Press release: New Study Associates Intake Of Dairy Milk With Greater Risk Of Breast Cancer, Loma Linda University, 25 February 2020

Study: Dairy, Soy, And Risk Of Breast Cancer: Those Confounded Milks, International Journal of Epidemiology, 25 February 2020

Excerpts from press release:

Intake of dairy milk is associated with a greater risk of breast cancer in women, according to a new study conducted by researchers at Loma Linda University Health.

“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%,” [first author of the paper, Gary E. Fraser, MBChB, PhD] said. “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%.”

Current U.S. Dietary guidelines recommend three cups of milk per day. “Evidence from this study suggests that people should view that recommendation with caution,” Fraser said.

“[Frazer said] 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.”

A hazardous effect of dairy is consistent with the recent AHS-2 report suggesting that vegans but not lacto-ovo-vegetarians experienced less breast cancer than non-vegetarians.

Fraser said the possible reasons for these associations between breast cancer and dairy milk may be the sex hormone content of dairy milk, as the cows are of course lactating, and often about 75% of the dairy herd is pregnant. Breast cancer in women is a hormone-responsive cancer. Further, intake of dairy and other animal proteins in some reports is also associated with higher blood levels of a hormone, insulin-like growth factor-1 (IGF-1), which is thought to promote certain cancers.

How does the USDA get away with telling women to consume 3 cups of milk a day when research indicates it increases breast cancer risk?