When Americans think of breast cancer, most consider it to be like a game of craps. If a woman is lucky she will avoid breast cancer during her lifetime, but if she is unlucky, then she may be diagnosed with this dreadful disease. This philosophy on breast cancer is unfortunately perpetuated in the United States health care system.
We doctors, nurses, and other health professionals learn early in our educations that breast cancer is virtually inevitable for many women. Currently, the lifetime risk of breast cancer in an American woman is about 12%. In other words, a female born in the United States has about a 1 in 8 chance of developing breast cancer during her lifetime.1 This is one of the highest breast cancer rates in the entire world. It is well known that rates of breast cancer are substantially lower in many developing countries where diets consist of more plant-based whole foods (and less animal-based foods) and where lifestyles are generally less sedentary. For example, compared with a 12% lifetime breast cancer risk in the US, there is only a 3% lifetime risk in East Asia, Central and sub-Saharan Africa, and Western sub-Saharan Africa.
In the United States, our approach to breast cancer is tailored around its inevitability. As a result, instead of investing substantial research into dietary and lifestyle prevention of this disease, we prefer to focus instead upon early diagnosis and treatment. Techniques used for diagnosis most often include physical examination, mammography, ultrasound, and biopsy procedures. Such screening simply identifies cancers that have been around long enough that they have grown to where they can be detected. Breast cancer treatments often include surgery (e.g., mastectomy or lumpectomy), radiation, and chemotherapeutic agents. These approaches to breast cancer are unfortunately reactive, similar to how we typically approach many other diseases in our country, including heart disease, stroke, and hypertension.
“Wait until the disease is diagnosed. Then prescribe drugs and perform surgery.”
This approach ignores the root causes of these diseases, which is principally our diet and lifestyle.
Key risk factors for breast cancer include early age of menarche, late age of menopause, high levels of female hormones in blood, and high blood cholesterol. These were confirmed in the China Study and have been documented in many other research studies.2 With the exception of the blood cholesterol, these risk factors are all related to exposure to excess female hormones, such as estrogen and progesterone, which increases breast cancer risk. Women who consume diets rich in animal-based foods and relatively low in plant-based whole foods have menarche earlier and menopause later, resulting in greater lifetime exposures to estrogen. This explains why research has shown that lifetime exposure to estrogen is 2.5-3 times higher among Western women when compared with rural Chinese women.2 Estrogen is a direct participant in the breast cancer process.3 Its levels are a key determinant of breast cancer risk. High levels of estrogen and other female hormones result from consuming typical Western diets, high in fat and animal protein, but low in dietary fiber.4 This research strongly suggests that the risk of breast cancer can be markedly reduced simply by eating foods that keep estrogen levels at lower levels than is typical with the Standard American Diet (SAD).
Instead of addressing preventable dietary causes of breast cancer, we prefer to discuss other risk factors, including genes, hormone replacement, and environmental toxins. While it is true that genes play a role in breast cancer, it is wrong for women to feel that if they have a family history of breast cancer, there is nothing they can do to decrease their risk. This is simply untrue and it removes personal responsibility from the equation. In truth, most breast cancer is much more strongly tied to diet and lifestyle than to genes. Even in women who have so-called “breast cancer genes,” those genes would need to be expressed in order for breast cancer to manifest. Whether such genes are expressed is closely related to one’s diet and lifestyle.5 Hormone replacement therapy is considered a risk factor for breast cancer. As discussed previously, exposure to female reproductive hormones during the course of a woman’s life increases her breast cancer risk. Therefore, it is no surprise that administering these hormones as therapy in postmenopausal women would also increase breast cancer risk. The good news is that consuming a plant-based diet (as opposed to the typical American animal-based diet) reduces the abrupt hormone changes that typically cause menopausal symptoms and may make such hormonal therapy unnecessary in many women.5 Environmental chemicals such as dioxins, Polychlorinated Biphenyls (PCBs), and Polycyclic Aromatic Hydrocarbons (PAHs) have also been discussed as increasing a woman’s breast cancer risk. While such chemical exposures may contribute to carcinogenesis, it is important to realize that with similar chemical exposures, a plant-based diet has been shown to be protective against cancers, while an animal-based diet is more conducive to cancer cell growth.5
A review of more than sixty research studies suggests that premenopausal and postmenopausal women who exercise regularly may reduce their incidence of breast cancer by 20-40%.6 Also, a study of nearly 3,000 nurses with stages 1, 2, or 3 breast cancer published in The Journal of the American Medical Association indicated that simply walking three to five hours per week reduced the risk of breast cancer by 26 to 40%.7
Stress also seems to play a role in breast cancer. A study following nearly 60,000 African American women for six years found that women who reported feelings of racial discrimination were more likely to develop breast cancer than their peers.8
In summary, based on much research to date, there is reason to believe that the following may significantly reduce your risk of breast cancer … and that of your patients:
- Depart from the SAD, which is high in animal-based and processed foods, and instead adopt a plant-based, whole-food diet that is high in nutrients and fiber.
- Engage in regular exercise.
- Reduce your stress levels through prayer, yoga, meditation, and mutually supportive relationships.
Don’t sit back and let breast cancer find you. Be proactive and reduce your risk of this terrible disease in the first place. As health care providers, we can do more than merely suggest mammograms for our patients. We must educate them on dietary and lifestyle changes to prevent this terrible disease from happening in the first place.
- Forouzanfar MH, Foreman KJ, Delossantos AM, et al. Breast and cervical cancer in 187 countries between 1980 and 2010: A systematic analysis. Lancet. 2011 Oct 22;378(9801):1461-84.
- Junshi C, Campbell TC, Junyao L, Peto R, eds. Diet, Life-style and Mortality in China: A Study of the Characteristics of 65 Chinese Counties. Oxford, UK; Ithaca, NY; Beijing, PRC: Oxford University Press; Cornell University Press; People’s Medical Publishing House; 1990.
- Bocchinfuso WP, Lindzey JK, Hewitt SC, et al. Induction of mammary gland development in estrogen receptor-alpha knockout mice. Endocrinology. 2000 Aug;141(8):2982-94.
- Adlecreutz H. Western diet and Western diseases: some hormonal and biochemical mechanisms and associations. Scand J Clin Lab Invest Suppl. 1990;201:3-23.
- Campbell TC, Campbell TM II. The China Study. BenBella Books; 2006.
- Exercise and malignancy: Can you walk away from cancer? Harv Mens Health Watch. 2006 Nov;11(4):4-6.
- Holmes MD, Chen WY, Feskanich D, Kroenke CH, Colditz GA. Physical activity and survival after breast cancer diagnosis. JAMA. 2005 May 25;293(20):2479-86.
- Taylor TR, Williams CD, Makambi KH, et al. Racial discrimination and breast cancer incidence in U. S. black women: The Black Women’s Health Study. Am J Epidemiol. 2007;166(1):46-54.