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Aspartame – what it is and why it is used in our food

This page explains what aspartame is, what it’s made of and how we know it’s safe. It also provides links to food authorities around the world, so you can find out what they say about aspartame.

A safe alternative to sugar

Aspartame is a low calorie sweetener that has been used as a safe alternative to sugar in a range of foods, including carbonated soft drinks, yoghurt and confectionery for more than 25 years. It is at least 200 times sweeter than sugar.

NZFSA, the New Zealand Ministry of Health and food safety authorities around the world believe that aspartame has a place in the diet of people who wish to reduce their intake of sugar – either because they are diabetic or are concerned about their weight. Unlike sugar, aspartame does not cause tooth decay.

How the body processes aspartame

Aspartame consists of two amino acids (aspartic acid and phenylalanine – found naturally in foods that contain protein such as meats, grains and dairy products). Amino acids are basic building blocks for proteins in the human body.  During the digestive process, aspartame is broken down into three products - aspartic acid, phenylalanine and methanol.

These products are absorbed, metabolised further and excreted by normal body processes. Even with relatively high doses, the metabolites of this sweetener are not harmful. Methanol, while toxic at high doses, is produced in such small amounts from ingested aspartame that the body easily handles it naturally without any problems, as it does with the methanol resulting from the digestion of fats, fruits and vegetables.

Acceptable daily intake for aspartame

The Acceptable Daily Intake (ADI) is the amount of an additive that someone could eat in the course of a day, and every day for their whole lives, without showing any adverse health effects. The ADI for aspartame was established at 40 milligrams per kilogram of body weight (40 mg/kg bw) by JECFA, a panel of experts convened regularly by the World Health Organization and the UN Food and Agricultural Organization. This is one of the highest ADIs established for any food additive, reflecting its high level of safety. To exceed the ADI, an adult weighing 70 kilograms would have to drink between 15 and 20 cans of diet carbonated soft drinks per day, every day for their entire lifetime. As ADIs have wide safety margins built into them, even at this level of intake you are unlikely to experience ill-effects due to aspartame. At this level of consumption, however, you may suffer ill-effects caused by other ingredients in the drink.

How to identify aspartame in food

Look for the additive numbers 951 or 962, or aspartame listed in the ingredients on the label. There is also a warning statement that the product contains phenylalanine.

Aspartame and phenylketonuria

Some people have the rare inherited disease phenylketonuria (PKU) and are advised not to consume aspartame because they have limited ability to metabolise the amino acid phenylalanine, which could accumulate to potentially harmful levels.

People with PKU need to follow a very strict diet to limit their intake of phenylalanine, which is also found in all proteins as well as aspartame.

All food products containing aspartame or its acesulphame salt are required to state they contain phenylalanine.

Regulation of aspartame in New Zealand

In New Zealand, only those artificial sweeteners listed in the Joint Australia/New Zealand Food Standards Code are permitted, and any listed have been assessed for safety by Food Standards Australia New Zealand (FSANZ). Aspartame is one of these. The Food Standards Code also sets out which foods can have aspartame added to them.

Permitted levels of sweeteners in foods are established only after taking into account how much is likely to be eaten and the acceptable dietary intake levels set by JECFA. (For a full list of sweeteners, see NZFSA’s fact sheet Intense Food Sweeteners).

Aspartame is approved in other countries

Aspartame has been assessed as safe by all the major food authorities around the world, including the European Food Safety Authority, the United Kingdom Food Standards Agency, the Canadian Food Inspection Agency, the Food Safety Authority of Ireland, and the United States Food and Drug Administration. These official government bodies are committed to protecting consumers in their countries and have found aspartame to be a safe product.

How we know aspartame is safe

Claims are made from time to time about the potential for aspartame to cause cancer or other health problems. At least five robust published studies have looked into this. All have been reviewed by regulators around the world, and all have concluded that aspartame demonstrates no such potential. Even with high doses, the metabolites of this sweetener do not accumulate in toxic amounts. If you need or wish to limit your intake of sugars, and/or reduce your energy intake, there are clear benefits in consuming foods sweetened with aspartame or other artificial sweeteners. Aspartame is well tolerated by healthy adults and children.

People concerned about aspartame often cite the findings of the European Ramazzini Foundation of Oncology and Environmental Sciences (ERF) which considered that its results indicate that aspartame is linked to many different kinds of cancers. However, regulatory authorities, including NZFSA and FSANZ, are satisfied that the science shows that aspartame does not cause cancer.

The European Food Safety Authority’s Scientific Panel on Food Additives, Flavourings, Processing Aids and Materials in Contact with Food (the AFC Panel) have found flaws in the ERF study which bring into question the validity of the findings.

As part of its review of the ERF studies, the AFC Panel examined evaluations of aspartame by the European Scientific Committee on Food and other expert bodies which found no links to cancer; it also considered an epidemiological study involving over 100,000 people carried out by the US National Cancer Institute in which no increase in brain or blood related cancers was reported to be associated with aspartame consumption; and it reviewed comprehensive studies indicating that aspartame does not affect DNA.

On the basis of the scientific evidence, the AFC Panel concluded that there is no reason to revise the previously established ADI for aspartame of 40 mg/kg bw. The Opinion of the AFC Panel was adopted on 3 May 2006 and is available on www.efsa.europa.eu The Panel monitors and evaluates new evidence as it comes to hand, and publishes its findings on the EFSA website.

Related links

Aspartame – NZFSA fact sheet March 2009 [PDF]

Intense food sweeteners

Intense food sweeteners – NZFSA fact sheet March 2009 [PDF]

Consideration of issues concerning aspartame – address to Health Select Committee

ESR report on Aspartame

What other food safety authorities say about aspartame

European Food Safety Authority’s assessment of aspartame [EFSA]

United States Food & Drug Administration lists aspartame as approved [USFDA]

Canadian Food Inspection Agency dispels aspartame claims [CFIA]

Food Standards Australia New Zealand aspartame fact sheet July 2009 [FSANZ]

January 2010