Study: Dairy Products Cut Breast Cancer Risk in Premenopausal Women

Premenopausal women who consume a lot of dairy foods appear to have a reduced risk of developing breast cancer, according to Harvard researchers.

However, researchers found no link between the intake of dairy products and breast cancer in postmenopausal women.

Prior research suggests that calcium and vitamin D, found at high levels in dairy products, might reduce the development of breast cancer. However, study results have been inconsistent.

Researchers examined data from a large, long-term study to evaluate whether high intake of dairy products, calcium or vitamin D is linked with a reduced risk of breast cancer.

A total of 88,691 women were given a food-frequency questionnaire in 1980 and were followed until May 1996. Dietary information was collected in 1980 and updated in 1984, 1986, 1990 and 1994. A total of 3,482 women (827 premenopausal, 2,345 postmenopausal, 310 uncertain menopausal status) women developed invasive breast cancer.

In premenopausal women, consumption of dairy products, especially of low-fat dairy foods and skim/low fat milk, was linked with a reduced risk of breast cancer, the researchers reported in the Journal of the National Cancer Institute.

Dairy calcium, total vitamin D and lactose also were associated with a reduced risk of breast cancer in premenopausal women. By taking into account calcium and vitamin D supplements taken by the women, the link with calcium was due primarily to dairy sources whereas the link with vitamin D may be independent of dairy intake.

Other sources: Journal of the National Cancer Institute