Food Safety Authority challenges activists’ views on aspartame

3 August 2007

The New Zealand Food Safety Authority (NZFSA) is concerned that anecdotal claims made by anti-aspartame campaigners about the sweetener do not seem to be supported by actual evidence.

“The claims being made – and widely reported in the media – are doing a great public disservice,” says NZFSA Acting Chief Executive Dr Andrew McKenzie. “Aspartame is one of the most studied substances in the world and continues to retain one of the highest Acceptable Daily Intake (ADI) levels of any additive (40 mg/kg-bw).

“For those dealing with far more serious health issues, such as diabetes and obesity, using junk science to cast doubt on a proven, safe alternative to sugar is very disappointing.

“Aside from the aspersions these campaigners cast on the United States Food and Drug Administration, how do they explain the decision by other food safety regulators around the world, such as the United Kingdom Food Standards Authority and the European Food Safety Authority, to continue to allow its use? The fact is, a large amount of very good science shows that aspartame is a very safe substance. Studies that purport to show otherwise have thus far been overwhelmingly rejected by leading food safety authorities as flawed.

“If there is some robust yet until now unknown evidence that aspartame causes the raft of problems suggested then those campaigners, if they really care about public health, should make the evidence available for scrutiny. NZFSA would obviously consider any new, sound scientific evidence on aspartame, as it would – and does – on any food safety issues. But holding meetings and giving talks, as these activists are doing, cannot be classed as robust, sound science.”

NZFSA’s principal toxicologist John Reeve (who has over 30 years experience in toxicology, including serving on international expert consultations) says that people making these claims need to come clean about the credentials they have.

“Every right-thinking individual needs to ask ‘does this person have anything to say that’s backed by evidence?’ and ‘what are their qualifications for making these claims?’.

“Toxicological data is very complex and needs careful interpretation. As in all life sciences false positives and false negatives are a fact of life and expertise is required to properly interpret data from such studies. Over-simplistic interpretations lead to incorrect conclusions.

“Prime examples are recent Italian studies on rats which claimed to show that aspartame causes cancers. These studies were conducted in a way that could not possibly have provided any information about the toxicity of aspartame – or in fact anything else in the rats’ diet. The animals used were allowed to live until they died naturally, meaning that all the study did was show the results of ageing, which as we all know is a natural process that leads, inevitably, to death.

“In fact, the only conclusion that can be drawn from the results is that aspartame appears to be safe because the studies showed that those rats fed it (even at very high doses) lived as long (if not longer) as untreated rats, despite consuming up to more than 100 times the ADI every day of their lives. If aspartame was as horrendously toxic as is being claimed, it would be logical to expect the rats dosed with it to have shortened life-spans. The conclusions drawn by the researchers were clearly not backed up by their own data.”

Dr McKenzie is concerned that campaigns against aspartame, and the media coverage being given to them, could have health consequences for some at-risk people.

“Casting unfounded suspicions about aspartame – a safe alternative to sugar – could cause many to start consuming too much sugar, with the well-known and accepted potentially life-threatening effects associated with diabetes, obesity and similar.”

Anybody who wants to avoid foods containing aspartame can identify its presence from the label. Consumers can make informed choices because food manufacturers are required to list food additives and other ingredients, including sweeteners, on labels.


For further information contact: Diane Robinson, NZFSA Communications Advisor:
029 894 2528.

For further comment contact: John Reeve, NZFSA Principal Toxicologist: 029 894 2533.

Notes for editors

(An ADI is the amount of an additive that can be taken in daily over a lifetime without damaging people's health. It is expressed in relation to bodyweight (bw) to allow for different body sizes, such as for children of different ages.)