Ask the experts: Aspartame

We sort fact from fiction about the artificial sweetener aspartame.

I've heard a lot about aspartame in the media lately. Should I be drinking diet drinks? Are they safe?

Diet drinks, and other foods containing the low-kilojoule sweetener aspartame, are entirely safe to include in your diet. We know this because there has been an incredible amount of research on aspartame over many years.

There has recently been a lot of misinformation about aspartame in the media. This may explain why, during 2008, volume sales of diet drinks have fallen by 5% while sales for regular soft drinks have increased by 9%.

In September 2008, Professor Bernadene Magnuson was in New Zealand talking about aspartame. She was lead author of an independent panel of nine toxicologists who reviewed the safety of aspartame in 2007. After viewing hundreds of studies and reports, they concluded aspartame is a thoroughly studied sweetener, with a long history of safe use in food, which can help reduce the energy content of many foods.

But wasn't that review funded by the food industry, who use aspartame in their products?

It has been reported Coca-Cola paid for Professor Magnuson’s travel expenses to visit New Zealand and speak about the panel findings. This has led many people to assume Coca-Cola must have influenced the findings of the review panel, and the review could not be independent.

This is not true. None of the panelists had ever undertaken research paid for by, or had any association with, any industry group associated with aspartame.The review was commissioned ‘blind’, which means the panel did not know who funded its work, nor did the funders (Ajinomoto) know who was on the panel until after the review was accepted for publication. In fact, a number of the authors went into the process thinking they might find evidence of an adverse effect, but after examining the research, all were convinced of aspartame’s safety.

I've heard stories of people having all kinds of illnesses attributed to artificial sweeteners. Is this right?

Some people may believe they’ve experienced adverse symptoms from high consumption of aspartame-containing foods. It’s important to note these individual anecdotes are not the same as scientific evidence. At HFG, we are guided by the established body of evidence on any topic. When new evidence emerges, we take it into account. Right now, there is no scientific evidence of the claimed side effects of aspartame or even a feasible biological explanation for them.

Doesn't aspartame break down into methanol? That sounds bad for me.

Aspartame produces methanol which breaks down into formaldehyde and formic acid in the body. Don’t be alarmed by the names. These are normal by-products of metabolism which in turn break down to carbon-dioxide and water.

Aspartame is manufactured by joining two amino acids, aspartic acid and phenylalanine. These amino acids are found naturally in protein-containing foods. Aspartame is completely broken down in the digestive system into the two amino acids and methanol.

Methanol also occurs naturally in foods: it’s found in fruit juices, fruits and vegetables. A soft drink containing aspartame provides one-fifth of the methanol as the same amount of tomato juice.

What do HFG experts recommend?

There are many healthy drink choices: water, juice, different teas, coffee, milk... It’s possible to live life without soft drinks, diet or otherwise, and other products containing aspartame. They’re not a necessary part of anyone’s diet. So if, for any reason, you want to avoid aspartame, it’s not difficult. Aspartame appears in the ingredients list either by its name or number (951). Products containing aspartame also state ‘contains phenylalanine’. But if you like soft drinks and you’re concerned about weight-gain, or keen to consume less sugar, we recommend you consider the diet versions. Sugary drinks are not something you should have every day. Remember, water is your best choice.