Brandel France de Bravo, MPH and Diana Zuckerman, Ph.D., Cancer Prevention and Treatment Fund
Here’s the good news about how to cut your risk.
1. Lose weight (Diet and Exercise)
Numerous studies show that overweight and obese women are more likely to develop breast cancer.1 Estrogen, a female hormone, provides nutrition for most breast cancers. The more fat cells you have, the more estrogen you have circulating in your body. Maintaining a healthy weight is like telling breast cancer cells that the restaurant is closed for business! The healthiest way to lose weight and to keep your weight down is to reduce the number of calories you eat and also to exercise. Exercise helps prevent breast cancer and also helps women who were diagnosed with breast cancer live longer. 2 You don’t need to become a Serena Williams or Brittney Griner. You just need to move! Walk at least part of the way to work, take the stairs instead of the elevator and pump iron (or choose the exercise of your choice) while you’re on the phone.
2. Avoid unnecessary hormones
Hormone therapy increases your risk of breast cancer, so avoid it if you can. If you’re taking hormone therapy, use it at the lowest possible dose for the shortest time – or just get off it as soon as possible. Also reduce your exposure to chemicals that act like hormones. Bisphenol A (BPA) is a chemical used in clear, hard plastic and in the linings of canned foods, canned drinks, disposable cutlery and many other common items, including baby bottles. BPA, phthalates (“Thah-lates”) and other chemicals known as “endocrine disruptors” appear to increase the risk of obesity, diabetes, early puberty in girls, and possibly the risk of breast cancer and prostate cancer. Here are some tips to limit your exposure to BPA:
- Use frozen or fresh vegetables and fruits instead of canned. Get rid of older canned goods, especially if they contain tomatoes and other acidic fruits since the acid accelerates the leaching of BPA from can linings into the food. If you buy tomato or pasta sauce, look for brands sold in glass jars. Eden is one of the few brands of canned foods that doesn’t use BPA in the linings of its cans (except for its tomato products).
- Look for drinks sold in glass, plastic bottles (soft plastic bottles like the ones typically used for soft drinks and water don’t have BPA), or cartons like those used for milk. Some of the glass bottles have tops lined with BPA but at least the top is not in constant contact with the beverage. If you carry a reusable water bottle, switch to stainless steel or look for the newer BPA-free sports bottles.
- Switch to glass, porcelain, or stainless steel containers for hot foods and drinks because the heat is more likely to break down the BPA in the plastic and introduce it into your food or beverage.
- When you microwave, use glass or ceramic, stoneware, or bone china containers. You can use any kind of non-plastic dishes and bowls as long as they don’t have gold or silver trim. If you need to cover the food to keep it from splattering in the microwave, use another dish or paper towel. Don’t microwave food or beverages in plastic or disposable containers (not even the ones they are sold in), and don’t cover dishes with plastic wrap in the microwave oven. Plastics that contain BPA are usually very hard and may have a triangle on the bottom with “7” inside or may say “PC.” Not all plastics with a Number 7 contain BPA, but all plastics break down when exposed to heat-whether in the microwave or the dishwasher-and strong soaps.
Phthalates, another endocrine disrupting chemical, have been linked to genital abnormalities in boys and men, and to early puberty in girls. While there is no proven link to breast cancer yet, anything that affects hormones has the potential to affect breast cancer. Phthalates are used to soften plastics and add fragrance to personal care products like lotions, shampoos, and make-up. When they aren’t used as part of the fragrance, they are sometimes used to mask the natural smell of the chemicals in a product. Phthalates are everywhere-except on a product’s label. Phthalates are almost never listed as an ingredient if their use is related to the way a product does or doesn’t smell. You can minimize your exposure to phthalates by using shampoos, hair spray, deodorants, lotions, perfumes, make-up and nail polish that are phthalate free. If the product doesn’t state “phthalate-free” (and few do), visit the Environmental Working Group’s Cosmetic Safety Database to find out which of your favorite products are safe. If you are not sure if a product has phthalates, choose the version that says “fragrance-free.”
3. Reduce stress
Reduce stress through regular exercise, meditation, or engaging in hobbies or activities that relax and fulfill you. You’ll never be able to eliminate stress from your life but you can learn to manage it better. If for you de-stressing includes watching television or “screen time,” try not to eat while doing it as people tend to eat more when they’re focused on something other than the food in front of them. If you’re going to snack, choose low-fat, nutrition-dense foods like fruits and low-fat yogurt or cheese and unsalted nuts.
4. Eat the right foods
Some foods have been shown to increase your risk of breast cancer and others appear to help prevent breast cancer (or breast cancer recurrence). Eating more than 3-4 portions of red meat like beef, pork and lamb can increase your risk of several cancers, including breast cancer. So, try to eat those meats less often, and smaller portions. Several studies have found that women who eat lots of fresh fruits and vegetables are at lower risk of breast cancer or breast cancerrecurrence. A study of post-menopausal women who ate a Mediterranean diet (lots of fresh fruits and vegetables, fish, and olive oil) also found a decrease in breast cancer, especially for women who supplemented their Mediterranean diet with more extra virgin olive oil.3 And a study of premenopausal women found that those who ate a lot fruits and vegetables with carotenoids in them had a lower risk of developing breast cancer. Carotenoid-rich foods are leafy greens like kale, spinach and collard greens and foods that are orange, red and sometimes yellow. They include: carrots, mangoes, apricots, squash, sweet potatoes, and tomatoes. And if you don’t like your veggies plain, you can add cayenne pepper or chili pepper for an extra dose of carotenoid!
It’s too soon to say if walnuts can reduce cancer risks, but one study found that they reduced the frequency and size of breast cancer tumors in mice.
5. Breastfeeding protects
If you are planning to have a child or add to your family, strongly consider breast feeding. Not only is breast milk good food for your baby, but the more you breast feed, the lower your risk of various cancers, including breast cancer. This is especially important if you got a late start on having a family, because delayed childbearing increases your breast cancer risk slightly—unless you have one of the BRCA breast cancer gene mutations. If you have BRCA1 or BRCA2, having children late in life or having no children at all does NOT add to your already elevated risk of breast cancer. Breastfeeding may lower the risk of breast cancer for women with BRCA1, but not for women with BRCA2. To read more about BRCA mutations and breast cancer risk, click here. http://www.ncbi.nlm.nih.gov/pubmed/12133652
6. Don’t smoke (or quit, if you do)
A United Kingdom study involving over 100, 000 women found a significant link between smoking and breast cancer. Over a 7-year period, about 2% of women who ever smoked developed cancer compared to about 1.6% of women who never smoked.4 This means that smoking causes about 4 in 1000 breast cancers. Even though that number seems small (less than half a percent), it is statistically significant. Starting smoking at a younger age, smoking 15 or more daily cigarettes, and smoking for at least 10 years increase the chances of developing breast cancer. If you smoke, you should talk to your doctor about ways to quit. Quitting decreases the chances of developing breast cancer, but it may take about 20 years to see the full benefits. To read more, click here.
All articles are reviewed and approved by Dr. Diana Zuckerman and other senior staff.
1 Neuhouser ML, Aragaki AK, Prentice RL, et al. Overweight, Obesity, and Postmenopausal Invasive Breast Cancer Risk: A Secondary Analysis of the Women’s Health Initiative Randomized Clinical Trials. JAMA Oncol. Published online June 11, 2015. http://oncology.jamanetwork.com/article.aspx?articleid=2319235
2 Chen et, al. Association of physical activity with risk of mortality among breast cancer survivors. JAMA Netw Open.2022;5(11):e2242660. doi:10.1001/jamanetworkopen.2022.42660
3 Toledo, Estefanía, et al. Mediterranean Diet and Invasive Breast Cancer Risk Among Women at High Cardiovascular Risk in the PREDIMED Trial A Randomized Clinical Trial. JAMA Intern Med. Published online September 14, 2015. doi:10.1001/jamainternmed.2015.4838. http://archinte.jamanetwork.com/article.aspx?articleID=2434738&utm_source=Silverchair%20Information%20Systems&utm_medium=email&utm_campaign=ArchivesofInternalMedicine:OnlineFirst09/14/2015
4 Jones ME. et al. Smoking and risk of breast cancer in the Generations Study cohort. Breast Cancer Research. 2017;19:118. https://doi.org/10.1186/s13058-017-0908-4