By Lucy Williams, Ivanhoe Health Correspondent
ORLANDO, Fla. (Ivanhoe Newswire) -- If you're a woman, you may want to trade your burger for chicken or fish. Red meat consumption could put premenopausal women at risk for hormone receptor-positive breast cancer, reveals a new study.

"There was a two-fold increase for a woman who ate more than one-and-a-half servings of red meat per day compared to those who ate less than three servings of red meat per week," study author Eunyoung Cho, Sc.D., of Brigham and Women's Hospital and Harvard Medical School, told Ivanhoe.

Researchers reviewed diets of 90,659 premenopausal women who participated in the Nurses' Health Study II between 1991 and 2003. Participants completed food-frequency questionnaires and reported incidence of breast cancer. During the 12 years following the initial survey, women who reported the highest intake of red meat had the highest risk of developing hormone receptor-positive breast cancer. Breast cancer is classified as hormone receptor-positive if estrogen and progesterone can bind to surface proteins on the tumor.

Researchers are unable to precisely determine why red meat is linked to higher cancer incidence. Dr. Cho said several components of red meat could contribute to higher cancer risk, including:

Cancer-causing chemicals in cooked or processed red meat
Growth hormones given to cattle
Iron in red meat
Further research is needed to determine which, if any, of these are responsible for the increased risk of cancer.

Dr. Cho said women should not reduce red meat consumption simply because of this study, but there are other benefits of eating less red meat. "Red meat has been associated with other chronic diseases, including colorectal cancer, so I think our study provides another reason for a woman to reduce red meat intake," she said.

In the study, red meats included:

Whole beef products like steak
Whole pork products like pork loins
Bacon
Hotdogs
Hamburgers
Lamb
Other processed meats like lunch meats

SOURCE: Ivanhoe interview with Eunyoung Cho, Sc.D., Brigham and Women's Hospital and Harvard Medical School; Archives of Internal Medicine, 2006;166:2253-2259