Diet cola myths exposed

Will it really help you lose weight, or protect your teeth?
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  • Updated:16 Mar 2007

02.Artificial sweeteners

What sweeteners are used?

The diet colas in our test contain no sugar but they’re sweetened with artificial sweeteners. Drinks usually contain at least two sweeteners because manufacturers have found that combinations give a quality of sweetness that’s more like sugar than any one sweetener on its own.

You can identify the sweeteners from the code numbers on the label:

  • Acesulphame potassium (950)
  • Aspartame (951)
  • Cyclamate (952)
  • Saccharin (954)
  • Sucralose (955)

These substances can be many hundreds of times sweeter than sugar so the amounts you get in your drink are very small.

Are they safe?

  • There have been reports linking many of these artificial sweeteners to increased risk of cancer. In the 1970s several studies of rats fed very large amounts of saccharin raised concerns about its safety, and as a result it was banned in Canada and until 1996 products containing saccharin in the USA had to be labelled with a warning.
  • It was much the same with cyclamate. A study found that it increased the risk of bladder cancer in rats and as a result its use was banned in Canada and the USA, and in the UK it was banned until 1996.
  • And aspartame has been linked to a variety of health problems ranging from Gulf War Syndrome to increased risk of brain and breast cancers.
  • But most of these claims for the various sweeteners have failed to stand up conclusively to rigorous scientific examination. Last year, for example, a European report claimed aspartame causes a number of different cancers, whereas an independent panel of experts looking at the same research results found no compelling evidence for aspartame being harmful at the levels permitted in foods and drinks.
    With these controversies widely reported in the media it’s not surprising that a quarter of adult Australians now believe artificial sweeteners cause cancer. Experts, though, are generally convinced that any risks are small. And you have to balance these small risks against the very substantial risks to your health from being overweight.

As long as there’s no absolute certainty, experts recommend we limit our intake of artificially sweetened foods and drinks. Recent surveys have found that some consumers (mainly children) are now exceeding the acceptable daily intake (ADI) for cyclamate. The ADI is the ‘safe’ level recommended by scientific experts; there’s a substantial safety margin and consuming more than the ADI over a short period isn’t necessarily a health risk, but on a regular basis there might be cause for concern.

“Contains phenylalanine”

You’ll see this warning on any product sweetened with aspartame.

When aspartame breaks down in the body, one of the products is the amino acid phenylalanine. This is a health hazard for people born with the rare hereditary disease phenylketonuria (PKU). Their bodies have a problem breaking down phenylalanine, so it builds up in the blood to levels that can cause brain damage.

To prevent this from happening they have to limit their intake of phenylalanine from all sources, including common protein foods such as meat and milk.

Chance discovery

Some artificial sweeteners were discovered by chance — or sloppy laboratory practices.

  • Ira Remsen, one of the discoverers of saccharin (in 1879), was working on the chemistry of compounds made from coal tar, but noticed a sweet taste after not thoroughly washing his hands before dinner.
  • Michael Sveda was developing an anti-fever drug when he discovered cyclamate. He was a smoker and noticed a sweet taste after momentarily putting his cigarette down on the lab bench.

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