NAIROBI, Kenya – A long-term study of over half a million UK women has proved that dietary calcium reduces the risk of colorectal cancer, one of the most common cancers worldwide.
The research, conducted by Dr. Sheena Meredithis and funded by Cancer Research UK (CRUK), tracked participants for nearly 17 years and found that higher calcium intake was associated with a 17% reduction in relative risk (RR) of developing the disease.
Comprehensive Study of Dietary Factors
The research, led by the University of Oxford and published in Nature Communications, monitored 97 dietary factors in 542,778 women from 2001, with detailed dietary questionnaires and follow-up assessments.
During the study period, 12,251 participants were diagnosed with colorectal cancer.
Analysis revealed that higher calcium intake, equivalent to about a large glass of milk daily, had the strongest protective association against the cancer.
Calcium’s Independent Protective Role
Interestingly, the protective benefits of calcium were found to be independent of dairy milk intake, suggesting calcium itself plays a key role.
Six other calcium-related dietary factors, including yogurt, riboflavin, and magnesium, were also linked to lower cancer risk, though to a lesser extent.
Dr. Meredithis and her team emphasized that while dairy products contribute to cancer prevention, calcium is the primary protective component.
Confirming Risk Factors: Alcohol and Processed Meats
Consistent with previous research, the study also confirmed that alcohol and processed meats increase colorectal cancer risk.
A daily increase of 20 grams of alcohol raised RR by 15%, while each additional 30 grams of red and processed meat correlated with an 8% increase.
Commenting on the findings, Professor Tom Sanders from King’s College London suggested that calcium might protect the gut by binding to harmful bile acids.
However, Dr. David Nunan of the University of Oxford urged caution, highlighting the limitations of observational studies and the need for more robust evidence from randomized controlled trials.
