Cancer du colon

Colon cancer risk? Milk to the rescue!

The exceptionally high consumption of dairy products, particularly milk, by the people of Finland is lucky for all of us! Why? Because it's led to a new understanding of calcium's role in helping to prevent colorectal cancer. One of the leading causes of mortality in the Western world, colorectal cancer has long been known to be modulated through diet and nutrition.1,2 Although various studies have examined the relationship between calcium and colorectal cancer with varying results, it's the high consumption of milk in Finland that made it possible for investigators to understand that it takes calcium intakes of 1000 mg/day to attenuate the risk.3 And that makes for news with a double-edged sword. The good news is that number reflects the new recommendations for calcium intake (1,000 mg/day for adults 19 to 50 years of age and 1,200 mg for those over 50); the bad news is that most Canadians, with the possible exception of males aged 18 to 34, fail to meet these requirements.4,5 Interestingly, no associations were found in the Finnish study between colorectal cancer and intakes of fat (or specific fatty acids) or fibre, or consumption of meat, vegetables, or whole grain cereals.

There is both biochemical and biological evidence that exposure to calcium and/or vitamin D reduces the oncogenic properties of colon cancer cells,2 probably due to their ability to lower aqueous fecal concentrations of bile acids and fatty acids.1,2 And calcium-rich dairy foods have been shown to significantly improve several parameters of cell proliferation and to effectively alter biomarkers of risk for colon cancer from a high risk to lower risk levels.1,2

References: 1. Lipkin bt et al. 1999. Dietary factors in human colorectal cancer. Annu Rev Nutr 19:345-586. 2. Holt PR. 1999. Dairy foods and prevention of colon cancer: human studies. J Am Cofi Nutr 18:3795-3915. 3. Pietinen P et al. 1999. Diet and risk of colorectal cancer in a cohort of Finnish men. Cancer Causes and Control 10:387-396. 4. Bertrand L. 1995. Les Quebecoises ei les Quebecois mangent-ils mieux? Rapport de L'enquete quebecoise sur la nutrition 1990. Gouvernement du Quebec, Sante Quebec. 5. Nova Scotia Heart Health Program. 1993. The Report of the Neva Scotia Nutrition Surrey, Nova Scotia Department of Health, Halifax, N.S. 6. Heaney RP. 2000. Calcium, dairy products and osteoporosis. J Am Col! Nutr 19:835-995. 7. Barger-Lux MJ et al. 1992. Nutritional correlates of low calcium intake. Clin in Applied Nut, 239-44. S. Devine A et al. 1996. Nutritional effect of calcium supplementation by skim milk powder or calcium tablets on total nutrient intake in postmenopausal women. Am J Clin Nutr 64. i 31-737 9. Gueguen Land Pointillart A. 2000. The bioavailability of dietary calcium. J Am Coll Nutr 19(Suppl!:1195-1365.

Helen Bishop MacDonald, RD, MSc, FDC

Director, Nutrition, Dairy Bureau of Canada