The December 2007 issue of Cancer Causes and Control published a new report according to which an inactive lifestyle lacking physical activity or exercise increases the risk of breast cancer.
This report which is compiled by the South Western Medical center, University of Texas’s Coyle Y.M., says that estrogen levels are lowered due to exercise. A higher level of estrogen carries with it a risk of breast cancer.
Proliferation of the epithelial cell in the breast is increased, the tumor suppressor genes are silenced and the estrogen metabolism to genotoxic metabolites increases due to increased levels of estrogen which in turn increases the risk of breast cancer.
Author also points out that studies on animals reveal that an increase in physical activity promotes cellular apoptosis and proliferation thereby slowing the growth of breast tumor. Though limited, human studies too show similar results. Hypermethylation of TSGS which is a promoter of breast carcinogenesis is reduced by more exercise according to Coyle.
Coyle concludes by saying that further research and studies are required to conclusively prove that exercise reduces risk of breast cancer.
A recent study conducted by the National Cancer Institute led by James McClain involving 5968 women showed evidence that more physical exercise reduced the risk of development of cancer in general.
Another study by the National Cancer Institute led by Freedman DM and his colleagues also point out a relationship between exercising and breast cancer in women. This study was published on the October 21st 2008 issue of Cancer Causes and Control.
