Excess body fat levels, even if it’s linked to an average body mass index (BMI), could expose post-menopausal women to higher breast cancer risks. At least, that’s the result of a recent study published last Thursday in the medical journal JAMA Oncology.
“We do find that excess body fat in those who are post-menopausal with a normal body mass index is associated with about a doubling in the risk of estrogen-dependent breast cancer,” said Dr. Andrew Dannenberg, one of the authors of the new study, and the director of cancer prevention at the Sandra and Edward Meyer Cancer Center at Weill Cornell Medicine.
According to the American Cancer Society, the ER-positive breast cancer on which the new study focused, and which is estrogen-dependent cancer, installs in the body when proteins receptors in cancer cells bind to the estrogen hormone and depend on it to grow.
Body Fat Levels Might Cause Breast Cancer In Post-Menopausal Women
In their study, the scientists analyzed 3,460 American post-menopausal women between the ages of 50 and 79 who participated in the Women’s Health Initiative. Out of the 3,460 women who had their body composition measured, about 146 developed ER-positive breast cancer. They looked further on that group of women to connect breast cancer to body fat levels.
The researchers found that a 5-kilogram (11-pound) increase in whole-body fat mass triggers a 35% increase in the risks of ER-positive breast cancer. Also, a 5-kg increase in the fat mass at the trunk level causes a 56% surge in the breast cancer risks.
“The main takeaway is that having excess body fat, even when you have a normal body mass index, is associated with an increased risk for breast cancer,” said Dannenberg.
“I think it’s a good step forward that takes us from looking at the BMI as an indicator of obesity to really looking at the particular site of the fat concentration in the body,” added Hoda Anton-Culver from the Department of Medicine at the University of California, Irvine.