Consuming High-Fat Dairy May Increase Risk for Breast Cancer Death

Consuming full-fat dairy products after a diagnosis of breast cancer could worsen a patient's prognosis, according to a new study released Thursday.

The study, published Thursday in the Journal of the National Cancer Institute, is considered the first to look at the differences in high-fat and low-fat dairy intake following a breast cancer diagnosis on long-term survival.

This is the first-ever study to assess the association between low- and high-fat dairy and breast cancer, according to the authors, led by Candyce Kroenke, ScD, MPH, from Kaiser Permanente in Oakland, California.

"Consuming plant-based milks or nonfat dairy products may a reasonable approach for limiting risk of adverse outcomes," they write. In other words, breast cancer patients and survivors should consume rice, soy, or nonfat milk, cheese, yogurt, ice cream, butter, and other products.

The 12-year study looked at over 1,800 breast cancer survivors and discovered that consuming one or more portions of full-fat milk, cream, cheese or yogurt a day was associated with higher death rate.

Some other studies have linked dairy intake with hormone-linked cancers such as prostate and ovarian cancer.

The study's authors theorized estrogen levels are elevated in milk products produced in Western countries because dairy cows are often pregnant to maximize production, and pregnancy elevates their estrogen levels.

"It raises concerns that the way we produce milk should lead people to consider alternatives, especially if they have an elevated risk of breast cancer or if they have breast cancer and are trying to alter their lifestyles," Kroenke said.