Calcium Intake and Breast Cancer
One of the myths that refuses to die and continues to float around on the internet is related to dairy and cancer in general, breast cancer in specific. I often talk with women who are worried about eating anything containing calcium (or sugar, that's another one) because of things they have been told about association with cancer. I was, therefore, delighted to see this study from Norway about dairy intake (milk and cheese, although one would assume that yogurt etc would be the same) not being associated with a higher risk of breast cancer. Matter of fact, premenopausal women who ate the most white cheese had a lower risk of developing breast cancer than women who ate less. One can extrapolate from this finding to believe that calcium would also not be associated with a higher risk of breast cancer recurrence.
Bring on the blue cheese, the brie, the sharp cheddar, the livarot....
Dairy consumption and calcium intake and risk of breast cancer in a
prospective cohort: The Norwegian Women and Cancer study
Anette Hjartåker1 , Magne Thoresen2, Dagrun Engeset3 and Eiliv Lund3
(1) Department of Etiological Research, Cancer Registry of Norway, Post box 5313, Majorstua, N-0304 Oslo, Norway
(2) Department of Biostatistics, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
(3) Institute of Community Medicine, University of Tromsø, Tromsø, Norway
To study the association between consumption of dairy products and calcium intake and risk of breast cancer risk according to menopausal status.
In a population-based prospective cohort study of 64,904 Norwegian women followed from 1996/1999 through 2006, we examined total dairy consumption and consumption of various dairy products in relation to pre- and postmenopausal breast cancer risk. We also examined breast
cancer in relation to calcium intake and to milk consumption during childhood and performed additional analyses corrected for measurement errors in the dietary data. In total, 218 premenopausal and 1,189 postmenopausal incident breast cancer cases were diagnosed during
Total dairy, adult, and childhood milk consumption was not associated with either pre- or postmenopausal breast cancer risk. Premenopausal women with the highest consumption of white cheese had half the risk of breast cancer compared to those with the lowest consumption (hazard
rate ratio in the 4th quartile vs. the 1st quartile 0.50, 95% confidence interval 0.29-0.87). Total calcium intake tended to be inversely related to premenopausal (hazard rate ratio in the 4th
quartile vs. the 1st quartile 0.65, 95% confidence interval 0.39-1.08) and postmenopausal breast cancer (hazard rate ratio in the 4th quartile vs. the 1st quartile 0.85, 95% confidence interval 0.70-1.04). Correcting for measurement errors did not alter the results substantially, nor did
exclusion of early cancer cases.
Dairy consumption is not strongly related to breast cancer risk in this prospective study. A non- significant negative association between calcium intake and breast cancer risk was seen, particularly among premenopausal women.