We all know that obesity can lead to a variety of serious health conditions, but a surprising study is adding a new one to the list: breast cancer. The health study of over 155,000 patients revealed that the heaviest women were 35% more likely than the thinnest women to develop triple-negative breast tumors.
In the past, obesity has been linked to increased risk of estrogen-sensitive tumors, as fat is a source of estrogen production in women, but these findings that connect obesity to tumors not fueled by estrogen was surprising to experts.
While shocking, these findings also reinforce the importance of maintaining a healthy weight. By exercising regularly and avoiding obesity, women may be able to lower their risk of estrogen-sensitive tumors and triple-negative breast tumors. Even a weight loss of only 5 to 10 percent of total weight can provide health benefits.
In 2001, experts with the National Cancer Institute concluded that cancers of the colon, breast (postmenopausal), endometrium (the lining of the uterus), kidney, and esophagus are associated with obesity. They also suggested that obesity and physical inactivity may account for 25 to 30 percent of several major cancers— including colon, breast (postmenopausal), endometrial, and kidney cancers.
Another factor related to the higher breast cancer death rates in obese women is that breast cancer is more likely to be detected at a later stage in obese women than in lean women. This is because the detection of a breast tumor is more difficult in obese versus lean women.