Can milk and dairy products cause cancer?
- There is not enough good evidence to prove that milk and dairy can cause cancer
- Eating and drinking milk and dairy products can reduce the risk of bowel cancer
- The NHS Eatwell Guide recommends having some dairy as part of a healthy, balanced diet
Eating and drinking milk and dairy can reduce the risk of bowel cancer. But there is no proof it increases or decreases the risk of any other cancer type.
This page is about dairy products and cancer risk for the general public. If you’ve had a cancer diagnosis, speak to your doctor if you have questions or concerns about your diet.
How do milk and dairy products decrease bowel cancer risk?
There is good evidence that dairy products decrease the risk of bowel cancer. This includes milk and cheese.
Dairy products contain proteins and vitamins that are important for your health. This includes calcium which is important for strong bones. And high calcium content could be one way dairy products decrease bowel cancer risk.
Dairy alternatives (particularly soya products), can also contain these important proteins and vitamins. Try to choose products with added with added calcium and B12.
Dairy-alternatives have important health benefits. But we need more research to know for sure if they can also reduce risk of bowel cancer.
Low fat, low sugar dairy or dairy-alternatives make up a part of a healthy, balanced diet.
What about other cancer types?
There is no strong evidence linking dairy products to any other types of cancer.
Prostate cancer risk and dairy
Research has not proven whether dairy or calcium has a direct effect on prostate cancer risk. There are some studies that have found an increased risk in people who have large amounts of dairy. But there’s not enough good evidence for this.
It’s hard to measure how much dairy people eat over a long period of time. And there could be other factors that are different in people who eat and drink a lot of dairy. It is unclear whether it’s dairy increasing the risk of prostate cancer in current studies.
We need better designed studies to find out more about the potential link.
And remember, eating or drinking some dairy has health benefits. And the NHS Eatwell guide recommends having it as part of a healthy, balanced diet. Try to pick dairy or dairy alternative products that are low in fat and sugar.
Read more about recommended daily dairy portions below.
Breast cancer risk and dairy
There is no good, consistent evidence that milk and dairy products can cause breast cancer.
Some studies have found that dairy might increase the risk of breast cancer. Whilst others have found it may decrease breast cancer risk. We need more high-quality studies to understand whether there is a link.
The best thing you can do is to eat a healthy, balanced diet.
How much dairy should I eat or drink?
Milk and dairy are good sources of calcium and protein. The NHS Eatwell Guide recommends having some dairy or dairy alternatives as part of a healthy, balanced diet.
The amount of fat (particularly saturated fat), salt and sugar in dairy products can vary. Where possible choose low-sugar and reduced-fat products as they are healthier dairy options.
- 1% fat milk (red capped in supermarkets)
- Reduced-fat cheese
- Lower-fat spreads
- Plain, low-fat yoghurt (watch out for low-fat products high in added sugar, plain yoghurt is usually a good choice)
Not everyone can eat dairy and some people choose not to. Dairy alternatives are also good sources of calcium. For example, unsweetened, calcium-fortified soya versions of milk, cheese and yoghurt.
The British Dietetic Association recommends you aim for 3 portions of dairy foods a day.
Examples of adult portions of dairy include:
- A glass of 1% fat milk
- A 150g pot of plain, low-fat yogurt
- A matchbox-size piece of cheese (30g)
Remember, when it comes to cancer risk, your overall diet is much more important than individual foods.
What you eat day to day can reduce your cancer risk.
Should I be worried about casein and hormones in milk?
Casein is the main protein in milk. There is no strong evidence to show this causes cancer in humans.
Dairy products do contain some hormones. But the amount is very small compared to what the body makes naturally. There is no strong evidence to show that hormones in milk could go on to cause cancer.
Some countries use a hormone called bovine somatotrophin (BST) to speed up or increase the production of milk or meat. But in the UK and the rest of Europe, there is a ban on farmers using this hormone. This ban is on animal welfare grounds, not because there is any proven effect on human health.
The Food Standards Agency regulates the content of dairy products, including milk. This set of standards makes sure these products are safe to eat and drink.
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.
World Cancer Research Fund/American Institute for Cancer Research. Continuous Update Project Expert Report 2018. Diet, nutrition, physical activity and colorectal cancer. https://www.wcrf.org/sites/default/files/Colorectal-cancer-report.pdf
NHS. The Eatwell Guide. 2020. https://www.nhs.uk/live-well/eat-well/the-eatwell-guide/
Public Health England. Government recommendations for energy and nutrients for males and females aged 1–18 years and 19+ years. https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/618167/government_dietary_recommendations.pdf