By Brierley Wright, M.S., R.D. , September 27, 2010 - 12:21pm
In the past couple of years I’ve really scaled back how much red meat I eat. Partly because I truly enjoy meatless meals  (and it helps that I’m getting much better at cooking delicious ones!). Partly for the environmental benefits . And also for my health, which is what spurred my interest in finding an answer to this question: Does eating red meat increase a woman’s risk of breast cancer?
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Here’s what I found: A few studies do suggest that too much red meat or processed meats (e.g., bacon, cold cuts) could increase risk of breast cancer.
In a study of 35,372 British women, eating as little as 2 ounces of red meat or 1 ounce of processed meats per day was associated with increased risk of breast cancer, though the effect was greater for postmenopausal women. In another study of just premenopausal women, eating 3 ounces or more of red meat daily raised the risk of hormone receptor–positive breast cancer (a specific type of breast cancer that needs estrogen to grow).
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One explanation for the link: heterocyclic amines (HCAs), which form when meat is cooked at high heat. HCAs can act like estrogen, which may spur the growth of tumors. HCAs are produced when poultry is cooked, too, but research has yet to link poultry with breast cancer. Red meat is also high in easily absorbable heme iron, which some scientists think interacts with estrogen to promote tumor development.
Bottom line: The association between red meat and breast cancer is still tentative. Research linking red meat and processed meats with colorectal cancer is much more established, however. To reduce risk for cancers overall, the American Institute of Cancer Research recommends avoiding processed meat and eating no more than 18 ounces of red meat per week.
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How much red meat do you eat each week? Tell us what you think below.