Intake of dairy milk is linked to a high risk of breast cancer in women, according to a study published in the International Journal of Epidemiology.
Researchers at Loma Linda University Health revealed that consuming relatively moderate amounts of dairy milk can contribute to women's risk of breast cancer. It may rise to 80% depending on the amount women consumed.
Based on the study titled “Dairy, soy and risk of breast cancer: Those confounded milks,” there were no solid associations between soy products and breast cancer, independent of dairy.
The findings "fairly strong evidence that either dairy milk or some other factor closely related to drinking dairy milk is a cause of breast cancer in women,” said the study author, Gary E. Fraser, MBChB, PhD.
"Consuming as little as 1/4 to 1/3 cup of dairy milk per day was associated with an increased risk of breast cancer of 30%," Fraser explained, adding, "By drinking up to one cup per day, the associated risk went up to 50%, and for those drinking two to three cups per day, the risk increased further to 70% to 80%."
He emphasized that the results showed minimal variation when it comes to the intake of full fat compared to reduced or nonfat milks. No important associations were found with cheese and yogurt.
"Evidence from this study suggests that people should view that recommendation with caution," Fraser said.
"However," he said, "dairy foods, especially milk, were associated with increased risk, and the data predicted a marked reduction in risk associated with substituting soymilk for dairy milk. This raises the possibility that dairy-alternate milks may be an optimal choice."
Fraser believes that the link could be the sex hormone content of dairy milk. "Dairy milk does have some positive nutritional qualities," he said, "but these need to be balanced against other possible, less helpful effects. This work suggests the urgent need for further research."
