Low-fat dairy products may have a protective effect against breast cancer

Quebec City, November 27, 2019 – The consumption of low-fat dairy products may lower the risk of breast cancer, suggests a study published in the journal Anticancer Research by researchers from Université Laval and the CHU de Québec – Université Laval Research Centre. The protective effect on premenopausal women who consume at least two low-fat dairy products daily is similar to that of tamoxifen, a medication that reduces by 50% the risk of breast cancer in women likely to develop this disease.

Study authors Élisabeth Canitrot and Caroline Diorio reached these conclusions after studying the link between dairy product consumption and breast density. «Breast density reflects the relative abundance of glands and ducts in breast issue,» explained Caroline Diorio, a professor at Université Laval's Faculty of Medicine and principal investigator in the study. «This variable, which is measured during a mammogram, is an indicator of breast cancer risk. The denser the breast, the higher the risk of developing breast cancer.»
 
The researchers recruited 1,546 women, 775 of whom had not reached menopause when they came for a mammogram. The participants agreed to complete a food frequency questionnaire on their food and beverage consumption habits over the past year.

In premenopausal women, the consumption of 14 portions or more of low-fat dairy products per week is associated with 7% lower breast density than the consumption of fewer than 3 portions. «This is similar to the difference made by taking tamoxifen or having a child in your early 20s,» said Professor Diorio. «In both cases, the reduction in breast density reduces the risk of breast cancer by 50%.»

Conversely, the researchers observed a 4% higher breast density in women who consume larger quantities lot of high-fat dairy products compared to those who consume few or no high-fat dairy products.

«Our results suggest that regular consumption of low-fat dairy products may reduce the risk of breast cancer in premenopausal women,» said Professor Diorio. «However, it is too early to reach a definitive conclusion. We plan to carry out a larger prospective study soon to help clarify the question.»