Food myths and cancer
- 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. 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.
Can eating sugar, including refined sugar, cause cancer?
Eating sugar doesn’t cause cancer. This is true for all types of sugar, including refined sugar.
But too much sugar in our diets can make it harder to keep a healthy weight. And being overweight or obese increases the risk of 13 types of cancer.
Read our blog for more information on sugar and cancer.
Does acrylamide or burnt food cause cancer?
Eating burnt food does not cause cancer.
Foods such as burnt toast or crispy potatoes contain a chemical called acrylamide. This is created when certain foods are cooked at high temperatures for a long time. But eating foods that contain acrylamide doesn’t cause cancer in humans.
Read more about acrylamide and cancer.
Do artificial sweeteners cause cancer?
No, artificial sweeteners don’t cause cancer.
Artificial sweeteners such as sucralose 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.
Read more about artificial sweeteners and cancer.
Do eggs cause cancer?
No, eating eggs does not cause cancer.
Studies have looked at the relationship between eggs and different types of cancer, but there is no good evidence that eggs affect cancer risk. Eggs can provide a source of protein as part of a healthy balanced diet.
Does eating tinned food cause cancer?
No, eating canned or tinned food does not affect cancer risk.
Some tins and cans are lined with something called Bisphenol-A (BPA). Some people have wondered if BPA affects cancer risk, but this is not backed up by good evidence. Eating food that has been stored in BPA-lined tins does not cause cancer.
Does eating soy (soya) affect cancer risk?
Eating soy products does not affect cancer risk, including 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. That’s why some people have wondered if there’s a link between soy products and breast cancer. But neither soy products nor isoflavones affect cancer risk.
Can any foods prevent cancer?
No single food can prevent cancer, but eating wholegrain foods that are high in fibre does reduce the risk of bowel cancer.
There are lots of myths about foods preventing cancer. We look at some of the most popular myths below.
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. But results from large studies have not shown that green tea reduces the risk of cancer in humans.
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 prevent cancer?
No, 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, which can help to reduce the risk of cancer overall.
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.
You can read more about spotting fake news on cancer on our blog.
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
Toews I, Lohner S, Küllenberg de Gaudry D, Sommer H, Meerpohl JJ. Association between intake of non-sugar sweeteners and health outcomes: systematic review and meta-analyses of randomised and non-randomised controlled trials and observational studies. BMJ. 2019 Jan 2;364:k4718. doi: 10.1136/bmj.k4718. Erratum in: BMJ. 2019 Jan 15;364:l156. PMID: 30602577; PMCID: PMC6313893.