Bowel cancer symptoms: signs to look out for as new study reveals a glass of milk a day may reduce risk

• New research funded by Cancer Research UK has found that drinking a glass of milk a day could reduce the risk of bowel cancer by 17%.
• It found that eating foods rich in calcium, like milk and yoghurt, was linked to a lower risk of developing bowel cancer.
• There are around 44,100 cases of bowel cancer every year in the UK.

New research funded by Cancer Research UK has found that consuming a glass of milk a day could lower your risk of bowel cancer by nearly a fifth.

The study found that consuming an additional 300mg of calcium - about the amount in a large glass of milk - a day could be linked to decreasing the risk of bowel cancer by 17%.

Bowel cancer is the fourth most common cancer in the UK, with around 44,100 cases every year, with more than five in 10 of these cases preventable.

The researchers from the University of Oxford used data from more than 500,000 women to investigate the link between 97 dietary products and bowel cancer risk over an average time of 16 years.

What are the symptoms of bowel cancer?

Bowel cancer is the fourth most common cancer in the UK with around 44,100 cases every year, but more than five in 10 cases are preventable and it’s important to be aware of symptoms so that you can get an early diagnosis.

The symptoms of bowel cancer, according to Bowel Cancer UK can include:

• bleeding from your bottom
• blood in your poo
• a change in your pooing habits, such as going more or less often, or diarrhoea or constipation that might come and go
• losing weight but you’re not sure why
• feeling very tired all the time but you’re not sure why
• a pain or lump in your tummy

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What does the study say?

The new research which was funded by Cancer Research UK, with researchers from the University of Oxford using data from more than 500,000 women to investigate the link between 97 dietary products and nutrients and bowel cancer risk over an average time of 16 years.

The study found that eating foods rich in calcium, such as milk and yoghurt, was linked to a lower risk of developing bowel cancer, this was also the case for eating dark leafy green vegetables which also contain calcium. Highlighting that calcium is likely an important factor in helping reduce the risk of bowel cancer.

Dr Keren Papier, lead researcher of the study said: “This is the most comprehensive single study ever conducted into the relationship between diet and bowel cancer, and it highlights the potential protective role of calcium in the development of this disease.”

Dr Papier continued: “We have some idea on 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 a harmless ‘soap’, which stops them from damaging the lining of our gut.

“This ‘soap’ effect helps these bile and fatty acids to be swept out of the gut like a ‘spring clean’ so they can’t build up and so are less likely to cause damage.”

How can I reduce the risk of bowel cancer?

The study has also confirmed how our diet can influence our risks in a negative way. It found there was a clear link between alcohol consumption and a higher risk of bowel cancer, drinking an additional 20g of alcohol a day, which is the equivalent to a large glass of wine, was found to increase bowel cancer risk by 15%.

Sophia Lowes senior health information manager at Cancer Research UK said: “Alongside keeping a healthy weight and stopping smoking, maintaining a healthy, balanced diet is one of the best ways to lower your risk of bowel cancer.

“This includes cutting down on alcohol and red and processed meat, and eating lots of fruit, vegetables, and wholegrains. Dairy products like milk can also be part of a diet which reduces bowel cancer risk.”

As well as a glass of milk a day, the study found that non-dairy calcium sources, like dark green leafy vegetables, were linked to a lower risk of developing bowel cancer.

But according to Cancer Research UK, more research is needed into whether calcium supplements and calcium-fortified foods have the same effect on reducing bowel cancer risk.

“We couldn’t look at the association between taking calcium supplements and bowel cancer risk in this study,” Papier said.

"Given the widespread use of calcium supplements, future studies should investigate the role of calcium supplements in the prevention of bowel cancer in diverse populations.”

According to the NHS, good sources of calcium for vegans include:

• green, leafy vegetables such as broccoli, cabbage and okra
• fortified unsweetened soya pea and oat drinks
• calcium-set tofu
• sesame seeds and tahini
• pulses
• brown and white bread (in the UK, calcium is added to white and brown flour by law)
• dried fruit, such as raisins, prunes, figs and dried apricots

You can find out more information about bowel cancer at NHS.UK.