It’s long been known that milk is good for your teeth and bones.
Now, experts have discovered that having a glass a day can also slash your risk of bowel cancer by nearly a fifth, according to a study of more than half-a-million women.
An additional 300mg of calcium a day – about the amount in a large glass of milk – could be linked to a 17 per cent decrease in the risk of bowel cancer, or colon cancer, as it’s known in the US.
Scientists analysed dietary data from more than 542,000 women to investigate the link between 97 products and nutrients and the chances of someone developing bowel cancer.
The findings showed that food and drink rich in calcium such as milk and yoghurt were linked to a lower risk of a bowel cancer diagnosis over 16 years.
Calcium was found to have a similar effect from both dairy and non-dairy sources, suggesting it was the main factor responsible for cutting risk.
However, eating lots of cheese or ice cream did not make a difference, the team discovered.
The findings, published in the journal Nature Communications, also reinforced the clear link between alcohol consumption and a higher bowel cancer risk.
Calcium, a mineral in milk, was thought to be responsible for the reduced bowel cancer risk in dairy eaters.
Young, seemingly healthy people like Carly Barrett, from Kentucky, are increasingly falling victim to colon cancer. She was diagnosed at age 24 after detecting blood in her stool and suffering from abdominal pain
Drinking an extra 20g of alcohol a day – equivalent to a large glass of wine – was found to cause a 15 per cent increase in risk across the cohort.
Red and processed meat were among the other dietary foods associated with higher chances of bowel cancer, with 30g more per day linked to an 8 per cent increase in risk.
There are about 44,000 cases of bowel cancer every year in the UK and 150,000 in the US, making it the fourth most common cancer in both countries.
But cases are rising in young people, an alarming trend linked to modern diets, chemical exposure and sedentary lifestyles.
Dr Keren Papier, lead researcher and senior nutritional epidemiologist at Oxford Population Health, said: ‘This is the most comprehensive single study ever conducted into the relationship between diet and bowel cancer, and it highlights the protective role of calcium in the development of this disease.
‘Further research is needed to understand the health impacts of increasing calcium in different populations.’
The team said the protective role of calcium may come from its ability to bind to bile acids and free fatty acids in the colon, therefore lowering their potentially cancer-causing effects.
Sophia Lowes, senior health information manager at Cancer Research UK, who funded the study, said: ‘Bowel cancer is one of the most common cancers affecting people in the UK, which is why it’s so vital that we know how to prevent it.
‘Maintaining a healthy, balanced diet, alongside keeping a healthy weight and stopping smoking, 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.
‘We look forward to further research, including into the effects of specific ingredients like calcium, to ensure fewer people are impacted by this devastating disease.’
American Raquel (left) was 28 when doctors diagnosed her with stage four colon cancer. Evan White (right) was diagnosed with colon cancer at 24. He died four years later, just weeks before his wedding
Independent experts have welcomed what they called a ‘well conducted analysis’ adding it could have implications for many women.
Professor Andrew Prentice, an expert in nutrition at the London School of Hygiene & Tropical Medicine said: ‘Results emphasise that milk consumption is particularly beneficial and show evidence that this effect may be largely due to the calcium in milk, begging the question as to whether calcium supplements might be protective.
‘The jury is out on this but as a nutritionist I shall continue to take my calcium from milk and dairy foods which are rich in so many nutrients.’
Professor Tom Sanders an expert in nutrition at King’s College London said the results backed up previous research showing dairy products could protect against cancer, though the mechanism of how exactly this worked was still unknown.
‘One theory is that the calcium may bind to free bile acids in the gut preventing the harmful effects of free bile acids on gut mucosa,’ he said.
However, Professor Ian Givens, an expert in nutrition at the University of Reading, said the findings were concerning given data that suggests British women don’t consume enough dairy, in theory increasing their risk of cancer.
‘What’s particularly concerning is that many UK women, especially younger age groups, are consuming less dairy and have calcium intakes below recommended levels,’ he said.
‘Combined with other large-scale research, these findings make a strong case for maintaining adequate dairy consumption as part of a balanced diet.’
