A daily glass of milk could reduce your risk of colorectal cancer by up to 17%, according to extensive research spanning over half a million participants.
At a Glance
- A landmark study of 542,778 women found calcium and dairy products are linked to decreased colorectal cancer risk
- Consuming 300mg of calcium daily (about one large glass of milk) may reduce bowel cancer risk by 17%
- Milk consumption is associated with a 14% lower risk per 200g/day, with Mendelian randomization studies showing even stronger protection
- Processed meats and alcohol increase colorectal cancer risk, while high-fiber foods and dairy appear protective
- Colorectal cancer is the fourth most common cancer in the UK, with over 44,100 cases annually, but more than half are preventable
The Dairy-Cancer Connection
New research has revealed promising evidence that dairy consumption, particularly milk, may help reduce the risk of colorectal cancer. The largest single study on diet and bowel cancer to date, conducted by the University of Oxford and funded by Cancer Research UK, analyzed data from over 500,000 women followed for 16 years. Researchers examined 97 dietary factors and identified 17 with significant associations to colorectal cancer risk, with calcium and dairy products emerging as potentially protective elements.
The findings showed that an additional 300mg of calcium daily—equivalent to one large glass of milk—correlated with a 17% lower risk of developing colorectal cancer. Further strengthening these results, Mendelian randomization analysis, which helps establish causality by examining genetic variations, demonstrated even more substantial protection: a 40% reduction in colorectal and colon cancer risk and a 51% reduction in rectal cancer risk with 200g/day of milk consumption.
— Norgen Biotek Corp (@NorgenBiotek) February 26, 2025
Biological Mechanisms Behind Protection
Scientists believe they understand how calcium in dairy products may offer protection against colorectal cancer. Calcium appears to bind to potentially harmful substances in the digestive tract, preventing them from damaging the cells lining the colon. This includes neutralizing bile acids and free fatty acids that could otherwise promote cancer development through irritation and inflammation of the intestinal lining.
The protective effect appears to be strongest with milk consumption, while evidence regarding other dairy products like cheese has been more inconsistent. Several meta-analyses have confirmed this pattern, with one comprehensive review finding that high total dairy consumption was associated with a 21% reduced risk of colorectal cancer incidence and a striking 29% lower risk of colorectal cancer mortality.
To reduce cancer risk we recommend limiting red meat and processed meat consumption! 🥩
🥓 This is as there is strong evidence that consuming red and processed #meat increases the risk of #colorectalcancer.
Read more here: 🔗https://t.co/ZhwSb3CMfK pic.twitter.com/J2rAZNriWZ— WCRF International (@wcrfint) March 1, 2020
Beyond Dairy: Other Dietary Factors
While dairy consumption shows protective potential, the research also identified other dietary factors influencing colorectal cancer risk. Processed and red meat consumption was linked to an increased risk of 8% per 30g daily intake. Similarly, alcohol consumption raised risk by approximately 15% per 20 grams consumed daily—roughly equivalent to two standard drinks. Conversely, foods high in fiber, vitamin C, and folate demonstrated inverse relationships with colorectal cancer risk.
This research highlights the importance of a comprehensive approach to colorectal cancer prevention. Beyond dairy consumption, maintaining a healthy weight, staying physically active, limiting alcohol intake, and consuming a balanced diet rich in protective nutrients appear to offer the best protection. With colorectal cancer being the fourth most common cancer in the UK and more than half of cases considered preventable, these dietary insights provide valuable guidance for public health strategies.
Different Dairy Products, Different Effects
The protective effect of dairy appears to vary by product type. While milk consistently shows the strongest inverse association with colorectal cancer risk, the evidence for cheese and other dairy products has been mixed. Some studies suggest cheese may offer protection specifically against proximal colon cancer, but these findings have been less consistent than those for milk. Research also indicates that low-fat dairy options might provide greater protective benefits than their full-fat counterparts.
It’s worth noting that dairy consumption has shown varying relationships with different cancer types. A major study in Chinese populations found increased risks for liver and female breast cancer with higher dairy intake. These contrasting findings highlight the complexity of diet-cancer relationships and emphasize the need for personalized nutrition advice that considers individual health profiles, genetic predispositions, and cultural dietary patterns.
Sources:
https://www.eatingwell.com/colorectal-cancer-milk-study-8775172
