Body Fat, BMI, and Breast Cancer

10 December 2018

Being overweight after menopause is associated with an increased risk of breast cancer. But a new study suggests that our traditional measure of overweight, the body mass index (BMI) may not tell the whole story.

A recent study, published in JAMA Oncology, performed detailed body composition analysis on 3000 women who were of normal BMI. They found that among these women, those with increased levels of body fat (especially in the truncal area – “belly fat”) had higher risks of estrogen receptor positive (ER+) breast cancer compared to women with lower body fat levels. In addition, the women with higher body fat levels also had higher levels of inflammatory markers as well as other metabolic abnormalities. 

This suggests that maintaining a healthy weight may not be enough. Muscle mass declines with age, so even if weight is stable, there is a slow but steady increase in body fat. Regular exercise can certainly help to maintain muscle mass and it also helps decrease the level of inflammatory markers. 

The authors note that more study is needed to better understand the links between body fat and breast cancer, but it is very clear that there is no way around it – exercise is essential for good health.

Additional Information:
NBC News: Belly fat increases risk of breast cancer despite normal BMI
CNN – Body fat levels linked to breast cancer risk in post-menopausal women

DISCLAIMER:
Dr. Attai does not provide online medical advice. The information provided on this website is for general information only. No online site should be used as a substitute for personal medical attention.The opinions expressed on this site are those of Dr. Attai and do not represent the opinions of UCLA Health.