A new study finds that for young women, eating more red meat may increase the risk of a certain type of breast cancer, possibly due to hormones and other factors found in red meat, including beef.
The study data comes from a long-term investigation into the health of over 90,000 U.S. nurses. The results show that for relatively younger women, particularly premenopausal women, their red meat intake is linked to the risk of developing estrogen receptor-positive breast cancer.
Since hormone receptor-positive tumors contain a specific protein, the hormones estrogen and progesterone can accelerate tumor growth. The incidence of such tumors has been on the rise in the United States, especially among middle-aged women.
This study began in 1989, when the women's diets and other habits were surveyed. From 1991 to 2003, researchers conducted a long-term follow-up on these women's consumption of red meat. Only women who had not reached menopause and had no cancer were eligible to participate in the study.
The study results show that compared to women who ate less than 3 servings of red meat per week, those who ate at least 1.5 servings of red meat per day had their risk of breast cancer nearly doubled.
Previous studies have shown that cooked or otherwise processed red meat increases the risk of breast cancer in experimental animals. Researchers suspect that this similarly increases the risk of breast cancer in humans.
Other potential risk factors in red meat that may contribute to breast cancer include animal fat and an iron compound found in red meat. Research indicates that this compound plays a significant role in the development of breast cancer.