In her New York Times article, “You Can Take Steps to Lower Your Breast Cancer Risk,” author Jane Brody outlines lifestyle changes women can make to lower their risk of breast cancer⁽¹⁾.

Smoking and breast cancer

According to Brody, one of the most important things women can do to reduce their risk of breast cancer is not smoke. She cites a study of more than 100,000 women conducted in northern Europe that compared nonsmokers to those who smoked 10+ cigarettes a day for 20 or more years⁽²⁾. The women who smoked had a one third higher risk of developing invasive breast cancer than those who did not smoke. In addition, girls who started smoking before age 15 were nearly 50% more likely to get breast cancer. 

In her article, Brody shares data from an editorial in The Journal of Clinical Oncology that outlines data that supports the conclusion that as many as 20,000 women in the U.S. continue to smoke even after a breast cancer diagnosis as well as data that show that smoking can have a negative effect on how well treatment (chemotherapy and radiation) will work for breast cancer patients.

Avoiding alcohol

Like smoking, drinking alcohol can impact breast cancer risk. Studies have shown that women who consume 2-5 drinks a day are 40% more likely to get breast cancer than nondrinkers. Even one drink a day can raise a woman’s cancer risk by almost 7%.

Alcohol use can also affect hormone levels. Increased levels of certain hormones can increase breast cancer risk in both pre- and post-menopausal women. And for women diagnosed and treated for breast cancer, consuming 3-4 drinks a week can increase their risk of recurrence especially in post-menopausal or overweight women. Brody states that moderation is key when considering alcohol’s potential to increase breast cancer risk. 

Watching your weight

Studies have shown that as body mass index (BMI) increases, so does a woman’s risk of breast cancer. This link is especially true if the extra weight is around the waist. Abdominal fat can produce growth factors and hormones that can stimulate breast cancer cells to grow. Maintaining a healthy weight is important both before and after a cancer diagnosis because being overweight not only increase a woman’s risk of getting breast cancer, but also can lower her chance of surviving the disease.

Diet

Paying attention to diet can lower women’s breast cancer risk. Following a heart-healthy diet can reduce risk of many diseases, including breast cancer. Healthy eating can help women maintain a healthy weight. Fiber-rich vegetables, fruits, and whole grains are good choices while limiting proteins high in saturated fats (red meat), as well as sugar-sweetened foods and drinks.

Brody shares information about some other specific food choices:

• Some studies have found the lowest risk of breast cancer among women who ate the most fruits and vegetables. However, the greatest protection was found when these healthy eating habits started early in life, not after a breast cancer diagnosis.
• Carotenoids – the orange colored plant pigments found in sweet potatoes, carrots, winter squash, cantaloupe and tomatoes – as well as dark-green, leafy vegetables such as spinach and kale are especially protective against breast cancer.
• Soy contains isoflavones that may play a protective role against breast cancer. Asian women -- who eat soy throughout their lives -- have one of the lowest breast cancer rates in the world. However, soy does not seem to show any benefit in women who eat a Western diet. Brody also suggested avoiding isoflavone supplements, which contain a high-concentration of plant-based estrogen.
• Finally, Brody points out that a number of studies have shown a diet high in saturated fats (red meat and processed meats) can increase cancer risk and that the American Cancer Society (ACS) recommends limiting red meat to two meals a week and avoiding processed meats when possible. The ACS also suggests limiting high-fat dairy foods such as cheese, ice cream, and whole milk because they can contain hormones that may stimulate cancer cell growth.

Staying physically active

Many studies have shown that women who exercise regularly have a lower risk of breast cancer. In addition, staying active after a breast cancer diagnosis can lower your chance of dying from the disease. According to Brody, even simple exercise such as brisk walking at least 30 minutes a day can offer benefit. 

What does this mean for me?

It is important to understand that this article shares actions individuals can take to lower their breast cancer risk, but not necessarily prevent breast cancer entirely. There is no direct cause-and-effect relationship between these lifestyle factors and cancer prevention. While we do know that such things as eating a heart-healthy diet can reduce the risk of many diseases, not just breast cancer, there is no way to completely eliminate breast cancer risk.  Even if you have no family history, no known inherited mutation, do not smoke, drink in moderation, and maintain a healthy diet and weight, you may still be diagnosed with breast cancer. Finally, little is known about the degree to which the lifestyle changes described in this article impact risk for individuals who are already at high risk due to family history, an inherited mutation, or a previous breast cancer diagnosis.

Patients should discuss their individual breast cancer risk and how changes in lifestyle may effect that risk with their health care provider. 

Questions to ask your health care provider

• What is my risk of breast cancer?
• Given my risk, what are some things I can do to lower that risk or prevent a recurrence?
• What can I do to help my children reduce their risk of breast cancer?

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Posted 9/21/17

References

New York Times: You Can Take Steps to Lower Your Breast Cancer Risk.

Parker BA and Pierce JP. Importance of Smoking Cessation to Reduce Breast Cancer Mortality. J Clin Onc.2016. 34(12):1295-6.