Specific dairy foods may influence breast cancer risk in women, although risk varies by the source of the dairy product, according to a study published online ahead of print in the journal Current Developments in Nutrition.

Researchers at Roswell Park Cancer Institute report that while high overall consumption of dairy products, and in particular of yogurt, is linked to a lower risk for breast cancer, high intake of American, cheddar and cream cheeses was associated with a slightly increased risk for breast cancer.

The case–control study examined the association between the types and quantity of dairy foods consumed among 1,941 women diagnosed with breast cancer and 1,237 control participants in the Roswell Park Data Bank and BioRepository between 2003 and 2014. Participants’ usual intake of dairy foods was identified using a self–administered food frequency questionnaire and grouped into monthly intakes of total dairy, milk, yogurt, low–fat cheese, other cheese and sweet dairy products. The study adjusted for age, race, body–mass index, menopausal status, energy intake, type of milk usually consumed, cigarette smoking status and family history of breast cancer.

“Dairy foods are complex mixtures of nutrients and non–nutrient substances that could be negatively as well as positively associated with breast cancer risk. Future studies are needed to confirm the protective potential of yogurt in this type of cancer,” says the lead author of the study, Susan McCann, PhD, RD, Professor of Oncology in the Department of Cancer Prevention and Control at Roswell Park.

“This study of the differences among women and their consumption of dairy products offers significant new understanding into the potential risk factors associated with breast cancer,” says senior author Christine Ambrosone, PhD, Senior Vice President for Population Sciences and Chair of the Department of Cancer Prevention and Control. “While diet is thought to be responsible for 30% of all cancers, we hope that further research will help us to more fully understand which food products are most valuable in terms of reducing risk for this disease.”