food, all additives are chemicals. Preservatives, colours and flavours are the best known additives but antioxidants, emulsifiers, stabilisers, gelling agents, thickeners and sweeteners are also commonly used. The most important additives are preservatives, without which food would quickly go bad. John Emsley, chemical scientist

“Many agents that are essential for commercial food preparation and storage have their analogues in the kitchen”

Paul Illing, toxicologist

What is an E-number?

Since 1986, food additives — colours, preservatives, antioxidants, stabilisers, gelling agents, thickeners, etc. — have been identified in food labels, either by name or by E-number. An E-number says that it has been approved for its intended use across the European Union. Approval depends on scientific testing and monitoring and is reviewed in the light of new scientific information. Additives have been around for centuries. Nitrites and nitrates (E249-252) have been used as curing agents. Baking powder (bicarbonate of soda [sodium hydrogen carbonate], cream of tartar [potassium hydrogen tartrate, monopotassium tartrate, E336] and starch) is a 19th century additive. Pickling is an ancient method of preservation that uses vinegar (acetic acid, E260) to prevent microbial spoilage.

Many agents that are essential for commercial food preparation and storage have their analogues in the kitchen. Caramel (E150a), a colouring agent, can be made at home by heating sugar. Gelling agents include pectin (methylated ester of galacturonic acid, E440) for jams. Preservatives include benzoic acid (E210), present in high quantities in cranberries. Some additives are clearly beneficial: in 1941 calcium was added to flour to prevent rickets; and anti-oxidants (necessary to prevent the fats in all prepared foods involving meat or pastry from going rancid) include ascorbic acid (vitamin C, E300) and the tocopherols (vitamin E, E306-309). Paul Illing, toxicologist

“It is notoriously difficult to assess whether additives really affect behaviour”

Judy More, paediatric dietician

Benzoic acid and food colorants

Benzoic acid is a natural chemical which is found in cranberries, bilberries, plums, cloves, and cinnamon, some of which are said to be particularly beneficial on health grounds. It is added to processed foods to protect them. It does this by preventing the growth of microbes, and in particular pathogenic moulds and fungi. Even if the food colorants which were part of the new FSA study were removed from foods I would not like to see benzoic acid removed unless an equally effective chemical were to replace it. If it was simply removed then I am sure there would be an increase in cases of food poisoning among young children that might well be more harmful to them than a possible reduction in their bad behaviour. John Emsley, chemical scientist

Food additives and children

There is an unclear link between food additives and hyperactivity. Whilst many parents report artificial colours and preservatives to trigger hyperactivity in their children, randomised controlled trials have failed to demonstrate a link. A recent study carried out by Southampton University suggested that some artificial food colours, together with the preservative sodium benzoate, could have a negative effect on some children’s behaviour. Whilst it is not clear which individual colours are to blame, the Food Standards Agency has suggested that parents of children showing signs of hyperactivity try eliminating the cocktail of colours investigated in this study - Sunset yellow (E110), Quinoline yellow (E104), Carmoisine (E122), Allura red (E129), Tartrazine (E102) and Ponceau 4R (E124)—to see it this leads to any benefits. It is however important to remember that many other factors are likely to be involved. Sara Stanner, senior nutrition scientist

Some children may be susceptible to some additives and other children to different things. It is notoriously difficult to assess whether additives really affect behaviour because there are so many other confounding factors that would have to be taken into account: things like low blood sugar, tiredness and whether they had been subject to psychological stress in the time frame of the study. Asking parents to assess their children can additionally introduce the element of bias — all these factors make it very hard to look at the effect of particular additives in isolation. Judy More, paediatric dietician

“With our increasingly complex food supply food additives play a vital role. Never before has the range and choice of foods been so wide either in supermarkets, specialist food shops or when eating out.”

Nigel Denby, nutrition consultant

How is the use of food additives controlled?

There are EU-wide regulations that list the additives which have been tested and shown to be safe for use in food. These regulations list the foods in which each permitted additive is allowed, and its level of use. The list is first provided by the European Commission but the final decision is taken jointly by elected representatives of all EU member states and members of the European Parliament. Testing for levels of permitted additives considers differences in body weight and the needs of vulnerable members of the population e.g. the ill, elderly. An EU approved additive is denoted an ‘E’ number and can be referred to on packs as this or by its full name.

Safety tests

Safety tests include animals being given the additive, mixed with their diet, at much higher concentrations than will occur in human food. The tests are designed to give information on any possible effects from short-term or long-term exposure to the proposed additive, including whether it may have any potential to cause cancer, affect reproductive processes or the development of the embryo or fetus if consumed by a pregnant woman. Tests are also carried out to assess its ability to interfere with genetic material in the body, which could lead to the development of cancer or adverse effects in future generations.

The results of the safety tests are assessed by independent experts (now European Food Safety Authority, EFSA) and used to calculate the Acceptable Daily Intake (ADI) for humans. The ADI is defined as: “an estimate of the amount of the food additive, expressed on a body weight basis, that can be ingested daily over a lifetime without appreciable health risk” and is expressed on a milligram per kilogram bodyweight per day basis (mg/kg bw/day). The ADI concept is used extensively by regulatory bodies throughout the world, such as the US Food and Drugs Administration (FDA), the World Health Organisation (WHO) and the European Community (EC) to confirm that ingestion of all additives remains within safe levels. It applies to people of all ages, children as well as adults. After approval, additives are subject to continuous monitoring and review. See

E stands for Europe

“An E-number says that it has been approved for its intended use across the European Union.”

Paul Illing, toxicologist

Can additives lead to allergies/intolerances?

Additives cannot cause allergies but at high doses they can cause reactions or intolerances in some sensitive individuals. But the number of people suffering a reaction is small when investigated by randomised controlled trials (RCTs), and much rarer than an allergy/intolerance to a natural food.

Are there banned additives?

Yes, some additives that were approved for use have been withdrawn from the food supply (e.g. E103, E105) because the safety tests on them are constantly reviewed.

How are dietary intakes of food additives monitored?

Food surveillance studies looking at levels in samples of foods and using national data (e.g. National Diet and Nutrition Survey, NDNS) to estimate intake in highest consumers versus ADI were carried out in the UK by the Ministry of Agriculture, Fisheries and Food (MAFF) and now by the FSA. The FSA are responsible for monitoring their use and taking appropriate steps to ensure that intake does not exceed recommended levels. Reports on intakes are also published by the European Commission.

The Labelling of the Southampton Six

Until recently, foods containing any of the six Southampton colour additives were not required to carry a health warning whilst medicines were. However, the EU labelling directive has been amended and, as of July 2010, a new legislation has been enforced that requires “labelling of the six Southampton colours with a warning that they may have an adverse effect on activity and attention in children.”[i]

There is no evidence that our intakes of these additives from foods and drinks cause any problems for the majority of the population (Sara Stanner, senior nutrition scientist). Pre 2010, medicines containing some artificial colourings carried health warnings when foods did not as they were being controlled by different legislations. Medicines need to alert consumers of any possible reactions to any of their ingredients.

Currently, foods containing additives must comply with the general labelling for food products in compliance to Directive 2000/13/EC. For more information please read

“Even organic foods can contain additives — currently 29 additives are approved for use in organic foods.”

Nigel Denby, nutrition consultant

The cocktail effect

Concern has been expressed about the multiplicative or ‘cocktail’ effect. Safety tests look at the effects of levels of one additive. Although less is known about the cumulative effect of exposure to multiple additives, chemically speaking, such effects are rare and scientifically well-understood. What the cocktail description usually implies is that, while individual substances may be considered safe at current levels of exposure, they may interact with each other and create unforeseen effects. But the natural world is a ‘cocktail of chemicals’ so our bodies are used to dealing with a mix of substances. The same processes of storing, neutralising, breaking down and excreting occur when we encounter new substances.

Food additives are not a new phenomenon

For centuries people have enhanced their food with naturally available flavourings, preservatives and dyes. With our increasingly complex food supply food additives play a vital role. Never before has the range and choice of foods been so wide either in supermarkets, specialist food shops or when eating out. As consumers we are demanding more variety, choice and convenience alongside higher standards of safety and wholesomeness at affordable prices. Meeting these consumer expectations can only be achieved using modern food processing technologies which include the use of a variety of food additives proven effective and safe through long use and rigorous testing. Without additives bread would become stale very quickly, fatty foods would turn rancid and most tinned fruits and vegetables would lose their firmness and colour. Even organic foods can contain additives — currently 29 additives are approved for use in organic foods. Nigel Denby, nutrition consultant Read Nigel’s full article here [LINK]

Find out more about food additives

Some useful resources are:

British Dietetic Association (professional association for dietitians in the UK):

British Nutrition Foundation (site providing healthy eating information):

Food Standards Agency (government department to protect the public’s health and consumer interests in relation to food):

Food and Drink Federation (voice of the UK food and drink manufacturing industry):

Food Additives & Ingredients Association: 

In 2013, Sense About Science published a briefing document on misconceptions about food additives Making Sense of Food Additives.