Food additives

Food additives: What are they?

Food additives are chemicals that are added to food to improve its shelf-life, appearance and flavour. There are hundreds of additives. Examples include ascorbic acid, which is used to prevent food from going off, emulsifiers to help mix oil and water together, and active packaging that improves the quality or safety of food.

What are the risks from food additives?

The possible health risks of food additives are the subject of fierce controversy. However, food additives allowed by law in the UK are generally considered safe.

But there are some chemicals used in food that certain people should look out for. One particular one is phenylalanine. Phenylalanine is a naturally occurring essential amino acid found in all protein (including mother's milk). It’s also used in the manufacture of various foods and is a constituent of the artificial sweetener aspartame.

However one in 8-12,000 babies is born without the ability to metabolise phenylalanine from any dietary source. This condition is called phenylketonuria. If phenylalanine isn’t metabolised, toxic levels build up in the blood and can result in brain damage.

All children in the UK are screened for phenylketonuria shortly after birth and those with the condition must follow a strict diet to limit phenylalanine intake especially while their brains are developing, until adulthood. So people with this condition need to be aware of the use of phenylalanine as a food additive.

A similar example is lactose intolerance. A significant proportion of the population loses the ability to digest the milk sugar lactose after childhood.

Lactose intolerance is especially common among people of Asian or African origin. Those with the condition must limit their intake of milk and dairy foods or they will develop symptoms such as:

• Indigestion.
• Abdominal bloating.
• Nausea.
• Diarrhoea.

But lactose is a very common food additive, used in the manufacture of many items from biscuits and crisps even to medicines, so people with lactose intolerance need to study labels carefully.

Other additives highlighted as causing problems for some people by The Center for Science in the Public Interest (CSPI), a US organisation that campaigns for food safety, include:

• Caffeine: linked to peptic ulcers, insomnia, nervousness and possibly even birth defects.
• Monosodium Glutamate (MSG): linked to headaches, tightness in the chest, and a burning sensation in the forearms and back of the head.
• Nitrite and Nitrate: Meat preservatives that can form powerful cancer causing chemicals when heated.
• Saccharin: this has been linked to cancer in laboratory animals. However the real risk to humans remains a matter of controversy.

What are the recommendations?

All additives in the UK and Europe are controlled by law, and can only be used following stringent tests and approval by an independent committee of scientists and medical experts.

However, some scientists have linked additives in general use, particularly tartrazine or E102 to:

• Hyperactivity in children.
• Allergies.
• Asthma.
• Migraines.
• Cancer.

For example, several studies, such as one in The Lancet in 2007, have now been published which show additives such as colourings or sodium benzoate can adversely affect the behaviour of children aged between three and nine years old.

But the topic remains under lively debate. The British Nutrition Foundation (BNF) believes more research is needed before any firm link is established between additives and allergic reactions. But it doesn't rule out the possibility.

According to the CSPI many additives should be avoided for health grounds, but not all UK experts agree with this.

If you’re worried that a particular additive may be causing your symptoms then it may be worth trying an elimination diet, where you remove that substance completely from your diet and see if the symptoms get better. If symptoms then return when you start eating foods containing the additive again, it may be contributing to your problems and may be best avoided.

If problems persist, or you’re worried about symptoms your child is having (elimination diets should only be done under supervision in children), ask you GP if you can talk to a dietician – you may have to wait some time as services are very limited.