Calcium in dairy products may lower risk for colorectal cancer
Key takeaways:
- Consumption of 300 mg of calcium daily reduced the risk for colorectal cancer by 17%.
- Both alcohol and red and processed meat intake increased colorectal cancer risk.
Increased intake of calcium and dairy reduced the risk for colorectal cancer, a prospective cohort analysis published in Nature Communications revealed.
In comparison, the consumption of other certain foods and drinks, particularly alcohol, increased this risk.
“This is the most comprehensive single study ever conducted into the relationship between diet and bowel cancer, and it highlights the potential role of calcium in the development of this disease,” Keren Papier, a senior nutritional epidemiologist at Oxford Population Health, said in a press release. “Further research is needed to understand the potential health impacts of increasing calcium in different populations.”
In the study, Papier and colleagues analyzed associations between 97 dietary products and nutrients and the risks for colorectal and bowel cancer in a cohort of 542,778 participants from the Million Women Study.
The analysis showed 12,251 cases of colorectal cancer in the sample during a follow-up period of 16.6 years.
The researchers found that 300 mg of calcium daily corresponded with a 17% decrease in the risk for colorectal cancer (RR = 0.83; 95% CI, 0.77-0.89)
The results also showed an inverse association between yogurt, riboflavin, magnesium, whole grains, folate, carbohydrates, fiber, total sugars, vitamin C, phosphorus, dairy milk, breakfast cereal, fruit and potassium and the risk for colorectal cancer, but many of these links’ magnitudes were relatively small and “may have been influenced by residual confounding by lifestyle and/or other dietary factors,” Papier and colleagues noted.
They added that the effects of calcium from nondairy and dairy sources were similar, which shows that the benefits achieved from dairy milk and other dairy-related food sources “are likely largely or wholly driven by calcium intake.”
“The probable protective role of calcium may relate to its ability to bind to bile acids and free fatty acids in the colonic lumen, thereby lowering their potentially carcinogenic effects,” they wrote.
Genetically predicted milk intake of 200 g a day reduced the risks for rectal (RR = 0.49; 95% CI, 0.31-0.67), colon (RR = 0.6; 95% CI, 0.43-0.77) and colorectal (RR = 0.6; 95% CI, 0.46-0.74) cancers, associations “likely to also reflect calcium intake,” Papier and colleagues wrote.
Meanwhile, intake of 20 g of alcohol daily increased the risk for bowel cancer by 15% (RR = 1.15; 95% CI, 1.09-1.2), a finding consistent with recent research that positively tied moderate alcohol consumption to some cancers.
The results further showed that daily consumption of 30 g of red and processed meat was associated with an 8% increased risk for colorectal cancer (RR = 1.08; 95% CI, 1.03-1.12).
The researchers noted that because most of the sample was middle- or older aged woman of European descent from the United Kingdom, the results may not be generalizable to other populations or to populations where a large majority cannot digest lactose.
“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,” Sophia Lowes, a senior health information manager at Cancer Research U.K., said in the release. “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.”
References:
- Increased calcium and dairy intake lower risk of bowel cancer by nearly a fifth. Available at: https://www.ceu.ox.ac.uk/news/increased-calcium-and-dairy-intake-lower-risk-of-bowel-cancer-by-nearly-a-fifth. Published Jan. 8, 2025. Accessed Jan. 23, 2025.
- Papier K, et al. Nat Commun. 2025;doi:10.1038/s41467-024-55219-5.