Dairy foods raise risk of death for breast cancer survivors
Breast cancer survivors might want to think twice before consuming high-fat dairy products because a new study found that just half a serving per day increased the risk of dying from the disease.
According to the study of 1, 893 women, breast cancer survivors consuming as little as half a serving per day of high-fat dairy foods – such as butter, cheese and ice cream – had a 49 percent higher risk of dying from breast cancer than those who eat little or no high-fat dairy. However, consuming low-fat dairy had no bearing on recurrence or survival.
The research, published Thursday in the Journal of the National Cancer Institute, is the first-ever study to assess the association between low- and high-fat dairy and breast cancer, according to its authors, led by Candyce Kroenke, ScD, MPH, from Kaiser Permanente in Oakland, California.
The authors conducted this study to determine whether "dietary fat in dairy is a source of estrogenic hormones," which might be related to worse breast cancer survival.
In multivariable-adjusted analyses, Kroenke and colleagues found that overall dairy intake was unrelated to breast cancer-specific outcomes, although it was positively related to overall mortality.
In other words, as it pertains to breast cancer mortality, eating dairy is not the problem so much. It’s the type of dairy that matters. While low-fat dairy intake was unrelated to recurrence or survival, high-fat dairy intake was positively associated with outcomes – with those consuming larger amounts of high-fat dairy having higher breast cancer mortality.
The researchers therefore concluded that intake of high-fat dairy, but not low-fat dairy, was related to a higher risk of mortality after breast cancer diagnosis. However, they said, there are alternatives for women with breast cancer who are concerned about consuming high-fat dairy products.
"Consuming plant-based milks or nonfat dairy products may a reasonable approach for limiting risk of adverse outcomes," they wrote, suggesting that breast cancer patients and survivors should consume rice, soy, or nonfat milk, cheese, yogurt, ice cream, butter, and other products.
"In short, this study suggests that to improve survival, breast cancer survivors might shift away from high-fat to lower-fat dairy options, reduce high-fat dairy intake, and shift toward plant-based foods and milks (with little added sugar and salt)," Dr. Kroenke told Medscape Medical News in summing up the study.
As the authors also point out, the study is observational and therefore is not definitive. However, dairy products have been positively associated with other hormonal cancers – such as those of the prostate, endometrium and ovaries.
SOURCE: Journal of the National Cancer Institute. Published online March 14, 2013. Abstract