October is Breast Cancer Awareness month so I felt it would be timely to post about dietary considerations for breast cancer prevention. Are there specific nutrients and foods we should be consuming to take better care of our tatas? Certain regional diets show protection or increased risk of developing breast cancer: Traditional Oriental diets are associated with a very low risk, Mediterranean diets with an intermediate risk, and Western diets with a very high risk. So what are people eating (or not eating) that is affecting their risk of developing breast cancer? Research surrounding nutrition and breast cancer wants to focus on specific isolated factors in foods that may protect against breast cancer development. As Steve Austin, ND puts it in the book Breast Cancer: What You Should Know (But May Not Be Told) About Prevention, Diagnosis, and Treatment:
Researchers are now trying to prove that broccoli protects against cancer because of its sulforaphane content. But others say it must be the beta-carotene. Some feel the high level of vitamin C in broccoli may be responsible. Glucaric acid in broccoli has its advocates too, as does indole-3-carbinol. Who knows? It could be the fiber. Researchers are keeping busy looking for the magic bullet when they already have a veritable assault rifle to use against cancer. Attempts to attribute its effects to any on ingredient miss the boat; such efforts don't necessarily even constitute good science. Perhaps it just doesn't sound intellectual enough to say "Eat broccoli—it's good for you," though that may well be what we need to hear.
like broccoli, cabbage, and Brussels sprouts protect against cancer. There are many compounds in cruciferous veggies that have mechanisms of action that protect against breast cancer. Indole-3-carbinol (I3C) deactivates estrogen (and increased life time exposure to estrogen is linked to increased risk of breast cancer). Isothiocyanates, such as sulforaphane found in broccoli, increase the activity of enzymes that detoxify cancer-causing agents. Glucaric acid found in broccoli interferes with mammary cancer in rats, most likely due to its ability to promote the body's ability to excrete cancer-causing chemicals. (Other foods high in glucaric acid include oranges, carrots, spinach, and apples.)
Fiber in whole grains, fruits, veggies, legumes, nuts & seeds helps prevent the reactivation of estrogen by gut bacteria and reabsorption by the body. Lignans, a specific type of fiber found in the highest concentration in flaxseed, interfere with estrogen activity. Adding 2 tablespoons of freshly-ground flaxseeds to your daily diet is a simple thing you can do to increase your daily fiber consumption and protect against breast cancer.
Soybeans contain numerous compounds that protect against breast cancer. Genistein, a phytoestrogen, interferes with the formation of new blood vessels—it can cut off the blood supply to cancerous tumors. Phytoestrogens (found in all plants) bind to estrogen receptors in the body in the place of estrogen, effectively blocking estrogen and encouraging its excretion. There are some problems with soy—it has become very prevalent in our diets, it is highly allergenic and difficult to digest, and is typically genetically modified. (I will explore soy more in-depth in a future post!)
Fat, if we eat too much and the wrong type, can increase our risk of breast cancer. Research often shows mixed results, but looking carefully at the data shows us that in cultures where less than 20% of calories come from fat breast cancer incidence is lower than in cultures where greater than 20% of calories come from fat. Rates of breast cancer are even greater in cultures where 35-40+% of calories come from fat. The Nurse's Health Study reported no relationship between dietary fat and breast cancer, but these results are misleading – none of the participants were categorized into the <20% range that seems to be protective when you look at cross-cultural data. Fish and olive oils are cancer protective—their higher levels of omega-3 fatty acids reduce inflammation. Being obese increases your risk of breast cancer because the body stores estrogen in fat.
Pesticide residues collect in fatty tissues, like the breast and many have estrogenic effects. "According to the [EPA]'s own data, at least 67 currently used pesticides cause cancer in animals." If you are not vegetarian, it is especially important to eat organic animal products because pesticides in feed and hormones used in raising commercial meat are stored in the fat of the animals in high concentrations. See my previous posts about milk and beef for more information. Certain foods fruits and veggies are more important to eat organic than others—basically, the thinner the skin, the more pesticide residue. For more detailed info, check out the Environmental Working Group's 2011 Shopping guide for the "dirty dozen" and "clean fifteen."
This post is just the tip of the iceberg when it comes to eating well for cancer prevention. For more detailed information, I highly recommend the book How to Prevent and Treat Cancer with Natural Medicine by Michael Murray. I'll end with another quote by Steve Austin, ND that sums things up nicely, "Vegetables, fruit, and fish provide protection. Beans, whole grains, nonfat yogurt, and olive oil are fine. Other nonfat dairy products are okay in moderation. But most of the rest of the American diet is linked with trouble."
Yours in health,