It is settled science that a high body mass index is a risk factor for postmenopausal breast cancer. What is still up for debate is whether weight loss after menopause lowers that risk. According to a new study published in the Journal of the National Cancer Institute, the answer is yes.
The study included over 180,000 women of the age of 50 (6,930 were eventually diagnosed with breast cancer). Researchers tracked their weight change patterns over the course of ten years. The results are promising, in that they indicate that postmenopausal women have a degree of control over their risk of developing this oftentimes deadly disease.
According to a summary of the study’s results, “Compared with women with stable weight (± 2kg), women with sustained weight loss had a lower risk of breast cancer. This risk reduction was linear and specific to women not using postmenopausal hormones.”
As you might imagine, the more weight you lose, the lower your risk becomes.
Interestingly, the weight loss doesn’t necessarily have to be permanent. The study found that women who lost significant weight (more than 9kg, or about 20lbs), and subsequently gained some or even most of it back, still had a decreased risk of breast cancer.
“Other patterns of weight loss and gain over the two intervals had a similar risk of breast cancer to women with stable weight,” the authors write, concluding, “These results suggest that sustained weight loss, even modest amounts, is associated with lower breast cancer risk for women aged ≥50 years. Breast cancer prevention may be a strong weight loss motivator for the two-thirds of American women who are overweight or obese.”
Lauren Teras, PhD, the study’s lead author, stressed that it’s never too late to start shedding weight.
“These findings may be a strong motivator for the two-thirds of American women who are overweight to lose some of that weight,” she said. “Even if you gain weight after age 50, it is not too late to lower your risk of breast cancer.”