Features

The hard facts on food additives

by Bianca Nogrady

Most food that comes in a packet or container contains at least some food additives. But what are these little three digit numbers and are they really a cause for concern?



[Image source: iStockPhoto | IgorDutina ]

Reading the ingredient list on packaged food can leave you feeling bamboozled. Especially when it comes to the names and numbers of food additives, which are often completely unidentifiable and unpronounceable.

But despite our confusion, the food additives in our tins of tomatoes, tubs of margarine, or jars of jam are there for a variety of reasons. They may stop your food going off, improve its taste or appearance, or keep the ingredients from separating.

Food Standards Australia's chief scientist Dr Paul Brent says: "a food additive is any substance that is not normally consumed as a food in itself and is not normally an ingredient, but which is allowed to be there if it fulfills a technological function in the final food".

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Why do we need them?

We've been using ingredients to help us preserve and improve the taste of food for centuries and without certain additives many processed foods would be unsafe to eat, and if they weren't we wouldn't want to eat them anyway.

Some of the functions of food additives include:

adding or restoring colour to foods (artificial colours have code numbers in 100s)

preventing food from 'going off' (preservatives have code numbers in 200s)

slowing or preventing the oxidative deterioration of foods (antioxidants have code numbers in 300s)

improving the flavour of food (food enhancers have code numbers in the 600s).

"Consumers expect certain types of food to be certain types of colour so for example, if there are no colours we'd be eating clear margarine," Brent says.

He acknowledges many of us are not happy with the amount of additives in our food, but argues they are a necessity.

"There is general concern about the use of food additives, that they're not natural, why do we have them, that we should be eating organic food with no chemicals. But the fact is that with a lot of food, particularly in a large continent like Australia where food has to travel a fair way, you do need preservatives."

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How safe are they?

Food Standards Australia and New Zealand (FSANZ) closely monitors the use of food additives, which Brent says undergo comprehensive safety assessments and are subject to regulatory scrutiny similar to pharmaceuticals and chemicals.

"The amount of data we get for a food additive compares with the amount of data that other agencies, such as the Office of Chemical Safety or the Therapeutic Goods Administration get."

In addition, food additives are scrutinised by the World Health Organisation, the United Nations Food and Agriculture Organisation and its joint expert committee on food additives.

Dr Anne Swain, dietitian from Royal Prince Alfred Hospital's allergy unit, says usually food additives aren't a problem. But they can become an issue when overconsumed, or if someone with a sensitivity to a particular additive consumes them.

The amount of an additive food manufacturers are able to add to foods is based on tests of what is reasonable and safe, not only at normal levels of consumption, but also allowing for overconsumption.

"Could you overconsume? Yes. But generally the levels that are allowed [to be added to foods] are taking that into account."

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Food additive intolerances

Around 5 per cent of the general population are sensitive to one or more food additives, says Dr Rob Loblay, head of the allergy unit at Sydney's Royal Prince Alfred Hospital.

"For some people it's a minor problem that only bothers them if they have way too much of something. For other people, who are very sensitive, it can be a significant problem and if they happen to have asthma it can be a serious problem," says Loblay.

He points out intolerances to food additives are not food allergies; they don't tend to involve the immune system and don't show up on allergy tests. Also intolerances are unlikely to cause life-threatening reactions such as anaphylaxis, even though they can still make you very unwell.

"It's a dose effect  often a little bit is not a problem, a bit more can be a problem, too much can be a problem. But that's a very individual thing. Each person needs to work out how much is too much for them of which particular additive," Loblay says.

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Problem additives

Much of the concern about food additives has been based on certain groups.

Preservatives have been associated with intolerances, particularly among people with asthma. Sulfites (including sodium bisulphite (222), sodium metabisulphite (223) and potassium bisulphite (228)) found in wine, beer and dried fruit, are known to trigger asthmatic episodes and cause migraines in people who are sensitive to them. Also sodium nitrate (251) and sodium nitrite (250), which are used in processed meats, have been classified as 'probably carcinogenic to humans' by the International Agency for Research of Cancer (IARC).

Flavour enhancer monosodium glutamate (MSG) (621) is often used in Asian cooking and has been associated with 'Chinese Restaurant Syndrome' (a collection of symptoms including headache, numbness and tingling that some people experienced after eating foods containing MSG). While numerous studies have found MSG is safe for most of us, some people experience symptoms if they eat a large amount of MSG in a single meal.

Food colourings, such as tartrazine (102), allura red (129) and ponceau 4R (124), are often credited as the cause of hyperactivity in children. In 2007, a team of researchers from the University of Southampton in the UK studied food colourings and additives, and their effect on children's behaviour. The authors of the Southampton study concluded there was a link between hyperactivity and food colourings (and one preservative) in children aged three and eight to nine years old.

Says Loblay: "It created this enormous wave of concern, as well as lobbying by various interest groups to ban additives from the market, or to ban colourings from market, or to ban them from schools. There was a big push to ban things and it caused some concern for the food authorities because they felt that it was all a bit overblown and so did we."

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Natural additives

He says the distinction between 'artificial' and 'natural' food additives, is misguided because almost everyone who is sensitive to an artificial additive will also be sensitive to one or more natural substances.

"Sometimes the additives and the natural substance are chemically identical, sometimes they're chemically closely related and the distinction between natural and artificial is completely artificial."

Swain says the main difference between these compounds in 'natural' versus processed foods is concentration.

"When you're talking about the natural chemicals in food, you'll get a small amount of these compounds naturally occurring in food but when you get them as an additive, you get a large dose in one hit," says Swain.

However, she stresses that for the majority of people, the nature and levels of additives in our food supply are not an issue as long as they are consumed in moderation.

"I'm not saying that people should have lots of colours, preservatives etcetera, but I'm equally not saying it should be banned from our food supply," Swain says.

"I think there's too much junk out there but for those that want to eat junk, it's there."