Increase stress levels to lower Br Ca risk?

It seems chronic stress has a fringe benefit: It protects women from breast cancer. A recent prospective cohort study of almost 7,000 women participating in the Copenhagen City heart study finds that women with self-perceived high levels of stress have a 40% lower risk of first-time primary breast cancer than less stressed counterparts.

During 12 years of follow-up, 251 women in the study were diagnosed with breast cancer. Compared with women with low stress levels, those who were highly stressed had a hazard ratio of 0.60 (95% CI; 0.37–0.97) for breast cancer. In addition, each increase in stress level on a 6-point stress scale was associated with an 8% lower risk of primary breast cancer (hazard ratio [HR] 0.92; 0.85–0.99).

The researchers surmise the connection is based on the ability of chronic stress to impair estrogen synthesis, and high endogenous concentrations of estrogen are a known risk factor for breast cancer. The authors of the study caution, however, that the cumulative health effects of ongoing, intense stress may outweigh the protection offered against breast cancer.