Prospective study on milk products, calcium and cancers of the colon and rectum

Objective: To study the relationship between consumption of milk and milk p roducts, calcium, lactose and vitamin D and occurrence of colorectal cancer s. Design: Prospective cohort study. Subjects: A total of 9959 men and women aged 15 y or older without history of cancer at baseline. During a 24y follow-up, 72 new cancers of the large bowel (38 in the colon and 34 in the rectum) were detected. Results: Consumption of milk and total milk products was suggested to be in versely related to colon cancer incidence, whereas no similar association w as seen for rectal cancer. The relative risk between the highest and lowest quartiles of intake adjusted for potential confounding factors was 0.46 (9 5% confidence interval 0.14-1.46, P for trend 0.09) for milk and 0.37 (95% CI = 0.12 - 1.39, P for trend 0.06) for total milk products. Lactose intake showed a similar inverse relationship with colon cancer: the relative risk was 0.31 (95% CI = 0.08 - 1.15, P for trend 0.03). Intake of vitamin D or total dietary calcium was not significantly related to colorectal cancer ri sk, whereas calcium provided by fermented milk products was associated with increased colorectal cancer incidence; in the highest quartile the multiva riate adjusted relative risk for colorectal cancer was 2.07 (95% CI = 1.00 - 4.28). Conclusions: Our results indicate that individuals showing high consumption of milk have a potentially reduced risk of colon cancer; however, the asso ciation does not appear to be due to intake of calcium, vitamin D, or to sp ecific effects of fermented milk. Sponsorship: This study was supported by a grant from the Swedish Cancer Fo undation.