One simple lifestyle change can lower your risk of bowel cancer by 17%, new study reveals

As more research on the link between our diet and cancer becomes available, what's clear is that simple lifestyle changes make the biggest difference to our health - and a new study has just added another one to the list.

The latest study on the link between what we eat and cancer risk comes from the University of Oxford and it suggests that simply drinking a glass of milk every day can do more than help you maintain strong bones - it could be the way to lower your risk of bowel cancer.

Bowel cancer is the third most common cancer diagnosed in women, with almost 20,000 new cases every year, according to Cancer Research UK. Concerningly, cases in England are rising in those under 50 without a clear reason why - although it's still most commonly diagnosed in those over 85.

The study, funded by Cancer Research UK and published in Nature Communications, found that having an additional 300mg of calcium every day - equal to a glass of milk - can decrease the risk of colorectal cancers by 17%. That's on top of the 700mg already recommended by the NHS.

"It highlights the potential protective role of dairy, largely due to calcium, in the development of bowel cancer," said Dr Keren Papier, lead researcher at the University of Oxford.

Researchers collected data on the dietary habits and bowel cancer risk of more than half a million women over 16 years old. They focused on the impact of 97 different food products and nutrients, specifically calcium-rich foods, leafy greens, fortified milk alternatives, and processed meat.

Although the study also found that these other foods - including breakfast cereals, fruits, whole grains, carbohydrates, fibre, sugars, folate, and vitamin C - made a difference, they only offered a slight risk reduction.

Dr Papier revealed why the link between dairy specifically and a lower risk of bowel cancer might exist. "We have some idea why calcium has this effect. It's suggested that calcium might protect against bowel cancer by binding to bile acids and free fatty acids to form a type of harmless 'soap', which stops them from damaging the lining of the gut," she said.

The easiest way to fit an extra 300mg of calcium is to drink a large glass of dairy milk every day. However, adding other foods rich in calcium can help too.

Foods high in calcium

According to the NHS and the Royal Osteoporosis Society, the following foods are also rich in calcium. These can contribute to the additional 300mg suggestion per day:

• Dairy foods, such as milk, cheese, and yoghurt
• Green leafy vegetables, particularly kale
• Fortified cereal products, including cereal and bread
• Fish with bones, such as sardines and pilchards
• Salmon
• Baked beans
• Sausages - vegetarian or pork varieties
• Sesame seeds
• Porridge with semi-skimmed milk
• Tofu
• Rice pudding

What else did the study find?

The study also found links between alcohol and processed meat and a higher risk of bowel cancer. They discovered that drinking an additional large glass of wine (250ml) per day increases the risk by 15% and eating more red and processed meat, including ham, increases the risk by 8%.

While this is nothing new - several studies, including those by Oxford Population Health and the University of Bergen - have pointed to the benefits of giving up alcohol and eating less ultra-processed food for our health, this new study puts particular percentages on the risk.

The study also found that yogurt, riboflavin (a type of vitamin B), phosphorus, magnesium, and potassium, were all associated with a lower risk of colorectal cancer.

It highlights just how important a balanced diet, with a low alcohol intake and processed food, is for our long-term health and wellbeing.

A note on the study

While this study is a promising step forward, using a large dataset of women to demonstrate the impressive benefits of including more calcium in a balanced diet, it's tricky to say what these percentages mean in 'real life'. Everyone's risk of bowel cancer is slightly different depending on a variety of factors, including lifestyle habits (such as smoking, drinking, exercise, sleep, and stress) and genetics.

The results of the study also point out that women who developed colorectal cancer tended to be older, taller, and have more family history of bowel cancer, with more "adverse health behaviours" compared to participants overall.

A higher calcium intake may also not be suitable for everyone, so if you have concerns about your risk of bowel cancer or steps you can take to lessen the potential risk, speak to your doctor.