Can exercise really help decrease your risk for breast cancer? Research and retrospective studies published in the last few years suggests there is a truly significant benefit from exercise. Aside from the benefits to your cardiovascular system and your overall health, exercise can reduce your risk of dying from breast cancer.
According to research published in December 2013 in the Public Library of Science, even small amounts of regular exercise, such as regularly going on short runs or walks, potentially lowered a woman’s risk of dying from breast cancer by more than 40 percent.
For the study, researchers at the Lawrence Berkeley National Laboratory followed 79,124 women, all of whom were either runners or walkers, for 11 years. None of them had been diagnosed with breast cancer at the start of the study, and they all reported the distances they ran or walked each week, as well as their bra cup size, body weight, and height.
Researchers found that the women who met the Centers for Disease Control and Prevention’s current aerobic exercise guidelines (that’s two and a half hours of moderate activity or an hour and 15 minutes of vigorous activity a week) were 42% less likely to die of breast cancer during the study than those whose exercise fell short of the guidelines—even after adjusting for body mass index (BMI).
What’s the secret? Exercise reduces estrogen’s effect on cancer by altering how the body breaks down the hormone into either harmful or benign byproducts, according to previous research in Cancer Epidemiology, Biomarkers & Prevention.
Similarly, researchers in France looked at studies that involved more than 4 million women around the world who participated in prospective studies from 1987 to 2013. They found that the more active a woman is, the better her odds of avoiding breast cancer. Women who were most active, with more than an hour a day of vigorous activity, got the most benefits, lowering their cancer risk by at least 12 percent. Women who were overweight or obese benefited a little less, but still lowered their risk by 10 percent overall.
While the study in the Public Library of Science found breast cancer risk reductions as high as 42 percent from physical activity, the huge number of women included in the retrospective study performed by the Strathclyde Institute for Global Public Health suggests that the 12 percent reduction in breast cancer risk is more accurate. More activity was better, but anything was better than nothing.
So, if you want to significantly reduce your risk for breast cancer, moderate exercise such as walking briskly for a total of two hours per week will do the trick. If you’re strapped for time, about an hour of running each week will be just as effective. Running and walking offer the same breast cancer protection. At higher intensities, it just takes less time to expend the required amount of energy.
Bottom line: Regular exercise reduces a women’s risk of breast cancer, regardless of the type of exercise or the age when you begin exercising. Combined with getting a mammogram starting at 40, keeping your weight in check, and eating a mostly plant-based diet you can significantly reduce your risk of breast cancer.
About the author: Raja P. Reddy, MD is a board certified diagnostic radiologist specializing in breast imaging. He is also a contributing editor for Digital Mammography Specialists, a leading provider of outpatient women’s imaging services in the greater Atlanta, GA area.