There are a number of risk factors we can control in our Lifestyle. For ease of reference, we have grouped our discussion of the risk factors into the following six categories:
- Movement / Exercise
- Body Composition
- Night Work
- Screening and Early Detection
Movement / Exercise
In the past 50 years in the United States, we have become very sedentary in our lifestyles. Our activities of daily living require less and less physical exertion requiring us to incorporate “movement” into our healthy living plan.
Increased physical activity over a long period of time is associated with a reduced risk for breast cancer in post-menopausal women. However, 2.5-3 hours of exercise per week can decrease your risk of developing breast cancer by 18% even if the activity is not strenuous!
The benefits of physical activity are greatest for women with a low BMI but moderately overweight women also showed benefits from increased total activity. Benefits of exercise were even seen in women using hormonal therapy, a group known to have an increased risk of cancer!
The more lean muscle mass you have, the more fat you burn. This will lead to less fat remaining for estrogen production. Fat cells in our body are little estrogen factories. The more factories you have, the more estrogen you can produce!
Cardiovascular exercise should be combined with strength and resistance training to increase your lean muscle mass and to help to prevent osteoporosis.
Contrary to common misconceptions, exercise is safe after having lymph nodes removed. However, it is recommended that women with existing lymphedema only exercise with appropriate guidance (Consult your personal physician regarding your limitations and restrictions).
Obesity is defined as a Body Mass Index (BMI) of 30 or higher. A Body Mass Index is a measurement of an adult’s weight in relation to his or her height (specifically the adult’s weight in kilograms divided by the square of his or her height in meters). In the United States, we have an epidemic of obesity. Many individuals who are overweight do not realize that they are actually, by definition, obese. Obesity is the root of many significant health issues such as diabetes, hypertension, high cholesterol, breast cancer, and joint disease.
Our body composition is a risk factor that is under our control. Because lean muscle weighs more than fat, it’s not just about a number on the scale. It’s a combination of weight and fitness status!
A woman’s BMI has long been associated with an increased risk of cardiovascular disease, diabetes, and estrogen driven breast cancers.
Recent data reveals that a higher BMI/obesity has also been linked with the development of a more aggressive subtype of breast cancer that is known as a triple negative breast cancer, or ER-, PR-, Her 2 neu- cancer.
Cleary MP, Maihle NJ. The Role of Body Mass Index in the Relative Risk of Developing Premenopausal Versis Postmenopausal Breast Cancer.
Phipps A,, Mortimer J, Obesity Boost Aggressive Breast Cancer Risk. Cancer Epidemiology, Biomarkers & Prevention 2 March 2011.
In a study of 45,000 postmenopausal women, the American Cancer Society’s Cancer Prevention Study researchers found that women who gained more than 60 pounds after the age 18 were more likely to develop breast cancer than women who gained 20 pounds or less.
The group with a higher weight gain were three times more likely to be diagnosed with metastatic breast cancer and were twice as likely to have ductal cancers. Obese women also have a greater risk of breast cancer recurrence.
Cancer, July 2006
We need to heal our planet as we heal ourselves. We are only just beginning to understand how great the environmental component is on breast cancer risk.
Exposure to chemicals and toxins during breast development is likely one of our greatest opportunities for change. Due to our consumption of vegetables treated with weed killers, pesticides used on our fruits, and hormones in our meat, we are exposed to chemicals that can turn on estrogen production. Additionally, smoke in the air from factories, as well as second hand cigarette smoke are known carcinogens.
Plastic bottles, particularly when they are heated, release harmful chemicals. Plastics numbers 3, 6, and 7 should be avoided. Plastic # 7 contains BPA ( Bisphenol A), a chemical that may be harmful to brain function and child development.
Follow these rules for safe plastic use:
Cooking and Cleaning
- Cook and heat in safe containers
- Avoid nonstick pans
- Do not heat in plastic
- Use safe personal care products
- Use GREEN household cleaning products
- Do not let bottled beverages get warm
- Drink filtered tap water
- Poach, boil and steam your foods
- Eat grass fed meats, free range chicken, and wild-caught fish
- Whenever possible, eat organic fruits and vegetables labeled with the organic seal:
- Refer to the following chart for the Dirty Dozen and Clean 15 fruits and vegetables
Think Pink Live Green
The HCF in conjunction with BreastCancer.org, created this educational brochure that includes 31 ways to decrease your risk of developing breast cancer. Click on the image to view the brochure.
Avoid Exogenous Estrogen – “Estrogen is estrogen”
Estrogen is the “fuel” on the fire. While it doesn’t cause cancer, it can accelerate its growth. You should be aware of the risk of taking estrogen regardless of its form. Bio-identical estrogen is still estrogen and is not always without risk. Discuss any use of estrogen with your physician.
In 2003, the Women’s Health Initiative found that breast cancer incidence rates were increased when estrogen and progesterone were taken in combination. (i.e. Premarin and Provera)
Despite that, these breast cancers were found earlier, were thought to be more treatable, and had better prognosis tumors. Many women still discontinued the use of the combined hormones at that time as they were concerned that the risks were greater then the benefits. Following this decrease in hormone replacement, a big decrease in breast cancer diagnoses was seen in the years that followed.
In 2010, the WHI follow up study revealed that there was actually an increase in the incidence of breast cancer with women on estrogen and progesterone. These women were twice as likely to have an increase in the incidence of lymph node positive breast cancer and an increased risk of dying from their breast cancer. More research is needed to determine the safety of estrogen-only replacement.
Hiatt RA, Haslam SZ, Osuch J; Breast Cancer and the Environment Research Centers. The breast cancer and the environment research centers: transdisciplinary research on the role of the environment in breast cancer etiology.. Environ Health Perspect. 2009 Dec;117(12):1814-22. Epub 2009 Jun 16. Review. PubMed PMID: 20049199; PubMed Central PMCID: PMC2799453.
Chlebowski RT,Anderson GL, Gass M et al WHI Investigators. Estrogen plus progestin and breast cancer incidence and mortality in postmenopausal women. JAMA. 2010 Oct 20;304(15):1684-92. PubMed PMID: 20959578
JAMA, October 20 2010-Vol 304 No 15
In 2007, the Agency for Research on Cancer classified shift work that disrupts our natural circadian rhythm as a “probable” carcinogen in humans. There are increasing numbers of women working shift work, experiencing frequent time zone changes, insomnia, and sleeping in room with light sources. 8 out of 12 epidemiologic studies prior to this study reported a positive association between night work and breast cancer. Because darkness signals the brain to produce melatonin, exposure to light at night suppresses melatonin production. This can inhibit melatonin’s anti-carcinogenic mechanisms produced through an increase in natural killer cells and immune function. Women who have not had their first child or breastfed are at greatest risk as full differentiation of the mammary gland does not occur until lactation.
Reducing your risk:
Women who already have significant risk profiles or with current or prior breast cancers need to consider the increased risk for them, as do nuliparis women (women who have not had a child). You can help change this risk by considering childbearing earlier in life and realizing that our lifestyle has a significant impact on our risk of developing the most prevalent types of breast cancer.
Further studies need to evaluate melatonin supplementation and blue light restriction glasses. Currently, there is no indication for increased mammographic screening!
Night work and breast cancer: a population-based case-control study in France,
International Journal of Cancer, Florence Menegaux, et al, 10.1002/ijc.27669 June 2012.
Screening and Early Detection
Various organizations have set mammographic screening guidelines. The American Cancer Society, American College of Surgeons, American College of Radiologists, and The American College of Obstetrics and Gynecology recommend receiving a baseline mammogram between the ages of 35 and 40 then receiving an annual mammogram from the age of 40 on. If you are a BRCA carrier or at high risk for breast cancer (greater than 20% Gail risk), it is recommended that you receive an annual MRI. For women with dense breasts, it is recommended that you receive a 3-D tomosynthesis mammogram for screening purposes.
For all women, an annual clinical breast exam and monthly breast self exam are recommended. If a woman or a man feels a mass in their breast, they need to have it evaluated by a surgeon even if all of the imaging studies are negative. (20% of all breast cancers are found where there are no abnormal images!)