Do artificial sweeteners cause cancer?

  • No, the best evidence shows that artificial sweeteners, like aspartame, do not increase the risk of cancer
  • Artificial sweeteners are used in some food and drink instead of sugar
  • Your overall diet (what you eat day-to-day) is more important than individual ingredients or foods for reducing your cancer risk

Artificial sweeteners are in lots of different products. These include soft drinks and desserts, as well as things like chewing gum and toothpaste.


Do aspartame and other artificial sweeteners cause cancer?

No, artificial sweeteners such as aspartame don’t cause cancer.

You might have seen stories about artificial sweeteners and cancer on social media or the news. But the best evidence in humans does not show a link.

The European Food Safety Authority (EFSA) has also reviewed the evidence. They ruled that artificial sweeteners aren’t harmful within daily limits. These limits are more than most people would have on one day. For aspartame, the daily limit is equal to 12 cans of diet pop.


What are artificial sweeteners?

Artificial sweeteners replace sugar in some food and drink. They give a sweet taste with fewer or no calories.

Products with artificial sweeteners are often advertised as ‘diet’, or low or zero sugar.

There are lots of artificial sweeteners, including aspartame, saccharin, sorbitol and xylitol. They are all chemical substances that taste sweet.  


Does diet soda or diet pop cause cancer?

No, artificial sweeteners in diet or zero-sugar fizzy drinks don’t cause cancer.

Some drink companies use artificial sweeteners in place of sugar. This means that these drinks have fewer calories than if they just used sugar. They are sometimes chosen by people who want to lose weight.

Low-calorie drinks with artificial sweeteners can be part of a healthy, balanced diet.

There are many cancer myths, including artificial sweeteners, that haven’t been proven to cause cancer. However, there are proven causes of cancer, and things you can do to reduce your risk.


We regularly review new research on the causes of cancer to make sure our information is up to date and based on the best quality evidence. We develop our information by looking at lots of research carried out over many years. So, although new research comes out all the time, it is unlikely that one new study would change our position on a topic.  

Some studies are better than others at telling us about how different factors affect cancer risk. These are some of the things we consider:

  • Did the study look at cells, animals or people?

Studies in animals and cells can help scientists understand how cancer works, but they can’t always tell us how it’s relevant to humans. So we focus on studies in people.

  • How big is the study and how long did it go on for?

Studies on small numbers of people aren’t as reliable, because results are more likely to happen by chance. And studies that only follow people for a short amount of time can miss long-term effects. So we mainly look at studies that follow thousands of people over many years.

  • Did the study account for other factors that could affect someone’s cancer risk?

There are lots of factors that can affect someone’s risk of cancer. Studies should take known risk factors into account. For example, if a study is looking at air pollution and lung cancer, it should also look at whether participants smoked.

  • Where is the study published and who funded it?

It’s important to see if a study is published in a peer-reviewed scientific journal. This means that other experts have checked the results. It’s also important to know who funded the study, as this can affect the findings. For example, Cancer Research UK disregards research funded by the tobacco industry.

How to find accurate information on cancer

Sometimes news outlets exaggerate stories about cancer. It’s helpful to think about some of the questions above to judge a news story. But the most important thing is to get information from a trusted source– for example our website and the NHS.

One way of knowing if you can trust health information is by checking if the Patient Information Forum (PIF) has accredited it. The PIF makes sure that information is based on up to date evidence and is high quality.

The Patient Information Forum tick looks like this.

Patient Information Tick

You can read more about spotting fake news on cancer on our blog.


Boyle P, Koechlin A, Autier P. Sweetened carbonated beverage consumption and cancer risk: meta analysis and review. European journal of cancer prevention : the official journal of the European Cancer Prevention Organisation (ECP). 2014;23:481-490.

 (EFSA) EFSA. Scientific Opinion on the safety of advantame for the proposed uses as a food additive. EFSA Journal. 2013;11.

NHS. The truth about sweeteners  [updated 28 February 2019. Available from:]


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