Do genetically modified (GM) foods cause cancer?

  • There’s no evidence that eating genetically modified foods causes cancer in humans
  • GM foods are not common in the UK
  • The main use of UK GM crops, such as maize and soybean, is in animal feed

There’s no evidence that genetically modified (GM) foods cause cancer in humans. And there aren’t any good explanations for how GM foods could cause cancer.

In the US, where GM foods are more common, we haven’t seen more cases of cancer linked to their introduction in the 1990s.


What are GM foods and GMOs?

Genetic modification is when the genes of a living thing have been changed or added to. Genes carry instructions for plants and animals to function.

Genetic modification means plants or animals can be changed to have a specific quality, such as being more resistant to disease. These plants and animals are called ‘genetically modified organisms’ (GMOs).

GM foods are foods that are made using genetically modified plants or animals (GMOs). They are not common in the UK. The main use of common GM crops, such as maize and soybean, is in animal feed.


Should I avoid eating GM foods and GMOs?

You don’t need to avoid GM foods to reduce your risk of cancer. But there are other ways to reduce the risk, including eating a healthy balanced diet

Some people worry that GM foods are unnatural and might be harmful. But it’s useful to remember that we have been changing genes of living things for hundreds of years, by selecting plants and animals to breed. This process changes the genes of the things we eat, but it’s also not linked to cancer. 

Because GM foods are relatively new, research continues to make sure that there aren’t any long-term health effects.


How do I know if my food contains GM ingredients?

In the UK, foods have to be labelled as GM if they contain genetically modified plants or animals.

GM foods can only be sold if the Food Standards Agency judges that they:

  • Do not present a risk to health
  • Do not mislead consumers
  • Do not have less nutritional value than their non-GM counterparts


GM foods are one of many cancer myths. But there are things that have been proven to cause 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.

National Academies of Sciences E, and Medicine; Division on Earth and Life Studies; Board on Agriculture and Natural Resources; Committee on Genetically Engineered Crops: Past Experience and Future Prospects. Human Health Effects of Genetically Engineered Crops. Genetically Engineered Crops: Experiences and Prospects. Washington (DC): National Academies Press (US); 2016.

Snell C, Bernheim A, Berge JB, et al. Assessment of the health impact of GM plant diets in long-term and multigenerational animal feeding trials: a literature review. Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association. 2012;50:1134-1148.

Food Standards Agency. Genetically modified foods. Vol 2019. FSA; 2018.


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