You are here

Podcast | Aspartame – what is it and is it safe?


Can artificial sweetener really have negative impact on our health?

Nutrition expert Chris Forbes-Ewan sheds light on the debate surrounding the health effects of artificial sweetener.


Kenny Gregory: In today’s podcast: we visit the debate around the health effects of Aspartame, more commonly known as artificial sweetener.

[Music plays]

Kenny Gregory: Should we stop substituting sugar for artificial sweeteners? Can these substitutes really have negative impact on our health?

[Music ends]

Kenny Gregory: Hi, I’m Kenny Gregory with another podcast from Defence Science and Technology.

Chris Forbes-Ewan is a nutrition expert, who has had more than 25 years experience as a Defence nutritionist. He has conducted extensive research on the nutritional requirements of soldiers across a wide range of military occupations. For nearly two decades Chris has also represented Australia on international technical panels aimed at improving the health, nutritional status and military performance of troops.

Chris Forbes-Ewan: Although most scientific discoveries are the result of directed experimentation, sometimes new and useful discoveries are entirely attributable to luck. The word used to describe an unexpected stroke of luck of this kind is ‘serendipity’.

A good example of serendipity is the origin of aspartame, the most commonly used artificial sweetener. In 1965, a chemist who was working with amino acids (which are the building blocks of protein) combined two amino acids—aspartic acid and phenylalanine—to create a new chemical.

Although it is a fundamental safety rule in chemistry laboratories that you never place any chemical you are working with in your mouth, this chemist inadvertently managed to achieve this. He didn’t realise that some of the novel chemical had spilled on the bench and a small quantity was transferred to his mouth when he licked his finger to pick up a piece of paper.

Completely unexpectedly, he found that by combining two of the building blocks of protein (which has no sweetness) he had created a substance that has a level of sweetness about 200 times that of sugar!

Aspartame (as the new artificial sweetener was called) is so powerful that only a minute quantity is needed to sweeten a cup of tea or coffee. Consequently, it provides virtually no kilojoules, so unlike sugar (which provides about 70 kilojoules per level teaspoon) aspartame is a ‘non-nutritive’ sweetener.

Aspartame was subjected to safety testing for many years, and was finally approved for use in foods and beverages in Europe and the United States in the 1980s. It is also approved for use in a wide range of foods in Australia and New Zealand, where it is most commonly sold under the brand names Nutrasweet or Equal.

For many years, there have been claims that aspartame was originally developed as an ant poison, and that its use is associated with many health problems, including birth defects, lupus, brain damage, and severe seizures.

Despite more than 50 years of research finding no credible evidence for these claims, they appear to be endlessly circling the internet. 

Although the wilder claims about harmful effects attributable to aspartame can be safely dismissed as quackery, more attention deserves to be given to a claim that artificial sweeteners, including aspartame, may be associated with the onset of cancer. This is because rat studies have shown an association between the consumption of these sweeteners and cancer incidence.

However, an association does not prove cause and effect. In any case, as the World Cancer Research Fund pointed out in a comprehensive report published in 2007, the rat studies involved intakes that were ‘far greater than humans could consume in foods and drinks’. The World Cancer Research Fund concluded in its report that ‘The evidence … does not suggest that chemical sweeteners have a detectable effect on the risk of any cancer’.

In 2010, the European Food Standards Agency (EFSA) reviewed two studies that indicated a slight increase in adverse health outcomes that may be attributable to aspartame and concluded that these studies ‘do not give reason to reconsider previous safety assessments of aspartame  ...’ That is, aspartame still appeared to be safe for human consumption.

However, the European Food Standards Agency accepted that the safety of aspartame hasn’t been unequivocally demonstrated, only that harmful effects haven’t been found. This is an important point, which is reflected in the following wording from their 2010 report: ‘... the EFSA will continue monitoring the scientific literature in order to identify new scientific evidence for sweeteners that may indicate a possible risk for human health, or which may otherwise affect the safety assessment of these food additives.’

Despite this caveat, the latest report from the European Food Standards Agency, published in 2013, states that ‘There is no consistent evidence that aspartame has adverse effects, either in healthy individuals or in potentially susceptible groups …’

The 2012 Position Paper of the Academy of Nutrition and Dietetics—the peak nutrition and dietetics body in the United States—also endorses the safety of aspartame by stating that ‘... consumers can safely enjoy a range of nutritive sweeteners and non-nutritive sweeteners.’ In this context, non-nutritive sweeteners include not only aspartame, but also others commonly used in Australia, such as saccharin, sucralose, and stevia (which is derived from a South American plant, so is not technically an ‘artificial’ sweetener).

However, there is one potential adverse health effect associated with the use of aspartame. A genetic condition called phenylketonuria affects about one person in 10 000. People with phenylketonuria cannot metabolise phenylalanine—one of the two amino acids that combine to form aspartame—so those people need to minimise intake of all sources of phenylalanine, including aspartame.

So can I put my hand on my heart and swear that aspartame is safe for everyone other than people with phenylketonuria?

No, I can’t. But based on the evidence currently available, if I wanted to reduce my sugar intake yet still enjoy sweetened tea or coffee, I would have no hesitation in using aspartame (or any of the other approved non-nutritive sweeteners) to achieve this.

[Music plays]

Kenny Gregory: Great to hear Chris’s thoughts on this controversial topic.

For more science related discoveries, news and debates – follow us with @DefenceScience on Twitter and Instagram, or download the DST App from Google Play or the App Store.

The Defence Science and Technology podcast is a production of the Defence Science and Technology Group, part of Australia’s Department of Defence. That’s all for now. See you next time.


More information

Podcast Type


Publish Date

February 2017

Listen now

Listen and subscribe

Subscribe to the Defence Science podcast on iTunes, Stitcher and TuneIn, using the links below.

Listen to Stitcher