August 10, 2005 – Before menopause, calcium and vitamin D may help prevent breast cancer. At least that’s what the results of an epidemiological survey indicate.1 conducted in Quebec among 777 perimenopausal women and 783 postmenopausal women.
For each of the participants, the researchers assessed the intake of calcium and vitamin D, either from a supplement or from a food source. They found that in perimenopausal women, breast density was associated with the consumption of these two nutrients: the higher the intake of calcium and vitamin D, the lower the breast density. This link could not be established in postmenopausal women.
Breast density is considered a reliable measure of the risk of contracting breast cancer; the higher it is, the greater the risk.
The results of the survey indicate that a daily intake of 1000 mg of calcium and 400 IU (10 µg) of vitamin D is linked to an 8.5% reduction in breast density. It should be noted by way of comparison that tamoxifen, a synthetic anti-estrogen used in prevention in high-risk women, causes a 6.4% decrease in breast density after 4 and a half years.
“If our data is confirmed during clinical trials, this will really be a find that could have a significant impact on public health,” says one of the study’s authors, Dr Jacques Brisson of the Population Health Research Unit of the Hôpital Saint-Sacrement in Quebec. Note that an epidemiological investigation does not clearly demonstrate the effectiveness of a nutrient in preventing disease. It only provides data that can guide clinical research. The team of Dr Brisson is also in the process of preparing a clinical trial to verify the effect of these two nutrients in preventing breast cancer.
Food sources of calcium and vitamin D include milk and fatty fish. To obtain the required amounts (approximately 1000 mg of calcium and 400 IU of vitamin D), for example, two to three glasses of milk (250 ml each) would have to be consumed per day or 150 g of canned sardines.
Pierre Lefrançois – Proteus Network
According to La Presse.
1. Berube S, Diorio C, Masse B, et al.Vitamin D and calcium intakes from food or supplements and mammographic breast density.Cancer Epidemiol Biomarkers Prev. 2005 Jul; 14 (7): 1653-9.