It’s safe to say that any breast cancer survivor who’s been through treatment wants to avoid having to go through it again. The risk of breast cancer recurrence is highly individual and varies according to the type and the stage of breast cancer you had. But a new research review published in the Canadian Medical Association Journal, or CMAJ, sheds light on how various lifestyle changes may be able to improve anyone’s odds of preventing a breast cancer recurrence. 

The most important one: exercise. The review authors found it can reduce a breast cancer recurrence by 40 percent. According to the study authors, "physical activity has the most robust effect of all lifestyle factors on reducing breast cancer recurrence."

“Exercise has a benefit that’s separate from weight control. It regulates hormone levels, improves insulin resistance, and reduces inflammation,” says study co-author Ellen Warner, M.D., a professor of medicine at the University of Toronto and a medical oncologist at Toronto’s Sunnybrook Odette Cancer Centre. 

Exercise can also help the depression, fatigue, lymphedema (swelling in the arm caused by removing lymph nodes), and stress that might accompany diagnosis and treatment, according to Susan Gilchrist, M.D., an associate professor of clinical cancer prevention and cardiology at the University of Texas MD Anderson Cancer Center in Houston.

How Much, How Often?

In the study, the researchers say that breast cancer survivors should be encouraged to get at least 150 minutes of moderate-intensity or 75 minutes of vigorous aerobic exercise (brisk walking, cycling, running, or aerobic classes) in addition to at least two strength-training sessions weekly. That's the same amount of exercise the U.S. Department of Health and Human Services guidelines recommended for all of us.

Always get your doctor’s clearance before you begin an exercise program, especially if you’ve had breast surgery. Work with a physical therapist at first to make sure your workout is appropriate for your range of motion, Gilchrist advises.

Walking, says Gilchrist, is a great place to start for most breast cancer patients. (You can find a personal trainer who’s certified to work with cancer patients at the American College of Sports Medicine website.) The study authors also point out that many hospitals and cancer-care centers now offer exercise programs for breast cancer survivors, so check with your doctor.

Other Key Moves

The study authors found that keeping your weight steady is important. Unfortunately, most breast cancer survivors do put on pounds.

“There are a variety of factors at play, but there is something about breast cancer that makes patients more likely to gain weight,” says Warner. “Plus, chemotherapy slows the metabolism. If you eat and exercise the same way you always have, you will get heavier.”

"On average, a woman will gain 10 to 12 pounds,” Gilchrist says. Exercise will help, she says, but you might need to do 200 minutes or more per week.

Dietary changes (such as following the Mediterranean diet) didn’t seem to make a difference in breast cancer recurrence rates, according to the researchers, although eating foods high in saturated fat was related to an increased risk of dying from breast cancer.

In addition, the researchers found that eating soy products was not linked to breast cancer recurrence. There is also some preliminary evidence that low blood levels of vitamin D might increase death rates and that getting more vitamin C could help prevent breast cancer recurrence, but the authors note more research is needed.