High-fat Dairy May Increase Risk of Breast Cancer Death
Cancer patients who eat a daily serving or more of full-fat ice cream, cheese or milk or other high-fat foods increase their risk of dying from the disease compared to survivors who eat less, according to a new study published in the Journal of the National Cancer Institute.
The study is the first to examine the links between dairy and breast cancer mortality among cancer survivors. Previous research, including AICR's expert report and its continuous updates, has found no link between overall dairy consumption and risk of developing breast cancer.
The researchers followed almost 1,900 women diagnosed with early-stage invasive breast cancer who were enrolled in the Life After Cancer Epidemiology (LACE) study. All the participants filled out questionnaires about their diet and dairy intake at the start of the study; approximately 1,500 of the women completed a follow-up questionnaire six years later.
After an average of almost 12 years, women who consumed more than one serving a day of high-fat dairy foods had a 49 percent increased risk of dying from breast cancer during the course of the study when compared to women who consumed less than one-half serving a day, the study found. The researchers adjusted for smoking, BMI, physical activity, age, cancer stage, and meat, fiber and alcohol consumption.
Low-fat dairy and overall dairy intake did not link to breast cancer recurrence or breast cancer survival.
The authors suggested that estrogenic hormones in milk fat may be one reason that high fat dairy would link to poorer breast cancer outcomes. Exposure to estrogens is a major risk factor for breast cancer.
Source: Candyce H. Kroenke, Marilyn L. Kwan, Carol Sweeney, Adrienne Castillo and Bette J. Caan. "High- and Low-Fat Dairy Intake, Recurrence, and Mortality After Breast Cancer Diagnosis." JNCI J Natl Cancer Inst. First published online: March 14, 2013.