Food myths

  • This page explains what the evidence really says about different foods causing or preventing cancer.
  • Food from the UK and EU is produced to strict standards.
  • There is no good evidence that any one food prevents cancer, including ‘superfoods’. But you can reduce your risk by keeping a healthy weight and eating a healthy balanced diet.

What are carcinogenic foods?

If something is carcinogenic, it means that it could cause cancer. There aren’t many foods that cause cancer, but eating processed and red meat can increase the risk of bowel cancer. Read on to find out about other food types.  

 

Does acrylamide or burnt food cause cancer?

Eating burnt food does not cause cancer.

Foods such as burnt toast or crispy potatoes contain a naturally occurring chemical called acrylamide. This chemical is created when certain foods are cooked at high temperatures for a long time. It’s also found in biscuits, coffee, bread, crisps and chips.

You don’t need to avoid acrylamide to have a healthy balanced diet. But some foods with acrylamide can make it harder to keep a healthy weight.  

Read more about acrylamide and cancer.

 

Do artificial sweeteners cause cancer?

Artificial sweeteners such as sucrlose or aspartame can be found in lots of products from diet versions of fizzy drinks to chewing gum. They do not cause cancer in humans.

In the UK, the type and level of sweeteners that can be used in food is set by the Sweeteners in Food Regulations.

Read more about artificial sweeteners and cancer.

 

Can green tea prevent cancer?

Green tea and matcha (powdered green tea) do not reduce the risk of cancer.

Some people have suggested that green tea might reduce the risk of cancer. This is because it contains catechin - an antioxidant that seems to stop tumour growth in rats.

But results from large studies have not shown that green tea reduces the risk of cancer in humans.

 

Does eating soy (soya) prevent cancer?

Eating soy products does not affect cancer risk.

Soy products and breast cancer

Soy products such as tofu and soy milk contain chemicals called isoflavones. These are like the human hormone oestrogen, but have much milder effects. The link between soy and breast cancer has been studied in humans. But there is no good evidence that eating soy products increases or decreases cancer risk.

 

Can superfoods prevent cancer?

The word ‘superfood’ is used to talk about foods that are supposed to improve health and prevent diseases like cancer, but this is not backed up by science. You might have heard people call blueberries, broccoli, raspberries and other fruits and vegetables ‘superfoods’.

It’s true that a healthy, balanced diet can help to reduce the risk of cancer, but it is unlikely that any single food will make much of a difference on its own.

 

Can tomatoes cause or prevent cancer?

No, eating fresh or tinned tomatoes does not affect cancer risk.

Eating tinned tomatoes does not cause cancer. Some tins and cans are lined with something called Bisphenol-A (BPA). Eating food that has been stored in BPA-lined tins does not cause cancer.

Eating tomatoes doesn’t prevent cancer. Some studies have looked at whether eating tomatoes might help prevent prostate cancer. These studies focused on a chemical in tomatoes called lycopene. But there is no good evidence that lycopene reduces overall cancer risk or the risk of prostate cancer.

Even so, tomatoes, like other fruits and vegetables, can still be part of a healthy balanced diet.

 

Can eating sugar, including refined sugar, cause cancer?

Eating sugar doesn’t cause cancer.

Refined sugar comes from sugar cane and sugar beets. There’s no good evidence that refined sugar or other types of sugar cause cancer.

But too much sugar in our diets can make it harder to keep a healthy weight. And being overweight or obese does increase the risk of cancer.

Read our blog for more information on sugar and cancer.

 

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.

British Nutrition Foundation. Find your balance get portion-wise. https://www.nutrition.org.uk/attachments/article/1193/Find%20your%20balance_%20booklet.pdf(link is external). Accessed: November 2020.

Brown KF, Rumgay H, Dunlop C, et al. The fraction of cancer attributable to modifiable risk factors in England, Wales, Scotland, Northern Ireland, and the United Kingdom in 2015. British Journal of Cancer. 2018;118:1130-1141

Mishra A, Ahmed K, Froghi S, Dasgupta P. Systematic review of the relationship between artificial sweetener consumption and cancer in humans: analysis of 599,741 participants. International journal of clinical practice. 2015;69:1418-1426.

Pelucchi C, Bosetti C, Galeone C, La Vecchia C. Dietary acrylamide and cancer risk: an updated meta-analysis. Int J Cancer. 2015;136:2912-2922.

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