Can milk and dairy products cause cancer?

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.

Examples include:

• 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.